Comfort Systems USA (FIX) 10-K risk factor changes: FY2021 vs FY2020

Any period of economic recession, including the ongoing recession caused by the Coronavirus Disease 2019 (“COVID-19”) pandemic, affecting a market or industry in which we transact business is [removed: likely to adversely impact our business.]

Additionally, because 5.7% of our revenue for the year ended December 31, [removed: 2020] [added: 2021] was attributable to projects in the government sector, a reduction in federal, state, or local government spending in our industries and markets could result in decreased revenue and profit for us.

Our backlog as of December 31, [removed: 2020] [added: 2021] was [removed: $1.51] [added: $2.31] billion.

| | ● | governmental guidance or requirements, including work-from-home [removed: policies,] [added: policies and vaccine mandates,] or potential illness that negatively impact the availability or productivity of our key personnel or a significant number of employees or cause other disruptions to our business, corporate governance or financial reporting processes; |

| | ● | [added: potential supply chain disruptions and] limitations on the ability of our suppliers, vendors and subcontractors to perform; |

If we are unable to meet these competitive challenges, we will lose market [removed: share to our competitors and experience an overall reduction in our profits.]

[removed: Such legislation] [added: Compliance with more stringent laws] or [removed: restrictions] [added: regulations, as well as more vigorous enforcement policies of the regulatory agencies] could increase the costs of projects for our customers or, in some cases, prevent a project from going forward, which could in turn have an adverse effect on our financial condition and results of operations.

[added: Further, if a] subsidiary location fails to follow the Company’s compliance policies, we could be made party to a contract, arrangement or situation that requires the assumption of large liabilities or has less advantageous terms than is typically found in the market.

[removed: In April 2019, for] example, our information technology infrastructure was impacted by a ransomware attack virus, which caused a substantial majority of our operating locations to experience loss of access to certain data and outages affecting systems including accounting, payroll, billing, job report and management and other software environments.

[added: On the other hand, overutilization of our] workforce could negatively impact safety, employee satisfaction and project execution, leading to a potential decline in future project awards.

[removed: Future] legislation could also have an impact on our business.

Our [removed: 139] [added: 169] locations are located in 27 states, which exposes us to a variety of different state and local laws and regulations, particularly those pertaining to contractor licensing requirements.

[removed: These laws and regulations govern many] aspects of our business, and there are often different standards and requirements in different locations.

Because 5.7% of our revenue for the year ended December 31, [removed: 2020] [added: 2021] was attributable to projects in the government sector, prohibitions against bidding on future government contracts could have an adverse effect on our financial condition and results of operations.

Our failure to comply with these laws and regulations could [added: subject us to substantial fines, the loss of our licenses or potentially debarment from future publicly funded work.]

[removed: It has also] imposed tariffs on certain foreign goods and has raised the possibility of imposing significant, additional tariff increases or expanding the tariffs to capture other types of goods.

[added: Significant judgment] is required in determining our provision for income taxes and our determination of tax liability is always subject to review or examination by tax authorities in applicable tax jurisdictions.

likely to adversely impact our business.

The COVID-19 pandemic and related responses are continuing to evolve and, therefore, continue to present potential risks to our business, particularly in light of new variants of the virus.

The extent of the impact of the COVID-19 pandemic on our business and financial performance, including our ability to execute our near-term and long-term business strategies and initiatives in the expected time frame, depends on numerous evolving factors outside our control including: emergence of new variants of the virus; government, social, business and

other actions that have been and will be taken in response to the COVID-19 pandemic; any additional waves of COVID-19 infections; the efficacy of vaccines on new variants of the virus; the effect of government or customer vaccine or testing requirements on employee retention and recruitment; and the effect of the COVID-19 pandemic on short- and long-term general economic conditions.

share to our competitors and experience an overall reduction in our profits.

Extreme weather conditions (such as storms, droughts, extreme heat or cold, wildfires and floods) may limit the availability of resources,

increase our costs, or may cause projects to be cancelled.

To the extent climate change results in an increase in extreme weather events and adverse weather conditions, the likelihood of a negative impact on our results of operations may increase.

Increasing concerns about climate change and other environmental issues may result in additional environmental regulations and restrictions.

In April 2019, for

In addition, the U.K Financial Conduct Authority, which regulates LIBOR, has announced that, after specified dates, LIBOR settings will cease to be provided by any administrator or will no longer be representative of the underlying market and economic reality that such settings are intended to measure.

Those dates are: (i) June 30, 2023, in the case of the principal U.S. dollar LIBOR tenors (overnight and one, three, six and 12 months); and (ii) December 31, 2021, in all other cases (i.e., one week and two month U.S. dollar LIBOR and all tenors of non-U.S. dollar LIBOR).

Accordingly, many existing LIBOR obligations will transition to another benchmark after June 30, 2023 or, in some cases, after December 31, 2021.

However, those transition dates may occur earlier.

The U. K. Financial Conduct Authority and certain U.S. regulators have encouraged market participants to cease entering into new contracts using U.S. dollar LIBOR by December 31, 2021, despite expected publication of U.S. dollar LIBOR through June 30, 2023.

Regulators have also stated that, for certain purposes, market participants should transition away from U.S. dollar LIBOR sooner.

It is not possible to know what the effect of any such changes in views or alternatives may have on the financial markets for LIBOR-linked financial instruments.

Similar developments have occurred with respect to other IBORs.

Future

On March 2, 2020, the United States Supreme Court granted certiorari to review this case, and on June 17, 2021 the U.S. Supreme Court dismissed a challenge on procedural grounds that argued Affordable Care Act is unconstitutional in its entirety because the “individual mandate” was repealed by Congress.

The Affordable Care Act will remain in effect in its current form; however, we continue to evaluate the effect that the Affordable Care Act has on our business.

These laws and regulations govern many

It has also

In addition, we may acquire companies whose internal controls have design or operational deficiencies, which could impair our ability to integrate those companies into our internal control environment.

The risks and uncertainties described below are not the only ones facing us.

Additional risks and uncertainties not known to us or which we have not determined to be material may also impair our business operations.

The extent of the impact of the COVID-19 pandemic on our business and financial performance, including our ability to execute our near-term and long-term business strategies and initiatives in the expected time frame, will depend on future developments, including the duration and severity of the pandemic, the resulting governmental and other measures implemented to address the pandemic and the development and availability of effective treatments and vaccines, which are uncertain and cannot be predicted at this time.

Further, if a

In addition, in July 2017, the U.K. Financial Conduct Authority, which regulates LIBOR, announced that it intends to stop compelling banks to submit rates for calculation of LIBOR after 2021.

At this time, it is not clear that LIBOR will cease to exist, and if so, what alternative benchmark rate will replace LIBOR, though it is likely that the lenders under our credit agreement would select as an alternative benchmark rate the forward-looking term rate based on the secured overnight financing rate published by the Federal Reserve Bank of New York.

Under the Eurodollar Rate Loan Option under the Facility (defined below), the interest rate is determined based on the one- to six-month Eurodollar Rate, which rate corresponds very closely to rates described in various general business media sources as LIBOR.

Any new benchmark rate will likely not exactly replicate LIBOR, which could impact the determination of interest rates under the Eurodollar Rate Loan Option.

On the other hand, overutilization of our

On March 2, 2020, the United States Supreme Court granted certiorari to review this case, which is expected to be decided by mid-2021.

Because of the continued uncertainty about the implementation of the Affordable Care Act, including the potential for further legal challenges or repeal of that legislation, it is unclear what the impact of the Affordable Care Act, its amendment thereof, or its potential repeal or replacement will have on our financial position or results of operations.

subject us to substantial fines, the loss of our licenses or potentially debarment from future publicly funded work.

Significant judgment

Approximately [removed: 87.0%] [added: 86.7%] of our revenue is earned on a project basis for installation services in newly constructed facilities or for replacement of systems in existing facilities.

[removed: Labor] [added: Accordingly, labor] management and utilization have the most impact on our project performance.

Given the fixed price nature of much of our project work, if our initial estimate of project costs is wrong or we incur cost overruns that cannot be recovered in change orders, we can [added: experience reduced profits or even significant losses on fixed price project work.]

As of December 31, [removed: 2020,] [added: 2021,] we had [removed: 5,687] [added: 7,831] projects in process.

Our average project takes six to nine months to complete, with an average contract price of approximately [removed: $871,000.][added: $802,000.]

Our average project [removed: duration] [added: duration,] together with typical retention terms as discussed [removed: above] [added: above,] generally allow us to complete the realization of revenue and earnings in cash within one year.

Taken together, projects with contract prices of $1 million or more totaled [removed: $4.3] [added: $5.4] billion of aggregate contract value as of December 31, [removed: 2020,] [added: 2021,] or approximately [removed: 85%,] [added: 87%,] out of a total contract value for all projects in progress of [removed: $5.0] [added: $6.3] billion.

A stratification of projects in progress as of December 31, [removed: 2020,] [added: 2021,] by contract price, is as follows:

| $5 million - $10 million | | [removed: 94] [added: 158] | ​ | | [removed: 692.3] [added: 1,084.8] | ​ |

| $10 million - $15 million | | [removed: 56] [added: 53] | ​ | | [removed: 684.9] [added: 661.2] | ​ |

| Greater than $15 million | | [removed: 57] [added: 77] | ​ | | [removed: 1,648.3] [added: 2,167.6] | ​ |

In addition to project work, approximately [removed: 13.0%] [added: 13.3%] of our revenue represents maintenance and repair service on already installed HVAC, electrical, and controls systems.

We manage our [removed: 37] [added: 41] operating units based on a variety of factors.

[added: Operational factors we emphasize include project selection, estimating, pricing, management and execution practices, labor utilization, safety,] training, and the make-up of both existing backlog as well as new business being pursued, in terms of project size, technical application, facility type, end-use customers and industries and location of the work.

With larger amounts of capital, time, and discretion involved, spending decisions are affected to a significant degree by uncertainty, particularly [removed: concerns about economic and financial conditions and trends.]

[removed: During the five-year period from 2015 to 2019, there was an increase in overall activity levels, and then in] [added: In] early [removed: 2020] [added: 2020,] the advent of a global pandemic led to some delays in service and construction, including the potential for delayed project starts and air pockets [removed: as the year ended.][added: during 2020 and early 2021, and we believe those effects are now abating.]

We have a credit facility in [removed: place,] [added: place] with terms we believe are [removed: favorable,] [added: favorable] that does not expire until January 2025.

As of December 31, [removed: 2020,] [added: 2021,] we had [removed: $330.5] [added: $176.5] million of credit available to borrow under our credit facility.

We have generated positive free cash flow in each of the last [removed: twenty-two] [added: twenty-three] calendar years and will continue our emphasis in this area.

We believe that the relative size and strength of our Balance Sheet and surety [removed: relationships] [added: relationships,] as compared to most companies in our [removed: industry] [added: industry,] represent competitive advantages for us.

As discussed at greater length in “Results of Operations” below, we expect price competition to continue as [removed: our customers and] local and regional industry participants compete for customers.

Critical Accounting [removed: Policies][added: Policies and Estimates]

Our critical accounting policies [added: and estimates] are based upon the significance of the accounting policy to our overall financial statement presentation, as well as the complexity of the accounting policy and our use of estimates and subjective assessments.

The customer typically controls the work in [removed: process] [added: process,] as evidenced either by contractual termination clauses or by our rights to payment for work performed to date plus a reasonable profit to deliver products or services that do not have an alternative use to the Company.

For the reasons listed above, revenue is recognized based on the extent of progress towards completion of the performance [removed: obligation.][added: obligation using the percentage of completion method of accounting, which we consider to be a critical accounting estimate.]

The selection of the method to measure progress towards completion requires judgment and is [added: based on the nature of the products or services to be provided.]

[removed: For] [added: In our mechanical segment, for] a small portion of our business in which our services are delivered in the form of service maintenance agreements for existing systems to be repaired and maintained, as opposed to constructed, our performance obligation is to maintain the customer’s mechanical system for a specific period of time.

In addition, we identified other critical accounting policies [added: and estimates] related to [removed: our allowance for credit losses, accounting for leases,] the recording of our self-insurance liabilities, valuation of deferred tax assets, accounting for acquisitions and the recoverability of goodwill and identifiable intangible assets.

These accounting [removed: policies,] [added: policies and estimates,] as well as others, are described in Note 2 to the Consolidated Financial Statements included elsewhere in this annual report on Form 10-K.

Approximately [removed: 87.0%] [added: 86.7%] of our revenue was earned on a project basis and recognized through the percentage of completion method of accounting during [removed: 2020.][added: 2021.]

Purchased equipment on our projects is substantially produced to job [removed: specifications] [added: specifications, normally installed shortly after receipt] and is a value-added element to our work.

We do not currently have any capitalized obtainment or fulfillment costs on our Balance Sheet and [removed: did] [added: have] not [removed: incur] [added: incurred] any impairment loss on such costs in the current year.

The amount of revenue associated with unapproved change orders and claims was immaterial for the year ended December 31, [removed: 2020.][added: 2021.]

Variations from estimated project costs could have a significant impact on our operating results, depending on project size, and the recoverability of the variation [removed: via additional customer payments.][added: from change orders collected from customers.]

We are substantially self-insured for workers’ compensation, employer’s liability, auto liability, general liability and employee group health [removed: claims] [added: claims,] in view of the relatively high per-incident deductibles we absorb under our insurance arrangements for these risks.

Loss estimates associated with the larger and longer-developing [removed: risks—workers’] [added: risks, such as workers’] compensation, auto liability and general [removed: liability—are] [added: liability, are] reviewed by a third-party actuary quarterly.

We have recognized liabilities for these contingent obligations based on their estimated fair value at the date of acquisition with any differences between the acquisition date fair value and the ultimate settlement of the obligations being recognized in income [removed: from operations.][added: in the period of the change.]

_Contingent Assets and Liabilities_—Assets and liabilities arising from contingencies are recognized at their acquisition date fair value when their respective fair values [removed: can be determined.][added: are determinable.]

The market approach utilizes market multiples of invested capital from comparable publicly traded companies [removed: (“public company approach”).]

| ​ | ​ | [removed: 2020] [added: 2021] | | | | | [removed: 2019] [added: 2020] | | | | | [removed: 2018] [added: 2019] | | | | ​ |

| Under $1 million | | 6,864 | ​ | $ | 841.0 | ​ |

| $1 million - $5 million | | 679 | ​ | | 1,527.5 | ​ |

| Total | | 7,831 | ​ | $ | 6,282.1 | ​ |

concerns about economic and financial conditions and trends.

During the five-year period from 2015 to 2019, there was an increase in nonresidential building construction and renovation activity levels.

(“public company approach”).

As described further in Note 6 to the Consolidated Financial Statements, we performed our annual goodwill impairment test during the fourth quarter of 2021.

We determined, after performing a qualitative assessment for each reporting unit except one for which we performed a quantitative assessment, that it is more likely than not that the fair value of each of the reporting units for which we performed a qualitative assessment was substantially greater than its carrying value, and that the fair value of the reporting unit for which we performed a quantitative assessment exceeded the carrying value by 32%.

Accordingly, no further testing was required and no goodwill impairment was recorded for the year ended December 31, 2021.

2021 Compared to 2020

In the first quarter of 2021, we combined two operating locations into one.

Additionally, we completed an immaterial acquisition of a mechanical contractor in Utah, which reports as a separate operating location.

In the fourth quarter of 2021, we completed the acquisitions of Ivey Mechanical Company, LLC (“Ivey”), MEP Holding Co., Inc. (“MEP Holdings”), and a temporary staffing company in Indiana, which all report as separate operating locations.

_Revenue_—Revenue increased $217.0 million, or 7.6%, to $3.07 billion in 2021 compared to 2020.

| ​ | | 2021 | | | | | ​ | 2020 | | | | |

| Mechanical Services | ​ | $ | 2,542,623 | | 82.7 | % | ​ | $ | 2,430,632 | | 85.1 | % |

| Electrical Services | ​ | | 531,013 | | 17.3 | % | ​ | | 426,027 | | 14.9 | % |

Of this increase, $45.0 million resulted from an additional three months of revenue related to the TAS acquisition ($30.0 million) and the Ivey acquisition ($15.0 million), and $67.0 million was attributable to same-store activity.

The increase primarily resulted from the acquisitions of TEC in December 2020 ($92.3 million) and Amteck in August 2021 ($83.5 million), as well as one additional month of revenue ($8.3 million) for our North Carolina electrical contractor.

The following table presents our operating segment backlog (in thousands, except percentages):

| ​ | | 2021 | | | | | ​ | 2020 | | | | |

| Mechanical Services | ​ | $ | 1,753,340 | | 75.8 | % | ​ | $ | 1,267,200 | | 83.8 | % |

| Electrical Services | ​ | | 558,544 | | 24.2 | % | ​ | | 244,214 | | 16.2 | % |

The sequential backlog increase included the Ivey ($108.5 million) and MEP Holdings ($37.7 million) acquisitions.

The sequential same-store backlog increase was primarily a result of increased project bookings at TAS ($132.1 million), our North Carolina operation ($78.5 million) and our Texas electrical operation ($56.7 million).

The sequential backlog increase was partially offset by completion of project work at TEC ($39.5 million).

The year-over-year backlog increase included the acquisitions of Ivey ($108.5 million), Amteck ($76.0 million) and MEP Holdings ($37.7 million), as well as a same-store increase of $578.2 million, or 38.3%.

Same-store year-over-year backlog was broad-based, and increased primarily due to increased project bookings at our North Carolina operation ($146.8 million), our Texas electrical operation ($104.4 million), our Colorado operation ($44.6 million) and TEC ($40.6 million).

*​*

_Gross Profit_—Gross profit increased $16.2 million, or 3.0%, to $563.2 million in 2021 as compared to 2020.

electrical contractor acquisitions, partially offset by a $10.7 million, or 1.9%, decrease on a same-store basis.

As a percentage of revenue, gross profit decreased from 19.1% in 2020 to 18.3% in 2021 primarily due to lower margins at our Arizona and Indiana operations and one of our Florida operations.

Additionally, in the current year, we collected some of these reserve amounts and reduced our assessed risk on collectability as business impacts relating to COVID-19 have stabilized.

Furthermore, tax consulting fees decreased $2.4 million in 2021 as compared to 2020.

| ​ | | 2021 | | | 2020 | | |

| SG&A | ​ | $ | 376,309 | ​ | $ | 357,777 | ​ |

| Same-store SG&A, excluding amortization expense | ​ | $ | 324,650 | ​ | $ | 331,291 | ​ |

This was partially offset by reductions in earn-out obligations at our Utah mechanical contractor and our Indiana operation due to lower than forecasted earnings in the fourth quarter of 2021.

reductions in unrecognized tax benefits plus interest as a result of settlement with the Internal Revenue Service (the “IRS”) upon completion of their examination of our amended federal returns for 2014 and 2015 (4.7%).

Following an IRS survey of our previously filed refund claims for the 2016, 2017 and 2018 tax years, the Joint Committee on Taxation (the “JCT”) approved such refunds in late January 2022.

experience reduced profits or even significant losses on fixed price project work.

| Under $1 million | | 4,905 | ​ | $ | 644.0 | ​ |

| $1 million - $5 million | | 575 | ​ | | 1,283.4 | ​ |

| Total | | 5,687 | ​ | $ | 4,952.9 | ​ |

Operational factors we emphasize include project selection, estimating, pricing, management and execution practices, labor utilization, safety,

Nonresidential building construction and renovation activity, as reported by the federal government, declined steeply over the four-year period from 2009 to 2012, and 2013 and 2014 activity levels were relatively stable at the low levels of the preceding years.

based on the nature of the products or services to be provided.

The costs are considered to be incurred when title is transferred to us, which typically is upon delivery to the work site.

Except in certain circumstances, we do not recognize revenue or margin based on change orders or claims until they have been agreed upon with the customer.

_Accounting for Allowance for Credit Losses_

Effective January 1, 2020, we adopted the requirements of Accounting Standards Update (ASU) No. 2016-13, “Financial Instruments – Credit Losses (Topic 326).” For additional information on the new standard and the impact on our results of operations, refer to our Summary of Significant Accounting Policies in Note 2 to the Consolidated Financial Statements.

We are required to estimate and record the expected credit losses over the contractual life of our financial assets measured at amortized cost, including billed and unbilled accounts receivable, other receivables and costs and estimated earnings in excess of billings.

Accounts receivable include amounts from work completed in which we have billed or have an unconditional right to bill our customers.

Our trade receivables are contractually due in less than a year.

We estimate our credit losses using a loss-rate method for each of our identified portfolio segments.

Our portfolio segments are construction, service and other.

While our construction and service financial assets are often with the same subset of customers and industries, our construction financial assets will generally have a lower loss-rate than service financial assets due to lien rights, which we are more likely to have on construction jobs.

These lien rights result in lower credit loss expenses on average compared to receivables that do not have lien rights.

Financial assets classified as Other include receivables that are not related to our core revenue producing activities, such as receivables related to our acquisition activity from former owners, our vendor rebate program or receivables for estimated losses in excess of our insurance deductible, which are accrued with a corresponding accrued insurance liability.

Loss rates for our portfolios are based on numerous factors, including our history of credit loss expense by portfolio, the financial strength of our customers and counterparties in each portfolio, the aging of our receivables, our expectation of likelihood of payment, macroeconomic trends in the U.S. and the current and forecasted non-residential construction market trends in the U.S.

In addition to the loss-rate calculations discussed above, we also record allowance for credit losses for specific receivables that are deemed to have a higher risk profile than the rest of the respective pool of receivables, such as concerns about a specific customer going bankrupt and no longer being able to pay the receivables due to us.

These estimates are evaluated and adjusted as needed when additional information is received.

_Accounting for Leases_

We lease certain facilities, vehicles and equipment under noncancelable operating leases.

The most significant portion of these noncancelable operating leases are for the facilities occupied by our corporate office and our operating locations.

Leases with an initial term of 12 months or less are not recorded on the Balance Sheet.

We account for lease components separately from the non-lease components.

We have certain leases with variable payments based on an index as well as some short-term leases on equipment and facilities.

Lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term.

As most of our leases do not provide an implicit rate, we generally use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments.

The lease terms generally range from three to ten years.

Some leases include one or more options to renew, which may be exercised to extend the lease term.

We include the exercise of lease renewal options in the lease term when it is reasonably certain that we will exercise the option and such exercise is at our sole discretion.

A majority of the Company’s real property leases are with individuals or entities with whom we have no other business relationship.

However, in certain instances the Company enters into real property leases with current or former employees.

If we decide to cancel or terminate a lease before the end of its term, we would typically owe the lessor the remaining lease payments under the term of the lease.

Our lease agreements do not contain any material residual value guarantees or material restrictive covenants.

On rare occasions, we rent or sublease certain real estate assets that we no longer use to third parties.

In the fourth quarter of 2020, we completed the acquisition of TEC Industrial Construction and Maintenance (“T E C”), which reports as a separate operating location.

_Revenue_—Revenue increased $241.4 million, or 9.2%, to $2.86 billion in 2020 compared to 2019.

We are exposed to market risk primarily related to potential adverse changes in interest [removed: rates] [added: rates,] as discussed below.

We are actively involved in monitoring exposure to market risk and continue to develop and utilize appropriate [removed: risk management techniques.]

We are not exposed to any other significant financial market risks, including commodity price [removed: risk] [added: risk,] or foreign currency exchange [removed: risk,] [added: risk] from the use of derivative financial instruments.

We have exposure to changes in interest rates under our [removed: revolving] [added: senior] credit [removed: facility and term loan.][added: facility.]

The following table presents principal amounts (stated in thousands) and related average interest rates by year of maturity for our debt obligations and their indicated fair market value at December 31, [removed: 2020:][added: 2021:]

| ​ | | [removed: 2021 | | |] 2022 | | | 2023 | | | 2024 | | | 2025 | | | [added: 2026 | | |] Thereafter | | | Total | | |

| Variable Rate Debt | ​ | $ | — | ​ | $ | 15,000 | ​ | $ | [removed: 15,000] [added: 22,500] | ​ | $ | [removed: 22,500] [added: 302,500] | ​ | $ | [removed: 152,500] [added: —] | ​ | $ | — | ​ | $ | [removed: 205,000] [added: 340,000] | ​ |

The weighted average interest rate applicable to the borrowings under the revolving credit facility was approximately 1.4% as of December 31, [removed: 2020.][added: 2021.]

The weighted average interest rate applicable to the term loan was approximately 1.4% as of December 31, [removed: 2020.][added: 2021.]

We did not recognize any [removed: impairments,] [added: impairments] in the current [removed: year,] [added: year] on those assets required to be measured at fair value on a nonrecurring basis.

risk management techniques.

| Fixed Rate Debt | ​ | $ | 2,704 | ​ | $ | 12,900 | ​ | $ | 12,800 | ​ | $ | 19,550 | ​ | $ | — | ​ | $ | — | ​ | $ | 47,954 | ​ |

| Average Interest Rate | ​ | | 2.6% | ​ | | 2.6% | ​ | | 2.5% | ​ | | 2.5% | ​ | | — | ​ | | — | ​ | | 2.5% | ​ |

| Fixed Rate Debt | ​ | $ | — | ​ | $ | 8,000 | ​ | $ | 19,000 | ​ | $ | 4,000 | ​ | $ | — | ​ | $ | — | ​ | $ | 31,000 | ​ |

| Average Interest Rate | ​ | | 3.3% | ​ | | 3.3% | ​ | | 3.0% | ​ | | 3.0% | ​ | | — | ​ | | — | ​ | | 3.1% | ​ |

We build, install, maintain, repair and replace mechanical, electrical and plumbing (“MEP”) systems throughout our [removed: 37] [added: 41] operating units with [removed: 139] [added: 169] locations in [removed: 114] [added: 126] cities throughout the United States.

Substantially all of our consolidated [removed: 2020] [added: 2021] revenue was derived from commercial, industrial and institutional customers and multi-family residential projects.

Approximately [removed: 46.7%] [added: 46.3%] of our revenue was attributable to installation services in newly constructed facilities and [removed: 53.3%] [added: 53.7%] was attributable to renovation, expansion, maintenance, repair and replacement services in existing buildings.

Our consolidated [removed: 2020] [added: 2021] revenue was derived from the following service industries:

| Mechanical Services | | [removed: 84.5] [added: 82.7] | % |

| Electrical Services | ​ | [removed: 15.5] [added: 17.3] | % |

We believe that commercial, industrial, and institutional mechanical and electrical contracting generate annual revenue in the United States of approximately [removed: $200] [added: $300] billion.

| | ● | construction of and installation in new buildings, which provided approximately [removed: 46.7%] [added: 46.3%] of our revenue in [removed: 2020,] [added: 2021,] and |

| | ● | renovation, expansion, maintenance, repair and replacement in existing buildings, which provided the remaining [removed: 53.3%] [added: 53.7%] of our [removed: 2020] [added: 2021] revenue. |

[removed: In order to accomplish our objectives,] [added: Specifically,] we are currently focused on the following elements:

_Achieve Excellence in Core Competencies_—We have identified seven core competencies that we believe are critical to attracting and retaining customers, increasing operating income and cash [removed: flow] [added: flow,] and maximizing the productivity of our [removed: increasingly valuable] skilled labor force.

_Achieve Operating Efficiencies_—We think we can achieve operating efficiencies and cost savings through purchasing economies, adopting [removed: operational] “best practices,” and focusing on [removed: job management to deliver services in a cost-effective and] efficient [removed: manner.][added: job management.]

We are continually improving the “job loop” at our locations—qualifying, estimating, [removed: pricing] [added: pricing,] and executing projects effectively and efficiently.

We also use our combined spend to gain purchasing advantages on products and services such as MEP components, raw materials, services, vehicles, bonding, [removed: insurance] [added: insurance,] and employee benefits.

_Attract, Retain and Invest in our Employees_—We seek to attract and retain quality employees by providing them an enhanced career path that offers a stable income, attractive benefits [removed: packages] [added: packages,] and excellent [removed: advancement] [added: growth] opportunities.

We believe that skilled labor forces in the building and services trades have become increasingly scarce and valuable, and we are [removed: increasing our national and local focus] [added: increasingly focused] on growing and improving our skilled labor force, including through recruitment, [removed: development] [added: development,] and skills training for our hourly workers.

_Focus on Industrial, Commercial and Institutional Markets_—We focus on the industrial, [removed: commercial] [added: commercial,] and institutional building markets, including construction, maintenance, [removed: repair] [added: repair,] and replacement services.

We believe that these complex markets are attractive because of their growth opportunities, large and diverse customer base, attractive [removed: margins] [added: margins,] and potential for long-term relationships with building owners.

We have shifted certain fabrication activities to centralized [added: locations to increase asset utilization.]

[removed: We opportunistically allocate our engineering, field and supervisory labor from] one operation to another to use our employee base more fully, meet our customers’ needs and share expertise.

We believe we have realized scale benefits from coordinated purchasing, technical innovation, insurance, benefits, [removed: bonding] [added: bonding,] and financing activities across our operations.

_Maintain a Diverse Customer, [removed: Geographic] [added: Geographic,] and Project Base_—We have a distribution of revenue across end-use sectors that we believe reduces our exposure to negative developments in any given sector.

Our distribution of revenue in [removed: 2020] [added: 2021] by end-use sector was as follows:

| Office Buildings | | [removed: 11.2] [added: 10.1] | % |

| Retail, Restaurants and Entertainment | | [removed: 8.4] [added: 6.9] | % |

| Multi-Family and Residential | | [removed: 3.0] [added: 3.7] | % |

Approximately [removed: 87.0%] [added: 86.7%] of our revenue is earned on a project basis for installation of systems in newly constructed or existing facilities.

As of December 31, [removed: 2020,] [added: 2021,] we had [removed: 5,687] [added: 7,831] projects in process with an aggregate contract value of approximately [removed: $5.0] [added: $6.3] billion.

Our average project takes six to nine months to complete, with an average contract price of approximately [removed: $871,000.][added: $802,000.]

This average project size, when taken together with the approximately [removed: 13.0%] [added: 13.3%] of our revenue derived from maintenance and service, provides us with a broad base of work in the construction services sector.

A stratification of projects in progress as of December 31, [removed: 2020,] [added: 2021,] by contract price, is as follows:

| $5 million - $10 million | | [removed: 94] [added: 158] | ​ | | [removed: 692.3] [added: 1,084.8] | ​ |

| $10 million - $15 million | | [removed: 56] [added: 53] | ​ | | [removed: 684.9] [added: 661.2] | ​ |

| Greater than $15 million | | [removed: 57] [added: 77] | ​ | | [removed: 1,648.3] [added: 2,167.6] | ​ |

We work to identify, [removed: develop] [added: develop,] and implement new materials, products and methods that can achieve greater productivity and more efficient and sustainable outcomes.

Above all, we have concluded that as technology develops in our industry the fundamental prerequisite for leadership [removed: in] [added: is] adopting such opportunities [removed: is] [added: in] the quality, [removed: accuracy] [added: accuracy,] and buildability of our designs.

Accordingly, we have invested in the experts, training, and internal and external knowledge transfer to ensure that we are properly scaling, achieving true [removed: buildability] [added: buildability,] and fundamentally and continuously improving our design capabilities to meet our customers’ evolving requirements.

Our goal is to use our scale and strategic investments to maintain a leading position in design and modeling excellence, [removed: and we believe that will enable us to] optimize productivity and [removed: quality today,] [added: quality,] and [removed: especially will] [added: ultimately] position [removed: us] [added: ourselves] to [removed: wisely] capitalize from ongoing or future technological developments.

_Construction and Installation Services for New Buildings_—Our installation business related to newly constructed facilities, which comprised approximately [removed: 46.7%] [added: 46.3%] of our consolidated [removed: 2020] [added: 2021] revenue, involves the design, engineering, integration, installation and start-up of MEP and related systems.

We also perform larger project work, with [removed: 782] [added: 967] contracts in progress at December 31, [removed: 2020] [added: 2021] with contract prices in excess of $1 million.

We opportunistically allocate our engineering, field, and supervisory labor from

| Industrial | | 44.1 | % |

| Education | | 12.7 | % |

| Healthcare | | 13.6 | % |

| Other | | 3.2 | % |

| Under $1 million | | 6,864 | ​ | $ | 841.0 | ​ |

| $1 million - $5 million | | 679 | ​ | | 1,527.5 | ​ |

| Total | | 7,831 | ​ | $ | 6,282.1 | ​ |

Our average project takes six to nine months to complete, with an average contract price of approximately $802,000.

The major suppliers of electrical switchgear and generators are Caterpillar, Cummins, Eaton and Schneider Electric.

parties, serve as an extension of the Company.

Climate Change and Sustainability

We recognize our environmental and societal responsibilities and are committed to sustainability and to improving our environmental footprint as well as operating our business in a manner that seeks to protect the health and safety of our employees and customers, as well as the public.

Our focus on environmental stewardship and improving productivity drives not only our efforts to become more energy efficient but also improvements in our customers' impact on climate change.

Replacing an aging building’s existing systems with modern, energy-efficient systems significantly reduces a building’s energy consumption and carbon footprint while improving cost, air quality, and overall system effectiveness.

We are subject to the requirements of numerous federal, state, and local laws, regulations, and rules that promote the protection of the environment.

While capital expenditures or operating costs for environmental compliance cannot be predicted with certainty, we do not currently anticipate that they will have a material effect on our capital expenditures or competitive position in the short term.

Additionally, we plan to increase our voluntary reporting through submissions to CDP (formerly the Carbon Disclosure Project) and the Task Force on Climate-related Financial Disclosures (“TCFD”).

Such additional disclosures are a continuation of our efforts to adhere to voluntary reporting standards – for example, in 2021, we received a bronze medal as a result of our initial EcoVadis submission, and we published our first sustainability report (i) using the Sustainability Accounting Standard Board’s (“SASB”) standards for the Engineering and Construction Services industry, and (ii) in accordance with the Global Reporting Initiative (“GRI”) Standards: Core option.

locations in order to increase asset utilization.

| Industrial | | 38.9 | % |

| Education | | 17.1 | % |

| Healthcare | | 13.0 | % |

| Other | | 2.7 | % |

| Under $1 million | | 4,905 | ​ | $ | 644.0 | ​ |

| $1 million - $5 million | | 575 | ​ | | 1,283.4 | ​ |

| Total | | 5,687 | ​ | $ | 4,952.9 | ​ |

With our recent acquisition of

Starr Electric Company, Incorporated in North Carolina and TAS Energy Inc. in Texas, we significantly improved our off-site construction capabilities and offerings and will continue to invest in the improvement of these offerings.

Although complex modular construction is a small percentage of our current revenue, we believe that it is ripe for investment and growth and that it helps us to sell work and improve outcomes across our businesses.

technicians and communicate with and invoice customers.

respectful; be innovative; and be collaborative.

We are subject to certain [removed: claims] [added: legal] and [added: regulatory claims, including] lawsuits arising in the normal course of business.

While we cannot predict the outcome of these proceedings, in [removed: our] [added: management’s] opinion and based on reports of counsel, any liability arising from these matters individually and in the aggregate will not have a material effect on our operating results, cash flows or financial condition, after giving effect to provisions already recorded.

We are in a dispute with a customer regarding the outcome of a completed project and also regarding the obligation to perform subcontract work under two executed letters of intent for subsequent projects that we believe are not enforceable.

The customer is claiming approximately $12 million in damages related to performance of the original project as well as excess costs to perform the work that was subject to the letters of intent.

We are claiming approximately $9 million composed of unpaid amounts under the completed contract as well as costs and inefficiencies that we suffered.

We have a lien on the project, and this matter is currently scheduled for arbitration in the second quarter of 2022 with a likely decision in the following months.

As of December 31, 2021, we recorded an accrual for this matter based on our analysis of likely outcomes related to this dispute; however, it is possible that the ultimate outcome and associated costs will deviate from our estimates and that, in the event of an unexpectedly adverse outcome, we may experience additional costs and expenses in future periods.

| For the fiscal year ended December [removed: 31, 2020] [added: 31, 2021] | |

The aggregate market value of the voting stock held by non-affiliates of the registrant at June 30, [removed: 2020] [added: 2021] was approximately [removed: $1.45] [added: $2.79] billion, based on the [removed: $40.75] [added: $78.79] last sale price of the registrant’s common stock on the New York Stock Exchange on June 30, [removed: 2020.][added: 2021.]

As of February [removed: 19, 2021, 36,185,179] [added: 18, 2022, 35,956,839] shares of the registrant’s common stock were outstanding (excluding treasury shares of [removed: 4,938,186).][added: 5,166,526).]

The information required by Part III (other than the required information regarding executive officers) is incorporated by reference from the registrant’s definitive proxy statement, which will be filed with the Commission not later than 120 days following December 31, [removed: 2020.][added: 2021.]

| [Item 3.](#ITEM3LegalProceedings_395131) | [Legal Proceedings](#ITEM3LegalProceedings_395131) | [removed: 23] [added: 24] |

| [Item 4.](#ITEM4MineSafetyDisclosures_231930) | [Mine Safety Disclosures](#ITEM4MineSafetyDisclosures_231930) | [removed: 23] [added: 24] |

| [Item 4A.](#ITEM4AExecutiveOfficersoftheRegistrant_3) | [Executive Officers of the Registrant](#ITEM4AExecutiveOfficersoftheRegistrant_3) | [removed: 23] [added: 24] |

| [Item 5.](#ITEM5MarketforRegistrantsCommonEquityRel) | [Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities](#ITEM5MarketforRegistrantsCommonEquityRel) | [removed: 24] [added: 25] |

| [Item 6.](#ITEM6SelectedFinancialData_853719) | [removed: [Selected Financial Data](#ITEM6SelectedFinancialData_853719)] [added: [Reserved](#ITEM6SelectedFinancialData_853719)] | [removed: 26] [added: 27] |

| [Item 7A.](#ITEM7AQuantitativeandQualitativeDisclosu) | [Quantitative and Qualitative Disclosures about Market Risk](#ITEM7AQuantitativeandQualitativeDisclosu) | [removed: 42] [added: 41] |

| [Item 8.](#ITEM8FinancialStatementsandSupplementary) | [Financial Statements and Supplementary Data](#ITEM8FinancialStatementsandSupplementary) | [removed: 44] [added: 43] |

| [Item 9.](#ITEM9ChangesinandDisagreementswithAccoun) | [Changes in and Disagreements with Accountants on Accounting and Financial Disclosure](#ITEM9ChangesinandDisagreementswithAccoun) | [removed: 85] [added: 81] |

| [Item 9A.](#ITEM9AControlsandProcedures_403685) | [Controls and Procedures](#ITEM9AControlsandProcedures_403685) | [removed: 85] [added: 81] |

| [Item 9B.](#ITEM9BOtherInformation_701400) | [Other Information](#ITEM9BOtherInformation_701400) | [removed: 85] [added: 83] |

| [Item 10.](#ITEM10DirectorsExecutiveOfficersandCorpo) | [Directors, Executive Officers and Corporate Governance](#ITEM10DirectorsExecutiveOfficersandCorpo) | [removed: 86] [added: 83] |

| [Item 11.](#ITEMS111213AND14_316091) | [Executive Compensation](#ITEMS111213AND14_316091) | [removed: 86] [added: 83] |

| [Item 12.](#ITEMS111213AND14_316091) | [Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters](#ITEMS111213AND14_316091) | [removed: 86] [added: 83] |

| [Item 13.](#ITEMS111213AND14_316091) | [Certain Relationships and Related Transactions, and Director Independence](#ITEMS111213AND14_316091) | [removed: 86] [added: 83] |

| [Item 14.](#ITEMS111213AND14_316091) | [Principal Accounting Fees and Services](#ITEMS111213AND14_316091) | [removed: 86] [added: 83] |

| [Item 15.](#ITEM15ExhibitsandFinancialStatementSched) | [Exhibits and Financial Statement Schedules](#ITEM15ExhibitsandFinancialStatementSched) | [removed: 86] [added: 83] |

| [Item 16.](#ITEM16Form10KSummary) | [Form 10-K Summary](#ITEM16Form10KSummary) | [removed: 86] [added: 83] |

_Certain statements and information in this Annual Report on Form [removed: 10-K] [added: 10 K] may constitute [removed: forward-looking] [added: forward looking] statements within the meaning of applicable securities laws and regulations.

The words “believe,” “expect,” “anticipate,” “plan,” “intend,” “foresee,” “should,” “would,” “could,” or other similar expressions are intended to identify [removed: forward-looking] [added: forward looking] statements, which are generally not historic in nature.

While the Company’s management believes that these [removed: forward-looking] [added: forward looking] statements are reasonable as and when made, there can be no assurance that future developments affecting the Company will be those that it [removed: anticipates.][added: anticipates, and the Company’s actual results of operations, financial condition and liquidity, and the development of the industry in which the Company operates, may differ materially from those made in or suggested by the forward-looking statements contained in this Annual Report on Form 10 K.]

| [Item 9C.](#ITEM9CDisclosureRegardingForeignJurisdic) | [Disclosure Regarding Foreign Jurisdictions that Prevent Inspections](#ITEM9CDisclosureRegardingForeignJurisdic) | 83 |

In addition, even if our results of operations, financial condition and liquidity, and the development of the industry in which we operate, are consistent with the forward-looking statements contained in this Annual Report on Form 10 K, those results or developments may not be indicative of our results or developments in subsequent periods.

As of December 31, [removed: 2020,] [added: 2021,] we owned [removed: 16] [added: 15] properties.

Lane,_ age [removed: 63,] [added: 64,] has served as our Chief Executive Officer and President since December 2011 and as a director since November 2010.

_William George,_ age [removed: 56,] [added: 57,] has served as our Executive Vice President and Chief Financial Officer since May 2005, was our Senior Vice President, General Counsel and Secretary from May 1998 to May 2005, and was our Vice President, General Counsel and Secretary from March 1997 to April 1998.

Since October 2011, Mr. George has also served as Regional Vice [removed: President for Region 5.][added: President.]

Shaeff,_ age [removed: 55,] [added: 56,] has served as our Senior Vice President and Chief Accounting Officer since May 2005, was our Vice President and Corporate Controller from March 2002 to May 2005, and was our Assistant Corporate Controller from September 1999 to February 2002.

McKenna,_ age [removed: 48,] [added: 49,] has served as Chief Operating Officer and [removed: Senior] [added: Executive] Vice President since January [added: 2022 and was formerly Chief Operating Officer and Senior Vice President during] 2021.

Howell,_ age [removed: 33,] [added: 34,] has served as [added: Senior] Vice President and General Counsel for the Company since January [removed: 2019.][added: 2022 and formerly served as Vice President and General Counsel from January 2019 to December 2021.]

[removed: Prior to her current position,] [added: Previously,] Ms. Howell served as the Associate General Counsel from January 2018 to December 2018 and as Senior Counsel, Corporate from November 2014 to December 2017.

[removed: Young,_] [added: _Terrence Reed_,] age [removed: 58,] [added: 62,] has served as Senior Vice President of [removed: Service] [added: People and Leadership Development] for the Company since [removed: January 2019.][added: March 2021.]

Mr. Reed joined the Company after working in various senior manufacturing and HR leadership positions in several organizations, including Koch Engineered Solutions and Buckeye Technologies.

Mr. Reed is a graduate of the University of South Alabama, where he completed studies in Mechanical Engineering, and is a former US Army officer.

_Terry A.

Prior to his current position, Mr. Young served as a Regional Vice President of Service for the Company from June 2013 to December 2018 and as Director of Business Development from May 2011 to June 2013.

Mr. Young joined the Company after working in various Executive GM and VP positions in Asia Pacific and North American organizations, including Triple M Mechanical, Daikin (formerly McQuay International) and the Trane Company.

He has spent more than 35 years in the commercial HVAC construction and services industry in various roles including technical, engineering, business development, project and strategic activities.

Mr. Young has 6Sigma & PMI certifications and is a graduate of the TAFE College of New South Wales, Australia where he completed studies in F&M Engineering.

As of February [removed: 19, 2021,] [added: 18, 2022,] there were approximately [removed: 319] [added: 301] stockholders of record of our Common Stock, and the last reported sale price on that date was [removed: $60.56] [added: $88.22] per share.

[removed: ][added: ]

As of December 31, [removed: 2020,] [added: 2021,] we have repurchased a cumulative total of [removed: 9.3] [added: 9.7] million shares at an average price of [removed: $19.63] [added: $21.69] per share under the repurchase program.

During the [removed: twelve months] [added: year] ended December 31, [removed: 2020,] [added: 2021,] we repurchased [removed: 0.7] [added: 0.4] million shares for approximately [removed: $30.1] [added: $27.1] million at an average price of [removed: $43.99] [added: $74.57] per share.

During the year ended December 31, [removed: 2020,] [added: 2021,] we purchased our common shares in the following amounts at the following average prices:

| January 1 - January 31 | | 3,000 | ​ | $ | 52.59 | | 9,315,001 | | 978,750 | ​ |

| February 1 - February 28 | | — | ​ | $ | — | | 9,315,001 | | 978,750 | ​ |

| March 1 - March 31 | | 10,250 | ​ | $ | 70.99 | | 9,325,251 | | 968,500 | ​ |

| April 1 - April 30 | | 3,500 | ​ | $ | 75.45 | | 9,328,751 | | 965,000 | ​ |

| May 1 - May 31 | | 8,721 | ​ | $ | 80.49 | | 9,337,472 | | 956,279 | ​ |

| June 1 - June 30 | | 14,871 | ​ | $ | 80.39 | | 9,352,343 | | 941,408 | ​ |

| July 1 - July 31 | | 55,886 | ​ | $ | 75.63 | | 9,408,229 | | 885,522 | ​ |

| August 1 - August 31 | | 111,856 | ​ | $ | 74.91 | | 9,520,085 | | 773,666 | ​ |

| September 1 - September 30 | | 138,380 | ​ | $ | 71.39 | | 9,658,465 | | 635,286 | ​ |

| October 1 - October 31 | | 1,170 | ​ | $ | 71.19 | | 9,659,635 | | 634,116 | ​ |

| November 1 - November 30 | | — | ​ | $ | — | | 9,659,635 | | 634,116 | ​ |

| December 1 - December 31 | | 15,162 | ​ | $ | 94.93 | | 9,674,797 | | 618,954 | ​ |

| ​ | | 362,796 | ​ | $ | 74.57 | | 9,674,797 | | 618,954 | ​ |

| January 1 - January 31 | | 26,606 | ​ | $ | 49.04 | | 8,653,973 | | 894,196 | ​ |

| February 1 - February 29 | | 17,724 | ​ | $ | 47.58 | | 8,671,697 | | 876,472 | ​ |

| March 1 - March 31 | | 193,029 | ​ | $ | 35.42 | | 8,864,726 | | 683,443 | ​ |

| April 1 - April 30 | | — | ​ | $ | — | | 8,864,726 | | 683,443 | ​ |

| May 1 - May 31 | | 3,000 | ​ | $ | 36.72 | | 8,867,726 | | 680,443 | ​ |

| June 1 - June 30 | | 49,991 | ​ | $ | 38.22 | | 8,917,717 | | 630,452 | ​ |

| July 1 - July 31 | | 24,455 | ​ | $ | 39.22 | | 8,942,172 | | 605,997 | ​ |

| August 1 - August 31 | | 23,966 | ​ | $ | 51.00 | | 8,966,138 | | 582,031 | ​ |

| September 1 - September 30 | | 109,387 | ​ | $ | 51.10 | | 9,075,525 | | 472,644 | ​ |

| October 1 - October 31 | | 37,442 | ​ | $ | 46.62 | | 9,112,967 | | 435,202 | ​ |

| November 1 - November 30 | | 166,325 | ​ | $ | 47.63 | | 9,279,292 | | 268,877 | ​ |

| December 1 - December 31 | | 32,709 | ​ | $ | 51.21 | | 9,312,001 | | 981,750 | ​ |

| ​ | | 684,634 | ​ | $ | 43.99 | | 9,312,001 | | 981,750 | ​ |

The following selected historical financial data has been derived from our audited financial statements and should be read in conjunction with the historical Consolidated Financial Statements and related notes:

| ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| ​ | | Year Ended December 31, | | | | | | | | | | | | | | ​ |

| ​ | | 2020 | | | 2019 | | | 2018 | | | 2017 | | | 2016 | | ​ |

| | | | | | | | | | | | | | | | | |

| ​ | | (in thousands, except per share amounts) | | | | | | | | | | | | | | ​ |

| STATEMENT OF OPERATIONS DATA: | | ​ | | | ​ | | | ​ | | | ​ | | | ​ | | ​ |

| Revenue | ​ | $ | 2,856,659 | ​ | $ | 2,615,277 | ​ | $ | 2,182,879 | ​ | $ | 1,787,922 | ​ | $ | 1,634,340 | ​ |

| Operating income (1) | ​ | $ | 190,651 | ​ | $ | 163,639 | ​ | $ | 150,238 | ​ | $ | 99,260 | ​ | $ | 101,569 | ​ |

| Net income | ​ | $ | 150,139 | ​ | $ | 114,324 | ​ | $ | 112,903 | ​ | $ | 55,272 | ​ | $ | 64,896 | ​ |

| Basic income per share from continuing operations | ​ | $ | 4.11 | ​ | $ | 3.10 | ​ | $ | 3.03 | ​ | $ | 1.48 | ​ | $ | 1.74 | ​ |

| Diluted income per share from continuing operations | ​ | $ | 4.09 | ​ | $ | 3.08 | ​ | $ | 3.00 | ​ | $ | 1.47 | ​ | $ | 1.72 | ​ |

| Cash dividends per share | ​ | $ | 0.425 | ​ | $ | 0.395 | ​ | $ | 0.330 | ​ | $ | 0.295 | ​ | $ | 0.275 | ​ |

| BALANCE SHEET DATA: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ |

| Working capital | ​ | $ | 118,948 | ​ | $ | 182,187 | ​ | $ | 142,642 | ​ | $ | 115,629 | ​ | $ | 98,276 | ​ |

| Total assets (2) | ​ | $ | 1,757,355 | ​ | $ | 1,505,012 | ​ | $ | 1,062,564 | ​ | $ | 881,120 | ​ | $ | 708,903 | ​ |

| Total debt, net | ​ | $ | 235,733 | ​ | $ | 226,135 | ​ | $ | 76,918 | ​ | $ | 60,539 | ​ | $ | 2,811 | ​ |

| Total stockholders’ equity | ​ | $ | 696,429 | ​ | $ | 585,304 | ​ | $ | 498,047 | ​ | $ | 417,945 | ​ | $ | 376,633 | ​ |

| | (1) | Included in operating income is a goodwill impairment charge of $1.1 million for 2017. There were no goodwill impairment charges for 2020, 2019, 2018 or 2016. |

| --- | --- | --- |

| | (2) | The impact of adoption of the new lease accounting standard is reflected in total assets in 2019. |

| [Report of Independent Registered Public Accounting Firm](#ReportofIndependentRegisteredPublicAccou) [added: (PCAOB ID No. 34)] | ​ | [removed: 46] [added: 44] |

| [Report of Independent Registered Public Accounting [removed: Firm](#RegisteredPublicAccountingFirm_299282)] [added: Firm](#ReportofIndependentRegisteredEY) (PCAOB ID No. 42)] | ​ | [removed: 48] [added: 46] |

| [Consolidated Balance Sheets](#CONSOLIDATEDBALANCESHEETS_522126) | ​ | [removed: 49] [added: 47] |

| [Consolidated Statements of Operations](#CONSOLIDATEDSTATEMENTSOFOPERATIONS_39514) | ​ | [removed: 50] [added: 48] |

| [Consolidated Statements of Stockholders’ Equity](#STATEMENTSOFSTOCKHOLDERSEQUITY_511143) | ​ | [removed: 51] [added: 49] |

| [Consolidated Statements of Cash Flows](#STATEMENTSOFCASHFLOWS_915327) | ​ | [removed: 52] [added: 50] |

| [Notes to Consolidated Financial Statements](#NOTESTOCONSOLIDATEDFINANCIALSTATEMENTS_6) | ​ | [removed: 53] [added: 51] |

We have audited the accompanying consolidated balance [removed: sheets] [added: sheet] of Comfort Systems USA, Inc. (the Company) as of December 31, [removed: 2020 and 2019,] [added: 2020,] the related consolidated statements of operations, stockholders’ equity and cash flows for each of the [removed: three] [added: two] years in the period ended December 31, 2020, and the related notes (collectively referred to as the “consolidated financial statements”).

In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, [removed: 2020 and 2019,] [added: 2020,] and the results of its operations and its cash flows for each of the [removed: three] [added: two] years in the period ended December 31, 2020, in conformity with U.S. generally accepted accounting principles.

We [removed: also] have [added: also] audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, [removed: 2020,] [added: 2021,] based on criteria established in _Internal Control-Integrated Framework_ [added: _(2013)_] issued by the Committee of Sponsoring Organizations of the Treadway Commission [removed: (2013 framework),] and our report dated February [removed: 25, 2021] [added: 23, 2022,] expressed an unqualified opinion [removed: thereon.][added: on the Company’s internal control over financial reporting.]

The critical audit matter communicated below [removed: was] [added: is] a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and [removed: that:] [added: that] (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, [removed: subjective] [added: subjective,] or complex judgments.

The communication of [removed: the] critical audit [removed: matter] [added: matters] does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing [added: a] separate [removed: opinions] [added: opinion] on the critical audit matter or on the accounts or disclosures to which it relates.

We have served as the Company’s auditor since [removed: 2002.][added: 2021.]

February 25, [removed: 2021][added: 2021,]

Our responsibility is to express an opinion on the Company’s [removed: internal control over] financial [removed: reporting] [added: statements] based on our [removed: audit.][added: audits.]

Those standards require that we plan and perform the audit to obtain reasonable assurance about whether [removed: effective internal control over] [added: the] financial [removed: reporting was maintained in all] [added: statements are free of] material [removed: respects.][added: misstatement, whether due to error or fraud.]

| ​ | | [added: | 2021 | | |] 2020 | | | 2019 | | [removed: ​] |

| Cash and cash equivalents | ​ | $ | [removed: 54,896] [added: 58,776] | ​ | $ | [removed: 50,788] [added: 54,896] | ​ |

| Billed accounts receivable, less allowance for credit losses of [removed: $9,087] [added: $8,808] and [removed: $6,907,] [added: $9,087,] respectively | ​ | | [removed: 619,544] [added: 773,716] | ​ | | [removed: 619,037] [added: 619,544] | ​ |

| Unbilled accounts receivable, less allowance for credit losses of [removed: $784] [added: $715] and [removed: $0,] [added: $784,] respectively | ​ | | [removed: 45,596] [added: 61,881] | ​ | | [removed: 55,542] [added: 45,596] | ​ |

| Other receivables, less allowance for credit losses of [removed: $759] [added: $503] and [removed: $0,] [added: $759,] respectively | ​ | | [removed: 44,212] [added: 57,491] | ​ | | [removed: 37,632] [added: 44,212] | ​ |

| Inventories | ​ | | [removed: 13,472] [added: 21,853] | ​ | | [removed: 10,053] [added: 13,472] | ​ |

| Prepaid expenses and other | ​ | | [removed: 15,510] [added: 23,704] | ​ | | [removed: 14,396] [added: 15,510] | ​ |

| Costs and estimated earnings in excess of billings, less allowance for credit losses of [removed: $79] [added: $84] and [removed: $0,] [added: $79,] respectively | ​ | | [removed: 18,622] [added: 29,900] | ​ | | [removed: 2,736] [added: 18,622] | ​ |

| Total current assets | ​ | | [removed: 811,852] [added: 1,027,321] | ​ | | [removed: 790,184] [added: 811,852] | ​ |

| PROPERTY AND EQUIPMENT, NET | ​ | | [removed: 117,206] [added: 128,554] | ​ | | [removed: 109,796] [added: 117,206] | ​ |

| LEASE RIGHT-OF-USE ASSET | ​ | ​ | [removed: 94,727] [added: 124,756] | ​ | ​ | [removed: 84,073] [added: 94,727] | ​ |

| GOODWILL | ​ | | [removed: 464,392] [added: 592,114] | ​ | | [removed: 332,447] [added: 464,392] | ​ |

| IDENTIFIABLE INTANGIBLE ASSETS, NET | ​ | | [removed: 231,807] [added: 304,781] | ​ | | [removed: 159,974] [added: 231,807] | ​ |

| DEFERRED TAX ASSETS | ​ | ​ | [removed: 29,401] [added: 22,905] | ​ | ​ | [removed: 21,923] [added: 29,401] | ​ |

| OTHER NONCURRENT ASSETS | ​ | | [removed: 7,970] [added: 8,683] | ​ | | [removed: 6,615] [added: 7,970] | ​ |

| Total assets | ​ | $ | [removed: 1,757,355] [added: 2,209,114] | ​ | $ | [removed: 1,505,012] [added: 1,757,355] | ​ |

| Current maturities of long-term debt | ​ | $ | [removed: —] [added: 2,788] | ​ | $ | [removed: 20,817] [added: —] | ​ |

| Accounts payable | ​ | | [removed: 204,145] [added: 254,788] | ​ | | [removed: 196,195] [added: 204,145] | ​ |

| Accrued compensation and benefits | ​ | | [removed: 121,864] [added: 129,971] | ​ | | [removed: 102,891] [added: 121,864] | ​ |

| Billings in excess of costs and estimated earnings | ​ | | [removed: 226,237] [added: 307,380] | ​ | | [removed: 166,918] [added: 226,237] | ​ |

| Accrued self-insurance | ​ | | [removed: 49,166] [added: 22,227] | ​ | | [removed: 39,546] [added: 49,166] | ​ |

| Other current liabilities | ​ | | [removed: 91,492] [added: 119,400] | ​ | | [removed: 81,630] [added: 91,492] | ​ |

| Total current liabilities | ​ | | [removed: 692,904] [added: 836,554] | ​ | | [removed: 607,997] [added: 692,904] | ​ |

| LONG-TERM DEBT, NET | ​ | | [removed: 235,733] [added: 385,242] | ​ | | [removed: 205,318] [added: 235,733] | ​ |

| ​ HIDDEN_ROW | | |

We have audited the accompanying consolidated balance sheet of Comfort Systems USA, Inc. and subsidiaries (the “Company”) as of December 31, 2021, the related consolidated statements of operations, stockholders’ equity and cash flows, for the year ended December 31, 2021, and the related notes (collectively referred to as the “consolidated financial statements”).

In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2021, and the results of its operations and its cash flows for the year ended December 31, 2021, in conformity with accounting principles generally accepted in the United States of America.

Our audit included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks.

Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements.

Revenue from Contracts with Customers – Refer to Notes 2 and 3 to the consolidated financial statements

_Critical Audit Matter Description_

The Company recognizes revenue based on the extent of progress towards completion of the performance obligation.

The Company generally uses the cost to cost measure of progress for its contracts, as it depicts the transfer of assets to the customer that occurs as the Company incurs costs, which include labor, materials, subcontractors’ costs, other direct costs, and an allocation of indirect costs.

Due to the nature of the work required to be performed on many of the performance obligations, the estimation of costs at completion is complex, subject to many variables and requires considerable judgment.

Given the judgments necessary to account for the Company’s contracts with customers, specifically the use of estimates, such as total costs to be incurred at contract completion, which are complex and subject to many variables, auditing the corresponding balances and related accounting estimates required extensive audit effort due to the complexity of these estimates, and a high degree of auditor judgment when performing audit procedures and evaluating the results of those procedures.

_How the Critical_ _Audit Matter was Addressed in the Audit_

Our audit procedures related to management’s estimates and judgments included within the Company’s estimated total costs at completion, included the following, among others:

| ● | We tested the operating effectiveness of controls over the recognition of revenue, including those over the determination of estimated costs at completion of the contracts (including the estimated progress toward completion). |

| ● | We evaluated quarter over quarter changes in contract profit estimates for a selection of contracts by obtaining explanations from Company’s management regarding timing and amount and corroborating these inquiries by inspecting documents, including management work plans, customer communications, change orders, vendor invoices, and supplier or subcontractor communications. |

| ● | We developed an independent expectation of recorded revenue at certain operating units using analytical procedures and considering relevant current and historical information and compared our expectations to the recorded revenue for the operating unit. |

| --- | --- |

| ● | For a sample of contracts with customers, we performed the following: |

| --- | --- |

| | o | Evaluated the reasonableness of management’s estimates of total costs and profit at completion for selected contracts with customers by: |

| | ◾ | Evaluating management’s ability to estimate total costs at completion for each selected contract by performing corroborating inquiries with the Company’s project managers and personnel involved with the selected contracts, and comparing the estimates to management’s work plans, suppliers’ contracts, and/or engineering specifications. |

| | ◾ | Comparing management’s estimates to supporting documents such as purchase orders, subcontract agreements, third-party invoices from suppliers, historical actual results, and other sources, as applicable. |

| | ◾ | Evaluating management’s ability to accurately estimate total costs and profits at completion by comparing actual costs and profits to management’s historical estimates for performance obligations that have been fulfilled. |

| | ◾ | Evaluating changes in estimates and obtaining evidence on timing and amounts supporting these changes in estimates such as approved change order documents, communications with the customer, subcontract agreements and related amendments, recent actual costs, and other sources. |

/s/ Deloitte & Touche LLP

February 23, 2022

Opinion on the Financial Statements

These financial statements are the responsibility of the Company's management.

Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements.

We served as the Company’s auditor from 2002 to 2021.

except for Note 16, as to which the date is

February 23, 2022

| Net income | ​ | — | ​ | ​ | — | ​ | — | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 143,348 | ​ | ​ | 143,348 | ​ |

| Issuance of shares for options exercised | ​ | — | ​ | ​ | — | ​ | 195,724 | ​ | ​ | 5,399 | ​ | ​ | 235 | ​ | ​ | — | ​ | ​ | 5,634 | ​ |

| Issuance of restricted stock & performance stock | ​ | — | ​ | ​ | — | ​ | 101,360 | ​ | ​ | 2,681 | ​ | ​ | (473) | ​ | ​ | — | ​ | ​ | 2,208 | ​ |

| Dividends ($0.48 per share) | ​ | — | ​ | ​ | — | ​ | — | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (17,384) | ​ | ​ | (17,384) | ​ |

| Share repurchase | ​ | — | ​ | ​ | — | ​ | (362,796) | ​ | ​ | (27,054) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | (27,054) | ​ |

| BALANCE AT DECEMBER 31, 2021 | ​ | 41,123,365 | ​ | $ | 411 | ​ | (5,032,311) | ​ | $ | (150,580) | ​ | $ | 327,061 | ​ | $ | 628,774 | ​ | $ | 805,666 | ​ |

| Payments on finance lease liabilities | ​ | ​ | (3,805) | ​ | | — | ​ | ​ | — | ​ |

_Recently Adopted Accounting Pronouncements_

| ​ | | |

| [Management’s Report on Internal Control over Financial Reporting](#ManagementsReportonInternalControloverFi) | ​ | 45 |

Management’s Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f).

Under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting as of December 31, 2020 based on the framework in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO 2013 framework).

Based on that evaluation, our management concluded that our internal control over financial reporting was effective as of December 31, 2020.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Ernst & Young LLP, an independent registered public accounting firm, as stated in their report which is included elsewhere herein, has issued an attestation report auditing the effectiveness of our internal control over financial reporting as of December 31, 2020.

​

| ​ | ​ ​ |

| ​ | Revenue recognition using percentage of completion method ​ |

| _Description of the Matter_ | As disclosed in Note 3 to the consolidated financial statements, for fixed price agreements, the Company uses the percentage of completion (POC) method of accounting under which contract revenue recognizable at any time during the life of a contract is determined by multiplying expected total contract revenue by the percentage of contract costs incurred at any time to total estimated contract costs. Estimating contract costs is subjective and certain projects require considerable judgment and could be impacted by changes in labor and materials/equipment. ​ |

| | Auditing management’s estimates of total contract costs for certain longer-duration projects was challenging due to significant judgments made by management with respect to labor and materials/equipment costs as future results may vary significantly from past estimates due to changes in facts and circumstances as the project progresses to completion. ​ |

| _How We Addressed the Matter in Our Audit_ | We obtained an understanding, evaluated the design, and tested the operating effectiveness of controls over the contract estimated cost at completion process. For example, we tested controls over management’s review of cost estimates for significant inputs such as labor and materials/equipment costs. ​ To evaluate the Company’s contract cost estimates, our audit procedures included selecting a sample of contracts and, among others procedures, reviewing the contracts and any associated amendments, conducting interviews with and reviewing questionnaires completed by project personnel, assessing blended labor rates used in the estimate to complete the project against blended labor rates actually incurred to date, agreeing estimated labor and materials/equipment costs to supporting documentation, and performing lookback analyses comparing gross margin over the life of the project to assess management’s ability to estimate. ​ |

/s/ Ernst & Young LLP

Opinion on Internal Control over Financial Reporting

We have audited Comfort Systems USA, Inc.’s internal control over financial reporting as of December 31, 2020, based on criteria established in _Internal Control—Integrated Framework_ issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework) (the COSO criteria).

In our opinion, Comfort Systems USA, Inc. (the Company) maintained, in all material respects, effective internal control over financial reporting as of December 31, 2020, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated balance sheets of the Company as of December 31, 2020 and 2019, the related consolidated statements of operations, stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2020, and the related notes and our report dated February 25, 2021 expressed an unqualified opinion thereon.

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting included in the accompanying Management’s Report on Internal Control over Financial Reporting.

Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances.

Definition and Limitations of Internal Control Over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles.

A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

| ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ |

| --- | --- | --- | --- | --- | --- | --- | --- |

| ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| DIVIDENDS PER SHARE | ​ | ​ | $ | 0.425 | ​ | $ | 0.395 | ​ | $ | 0.330 | ​ |

| BALANCE AT DECEMBER 31, 2017 | | 41,123,365 | ​ | $ | 411 | | (3,936,291) | ​ | $ | (63,519) | ​ | $ | 312,784 | ​ | $ | 168,269 | | $ | 417,945 | ​ |

| Net income | | — | ​ | | — | | — | ​ | | — | ​ | | — | ​ | | 112,903 | | | 112,903 | ​ |

| Issuance of shares for options exercised | | — | ​ | | — | | 206,875 | ​ | | 3,618 | ​ | | (513) | ​ | | — | | | 3,105 | ​ |

| Issuance of restricted stock & performance stock | | — | ​ | | — | | 129,569 | ​ | | 2,227 | ​ | | (4) | ​ | | — | | | 2,223 | ​ |

| Dividends | | — | ​ | | — | | — | ​ | | — | ​ | | — | ​ | | (12,268) | | | (12,268) | ​ |

| Share repurchase | | — | ​ | | — | | (592,839) | ​ | | (28,533) | ​ | | — | ​ | | — | | | (28,533) | ​ |

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326).” The standard requires companies to consider historical experiences, current market conditions and reasonable and supportable forecasts in the measurement of expected credit losses.

The standard requires us to accrue higher credit losses on financial assets compared to the legacy guidance on various items, such as contract assets and current receivables.

We adopted ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326),” on January 1, 2020,

The adoption of ASU No. 2016-13 resulted in an increase in Allowance for Credit Losses of $0.7 million, an increase to Deferred Tax Assets of $0.2 million and an impact of $0.5 million to Retained Earnings.

Based [removed: upon] [added: on] that evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) of the Securities Exchange Act of 1934) are effective as of the end of the period covered by this report.

[removed: Internal Controls] [added: Opinion on Internal Control] over Financial Reporting

[removed: Management’s report] [added: Management’s Report] on [removed: our internal controls] [added: Internal Control] over [removed: financial reporting can be found in Item 8 of this report.][added: Financial Reporting]

There have not been any changes in our internal control over financial reporting (as such term is defined in Rules [removed: 13a-15(f)] [added: 13a 15(f)] and [removed: 15d-15(f)] [added: 15d 15(f)] under the Securities Exchange Act of 1934) during the three months ended December 31, [removed: 2020] [added: 2021] that [removed: has] [added: have] materially affected, or are reasonably likely to materially affect, internal control over financial reporting.

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f).

Under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting as of December 31, 2021 based on the framework in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO 2013 framework).

Based on that evaluation, our management concluded that our internal control over financial reporting was effective as of December 31, 2021.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

The Company acquired Amteck Holdco LLC (“Amteck”) in August 2021 and Ivey Mechanical Company, LLC (“Ivey”), MEP Holding Co., Inc. (“MEP Holdings”), Thermal Equipment Service, Inc. and TES Controls, LLC (collectively “Thermal”) and Kodiak Labor Solutions, LLC (“Kodiak”) in December 2021.

Due to the recent nature of these business combinations, Amteck, Ivey, MEP Holdings, Thermal and Kodiak’s internal control over financial reporting and related processes have not been fully integrated into the Company’s existing systems and internal control over financial reporting as of December 31, 2021.

As such, our management has excluded Amteck, Ivey, MEP Holdings, Thermal and Kodiak from its assessment of the effectiveness of internal control over financial reporting as of December 31, 2021.

Collectively, Amteck, Ivey, MEP Holdings, Thermal and Kodiak comprised 18.3% of total assets and 3.2% of revenues in our consolidated financial statements as of and for the year ended December 31, 2021.

Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report which is included elsewhere herein, has issued an attestation report auditing the effectiveness of our internal control over financial reporting as of December 31, 2021.

​

Report of Independent Registered Public Accounting Firm

​

To the stockholders and the Board of Directors of Comfort Systems USA, Inc.

​

​

We have audited the internal control over financial reporting of Comfort Systems USA, Inc. and subsidiaries (the “Company”) as of December 31, 2021, based on criteria established in _Internal Control — Integrated Framework (2013)_ issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2021, based on criteria established in _Internal Control — Integrated Framework (2013)_ issued by COSO.

​

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated financial statements for the year ended December 31, 2021, of the Company and our report dated February 23, 2022, expressed an unqualified opinion on those financial statements.

As described in Management’s Report on Internal Control over Financial Reporting, management excluded from its assessment the internal control over financial reporting at Amteck Holdco LLC (acquired August 1, 2021), Ivey Mechanical Company, LLC (acquired December 1, 2021), MEP Holding Co., Inc., Thermal Equipment Service, Inc. and TES Controls, LLC, and Kodiak Labor Solutions, LLC (each acquired December 31, 2021), and whose financial statements collectively constitute 18.3% of total assets and 3.2% of total revenues in the consolidated financial statement amounts as of and for the year ended December 31, 2021.

Accordingly, our audit did not include the internal control over financial reporting at Amteck Holdco LLC, Ivey Mechanical Company, LLC, MEP Holding Co., Inc., Thermal Equipment Service, Inc. and TES Controls, LLC, and Kodiak Labor Solutions, LLC.

​

Basis for Opinion

​

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control over Financial Reporting.

Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit.

We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

​

We conducted our audit in accordance with the standards of the PCAOB.

Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects.

​

Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances.

We believe that our audit provides a reasonable basis for our opinion.

​

Definition and Limitations of Internal Control over Financial Reporting

​

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles.

A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

​

The Independent Registered Public Accounting Firm’s Attestation Report on the effectiveness of our internal controls over financial reporting can also be found in Item 8 of this report.

PART III

Not applicable.

PART III

The Company will file with the Commission a definitive proxy statement including the other information to be disclosed under this item in the 120 days following December 31, [removed: 2020] [added: 2021] and such information is hereby incorporated by reference.

The Company will file with the Commission a definitive proxy statement including the information to be disclosed under the items in the 120 days following December 31, [removed: 2020] [added: 2021] and such information is hereby incorporated by reference.

| ​ | ​ | ​ | ​ | Incorporated by [removed: Reference to] [added: Referenceto] the Exhibit Indicated [removed: Below and] [added: Belowand] to the Filing with [removed: the Commission] [added: theCommission] Indicated Below | | |

| [removed: Exhibit Number] [added: ExhibitNumber] | | Description of Exhibits | | [removed: Exhibit Number] [added: ExhibitNumber] | | Filing or File Number |

| [removed: *10.5] [added: *10.8] | ​ | [Form of Option Award under the Comfort Systems USA, Inc. [removed: 2006] [added: 2012] Equity Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000110465907015093/a07-5471_1ex10d6.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746915001294/a2223211zex-10_33.htm)] | ​ | [removed: 10.6] [added: 10.33] | ​ | [removed: 2006] [added: 2014] Form 10-K |

| [removed: *10.7] [added: *10.1] | ​ | [Employment Agreement between the Company, Eastern Heating & Cooling, Inc. and Alfred J. Giardinelli, Jr.](http://www.sec.gov/Archives/edgar/data/1035983/000095012903003918/h07903exv10w1.txt) | ​ | 10.1 | ​ | Second Quarter 2003 Form 10-Q |

| [removed: *10.9] [added: *10.18] | ​ | [removed: [2008] [added: [2017] Senior Management Annual Performance [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746908004478/a2184426zdef14a.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002563/fix-20170523xdef14a.htm)] | ​ | B | ​ | [removed: Proxy Statement] April 10, [removed: 2008] [added: 2017 Proxy Statement] |

| [removed: *10.10] [added: *10.2] | ​ | [Form of [removed: Change in Control Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000104746908005698/a2185250zex-10_2.htm)] [added: Comfort Systems USA, Inc. Executive Severance Policy](http://www.sec.gov/Archives/edgar/data/1035983/000104746908005698/a2185250zex-10_3.htm)] | ​ | [removed: 10.2] [added: 10.3] | ​ | First Quarter 2008 Form 10-Q |

| [removed: *10.12] [added: *10.3] | ​ | [Form of Directors and Officers Indemnification Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465909033654/a09-12567_2ex10d1.htm) | ​ | 10.1 | ​ | May 19, 2009 Form 8-K |

| [removed: 10.13] [added: 10.4] | ​ | [Second Amended and Restated Credit Agreement by and among Comfort Systems USA, Inc., as Borrower and Wells Fargo Bank, National Association, as Administrative Agent/Wells Fargo Securities LLC, as Sole Lead Arranger and Sole Lead Book Runner/Bank of Texas, N.A., Capital One, N.A., and Regions Bank as Co-Syndication Agent/and Certain Financial Institutions as Lenders](http://www.sec.gov/Archives/edgar/data/1035983/000110465910039133/a10-14233_1ex10d1.htm) | ​ | 10.1 | ​ | July 22, 2010 Form 8-K/A |

| [removed: 10.14] [added: 10.5] | ​ | [Stock Purchase Agreement, dated July 28, 2010](http://www.sec.gov/Archives/edgar/data/1035983/000110465910040867/a10-14873_1ex10d1.htm) | ​ | 10.1 | ​ | July 30, 2010 Form 8-K |

| [removed: 10.18] [added: 10.6] | ​ | [Amendment No. 1 to Second Amended and Restated Credit Agreement, Second Amended and Restated Security Agreement, and Second Amended and Restated Pledge Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000104746911009144/a2206146zex-10_1.htm) | ​ | 10.1 | ​ | Third Quarter 2011 Form 10-Q |

| *10.19 | ​ | [removed: [Summary] [added: [Form] of [added: Restricted Stock Unit Agreement under the Company’s] 2012 [added: Equity] Incentive [removed: Compensation Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746912005259/a2209092zex-10_1.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex102e9479d.htm)] | ​ | [removed: 10.1] [added: 10.2] | ​ | First Quarter [removed: 2012] [added: 2017] Form 10-Q |

| *10.21 | ​ | [Form of [removed: 2012] Dollar-denominated Performance [removed: Vesting] Restricted Stock Unit [removed: Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465912022874/a12-8439_1ex10d2.htm)] [added: Agreement under the Company’s 2012 Equity Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex104628293.htm)] | ​ | [removed: 10.2] [added: 10.4] | ​ | [removed: March 30, 2012] [added: First Quarter 2017] Form [removed: 8-K] [added: 10-Q] |

| [removed: *10.22] [added: *10.17] | ​ | [removed: [2012 Equity] [added: [2017 Omnibus] Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746912004050/a2208641zdef14a.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002563/fix-20170523xdef14a.htm)] | ​ | A | ​ | April [removed: 9, 2012] [added: 10, 2017] Proxy Statement |

| [removed: 10.27] [added: 10.7] | ​ | [Amendment No. 2 to Second Amended and Restated Credit Agreement and Amendment to Other Loan Documents](http://www.sec.gov/Archives/edgar/data/1035983/000104746913007932/a2216107zex-10_1.htm) | ​ | 10.1 | ​ | Second Quarter 2013 Form 10-Q |

| [removed: *10.28] [added: *10.14] | ​ | [removed: [Letter] [added: [Resignation and General Release] Agreement between the Company and James [removed: Mylett](http://www.sec.gov/Archives/edgar/data/1035983/000104746914001513/a2218454zex-10_28.htm)] [added: Mylett, dated as of January 10, 2017](http://www.sec.gov/Archives/edgar/data/1035983/000110465917001957/a17-1811_1ex10d1.htm)] | ​ | [removed: 10.28] [added: 10.1] | ​ | [removed: 2013] [added: January 11, 2017] Form [removed: 10-K] [added: 8-K] |

| [removed: *10.29] [added: *10.11] | ​ | [Form of [added: Amended] Change in Control [removed: Agreement (2013)](http://www.sec.gov/Archives/edgar/data/1035983/000104746914001513/a2218454zex-10_29.htm)] [added: Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000104746915008149/a2226337zex-10_1.htm)] | ​ | [removed: 10.29] [added: 10.1] | ​ | [removed: 2013] [added: Third Quarter 2015] Form [removed: 10-K] [added: 10-Q] |

| [removed: *10.33] [added: *10.20] | ​ | [Form of [added: Stock] Option [removed: Award] [added: Notice] under the [removed: Comfort Systems USA, Inc.] [added: Company’s] 2012 Equity Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746915001294/a2223211zex-10_33.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex103bc199c.htm)] | ​ | [removed: 10.33] [added: 10.3] | ​ | [removed: 2014] [added: First Quarter 2017] Form [removed: 10-K] [added: 10-Q] |

| [removed: 10.34] [added: 10.9] | ​ | [Amendment No. 3 to Second Amended and Restated Credit Agreement and Amendment to Other Loan Documents](http://www.sec.gov/Archives/edgar/data/1035983/000104746914008664/a2221896zex-10_1.htm) | ​ | 10.1 | ​ | Third Quarter 2014 Form 10-Q |

| [removed: 10.35] [added: 10.10] | ​ | [Agreement and Plan of Merger between the Company and Dyna Ten Corporation, dated April 9, 2014](http://www.sec.gov/Archives/edgar/data/1035983/000110465914026747/a14-10230_1ex10d1.htm) | ​ | 10.1 | ​ | April 9, 2014 Form 8-K |

| [removed: 10.40] [added: 10.12] | ​ | [Amendment No. 4 to Second Amended and Restated Credit Agreement and Amendment to Other Loan Documents](http://www.sec.gov/Archives/edgar/data/1035983/000104746916010332/a2227387zex-10_40.htm) | ​ | 10.40 | ​ | 2015 Form 10-K |

| [removed: *10.41] [added: *10.13] | ​ | [Form of 2016 [removed: Restricted] Stock [removed: Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465916107645/a16-7178_1ex10d1.htm)] [added: Option Notice](http://www.sec.gov/Archives/edgar/data/1035983/000110465916107645/a16-7178_1ex10d3.htm)] | ​ | [removed: 10.1] [added: 10.3] | ​ | March 25, 2016 Form 8-K |

| [removed: 10.45] [added: 10.15] | ​ | [Stock Purchase Agreement, dated February 21, 2017, by and among the Company, BCH, the Selling Shareholders and Daryl Blume, in his capacity as representative of the Selling Shareholders](http://www.sec.gov/Archives/edgar/data/1035983/000110465917011244/a17-7023_1ex2d1.htm) | ​ | 2.1 | ​ | February 23, 2017 Form 8-K |

| [removed: 10.46] [added: 10.16] | ​ | [Form of Promissory Note, dated April 1, 2017, issued by the Company in favor of each of the Selling Shareholders](http://www.sec.gov/Archives/edgar/data/1035983/000110465917020991/a17-10800_1ex10d1.htm) | ​ | 10.1 | ​ | April 3, 2017 Form 8-K |

| [removed: *10.49] [added: *10.22] | ​ | [Form of Restricted Stock Unit Agreement under the Company’s [removed: 2012 Equity] [added: 2017 Omnibus] Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex102e9479d.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex101c8a191.htm)] | ​ | [removed: 10.2] [added: 10.1] | ​ | First Quarter [removed: 2017] [added: 2018] Form 10-Q |

| [removed: *10.50] [added: *10.23] | ​ | [Form of Stock Option Notice under the Company’s [removed: 2012 Equity] [added: 2017 Omnibus] Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex103bc199c.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex102ce3cf4.htm)] | ​ | [removed: 10.3] [added: 10.2] | ​ | First Quarter [removed: 2017] [added: 2018] Form 10-Q |

| [removed: *10.51] [added: *10.24] | ​ | [Form of Dollar-denominated Performance Restricted Stock Unit Agreement under the Company’s [removed: 2012 Equity] [added: 2017 Omnibus] Incentive [removed: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002931/fix-20170331ex104628293.htm)] [added: Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex10323834b.htm)] | ​ | [removed: 10.4] [added: 10.3] | ​ | First Quarter [removed: 2017] [added: 2018] Form 10-Q |

| [removed: 10.55] [added: 10.25] | ​ | [Amendment No. 5 to Second Amended and Restated Credit Agreement and Amendment to Other Loan Documents](http://www.sec.gov/Archives/edgar/data/1035983/000155837018005771/fix-20180630ex1010b4b06.htm) | ​ | 10.1 | ​ | Second Quarter 2018 Form 10-Q |

| [removed: 10.56] [added: 10.26] | ​ | [Purchase Agreement, dated February 21, 2019, by and among the Company, Walker, the Shareholder Sellers and Scott Walker, in his capacity as representative of the Shareholder Sellers](https://www.sec.gov/Archives/edgar/data/1035983/000110465919010746/a19-5185_2ex2d1.htm) | ​ | 2.1 | ​ | February 26, 2019 Form 8-K |

| [removed: 10.57] [added: 10.27] | ​ | [Amendment No. 6 to Second Amended and Restated Credit Agreement and Amendment to Other Loan Documents](https://www.sec.gov/Archives/edgar/data/1035983/000155837020001491/ex-10d56.htm) | ​ | 10.56 | ​ | 2019 Form 10-K |

| [removed: 10.58] [added: 10.28] | ​ | [Agreement and Plan of Merger dated as of March 9, 2020 among Comfort Systems USA, Inc., OSC Acquisition Corp., TAS Energy Inc., and Element Partners II, L.P., as Stockholder Representative](https://www.sec.gov/Archives/edgar/data/1035983/000110465920033252/tm2012107d1_ex2-1.htm) | ​ | 2.1 | ​ | March 13, 2020 Form 8-K |

| 21.1 | ​ | [List of subsidiaries of Comfort Systems USA, [removed: Inc.](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex21d1.htm)] [added: Inc.](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex21d1.htm)] | ​ | ​ | ​ | Filed Herewith |

| [removed: 23.1] [added: 23.2] | ​ | [Consent of Ernst & Young [removed: LLP](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex23d1.htm)] [added: LLP](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex23d2.htm)] | ​ | ​ | ​ | Filed Herewith |

| 31.1 | ​ | [Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of [removed: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex31d1.htm)] [added: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex31d1.htm)] | ​ | ​ | ​ | Filed Herewith |

| 31.2 | ​ | [Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of [removed: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex31d2.htm)] [added: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex31d2.htm)] | ​ | ​ | ​ | Filed Herewith |

| 32.1 | ​ | [Certification of Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of [removed: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex32d1.htm)] [added: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex32d1.htm)] | ​ | ​ | ​ | Furnished Herewith |

| 32.2 | ​ | [Certification of Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of [removed: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837021001828/fix-20201231xex32d2.htm)] [added: 2002](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex32d2.htm)] | ​ | ​ | ​ | Furnished Herewith |

| Date: February [removed: 25, 2021] [added: 23, 2022] | ​ | ​ |

| /s/ Brian E. Lane | ​ | President, Chief Executive Officer, and | ​ | February [removed: 25, 2021] [added: 23, 2022] | ​ |

| /s/ William George | ​ | Executive Vice President and Chief Financial | ​ | February [removed: 25, 2021] [added: 23, 2022] | ​ |

| /s/ Julie S. Shaeff | ​ | Senior Vice President and Chief Accounting | ​ | February [removed: 25, 2021] [added: 23, 2022] | ​ |

| ​ | ​ | ​ | ​ | Incorporated by Referenceto the Exhibit Indicated Belowand to the Filing with theCommission Indicated Below | | |

| ExhibitNumber | | Description of Exhibits | | ExhibitNumber | | Filing or File Number |

| 16.1 | ​ | [Letter to Securities and Exchange Commission from Ernst & Young LLP, dated March 15, 2021](https://www.sec.gov/Archives/edgar/data/0001035983/000110465921036255/tm219577d1_ex16-1.htm) | ​ | 16.1 | ​ | March 15, 2021 Form 8-K |

| 23.1 | ​ | [Consent of Deloitte & Touche LLP](https://www.sec.gov/Archives/edgar/data/1035983/000155837022001753/fix-20211231xex23d1.htm) | ​ | ​ | ​ | Filed Herewith |

| ​ | ​ | ​ | ​ | Incorporated by Referenceto the Exhibit Indicated Belowand to the Filing with theCommission Indicated Below | | |

| ExhibitNumber | | Description of Exhibits | | ExhibitNumber | | Filing or File Number |

| /s/ Cindy L. Wallis-Lage | ​ | Director | ​ | February 23, 2022 | ​ |

| Cindy L. Wallis-Lage | ​ | ​ | ​ | ​ | ​ |

| | | | | | | |

| --- | --- | --- | --- | --- | --- | --- |

| *10.1 | ​ | [Comfort Systems USA, Inc. 1997 Long-Term Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/0000890566-97-000536-index.html) | ​ | 10.1 | ​ | 333-24021 |

| *10.2 | ​ | [Comfort Systems USA, Inc. 1997 Non-Employee Directors’ Stock Plan](http://www.sec.gov/Archives/edgar/data/1035983/0000890566-97-000536-index.html) | ​ | 10.2 | ​ | 333-24021 |

| *10.3 | ​ | [Amendment to the 1997 Non-Employee Directors’ Stock Plan dated May 23, 2002](http://www.sec.gov/Archives/edgar/data/1035983/000095012902004151/h98970aexv10w3.txt) | ​ | 10.3 | ​ | Second Quarter 2002 Form 10-Q/A |

| *10.4 | ​ | [Comfort Systems USA, Inc. 2006 Equity Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000110465906070563/a06-18678_1ex4d5.htm) | ​ | 4.5 | ​ | 333-138377 |

| *10.6 | ​ | [Form of Option Award under the Comfort Systems USA, Inc. 2006 Stock Options/SAR Plan for Non-Employee Directors](http://www.sec.gov/Archives/edgar/data/1035983/000110465907015093/a07-5471_1ex10d7.htm) | ​ | 10.7 | ​ | 2006 Form 10-K |

| *10.8 | ​ | [Amended and Restated 2006 Equity Compensation Plan for Non-Employee Directors](http://www.sec.gov/Archives/edgar/data/1035983/000104746908004478/a2184426zdef14a.htm) | ​ | A | ​ | Proxy Statement April 10, 2008 |

| *10.11 | ​ | [Form of Comfort Systems USA, Inc. Executive Severance Policy](http://www.sec.gov/Archives/edgar/data/1035983/000104746908005698/a2185250zex-10_3.htm) | ​ | 10.3 | ​ | First Quarter 2008 Form 10-Q |

| *10.15 | ​ | [Summary of 2011 Incentive Compensation Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746911004482/a2203822zex-10_1.htm) | ​ | 10.1 | ​ | First Quarter 2011 Form 10-Q |

| *10.16 | ​ | [Form of Performance Restricted Stock Award Agreement dated March 24, 2011](http://www.sec.gov/Archives/edgar/data/1035983/000110465911017163/a11-8794_1ex10d1.htm) | ​ | 10.1 | ​ | March 28, 2011 Form 8-K |

| *10.17 | ​ | [First Amendment to Comfort Systems USA, Inc. Amended and Restated 2006 Equity Compensation Plan for Non-Employee Directors](http://www.sec.gov/Archives/edgar/data/1035983/000104746911006852/a2205014zex-10_1.htm) | ​ | 10.1 | ​ | Second Quarter 2011 Form 10-Q |

| *10.20 | ​ | [Form of 2012 Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465912022874/a12-8439_1ex10d1.htm) | ​ | 10.1 | ​ | March 30, 2012 Form 8-K |

| *10.23 | ​ | [2012 Senior Management Annual Performance Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746912004050/a2208641zdef14a.htm) | ​ | B | ​ | April 9, 2012 Proxy Statement |

| *10.24 | ​ | [Summary of 2013 Incentive Compensation Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746913005255/a2214704zex-10_1.htm) | ​ | 10.1 | ​ | First Quarter 2013 Form 10-Q |

| *10.25 | ​ | [Form of 2013 Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465913023637/a13-7992_1ex10d1.htm) | ​ | 10.1 | ​ | March 22, 2013 Form 8-K |

| *10.26 | ​ | [Form of 2013 Dollar-denominated Performance Vesting Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465913023637/a13-7992_1ex10d2.htm) | ​ | 10.2 | ​ | March 22, 2013 Form 8-K |

| *10.30 | ​ | [Summary of 2014 Incentive Compensation Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746914004448/a2219822zex-10_1.htm) | ​ | 10.1 | ​ | First Quarter 2014 Form 10-Q |

| *10.31 | ​ | [Form of 2014 Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465914021851/a14-8658_1ex10d1.htm) | ​ | 10.1 | ​ | March 21, 2014 Form 8-K |

| *10.32 | ​ | [Form of 2014 Dollar-denominated Performance Vesting Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465914021851/a14-8658_1ex10d2.htm) | ​ | 10.2 | ​ | March 21, 2014 Form 8-K |

| *10.36 | ​ | [Form of 2015 Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465915025173/a15-8489_1ex10d1.htm) | ​ | 10.1 | ​ | April 1, 2015 Form 8-K |

| *10.37 | ​ | [Form of 2015 Dollar-denominated Performance Vesting Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465915025173/a15-8489_1ex10d2.htm) | ​ | 10.2 | ​ | April 1, 2015 Form 8-K |

| *10.38 | ​ | [Summary of 2015 Incentive Compensation Plan](http://www.sec.gov/Archives/edgar/data/1035983/000104746915004125/a2224431zex-10_1.htm) | ​ | 10.1 | ​ | First Quarter 2015 Form 10-Q |

| *10.39 | ​ | [Form of Amended Change in Control Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000104746915008149/a2226337zex-10_1.htm) | ​ | 10.1 | ​ | Third Quarter 2015 Form 10-Q |

| *10.42 | ​ | [Form of 2016 Dollar-denominated Performance Restricted Stock Unit Agreement](http://www.sec.gov/Archives/edgar/data/1035983/000110465916107645/a16-7178_1ex10d2.htm) | ​ | 10.2 | ​ | March 25, 2016 Form 8-K |

| *10.43 | ​ | [Form of 2016 Stock Option Notice](http://www.sec.gov/Archives/edgar/data/1035983/000110465916107645/a16-7178_1ex10d3.htm) | ​ | 10.3 | ​ | March 25, 2016 Form 8-K |

| *10.44 | ​ | [Resignation and General Release Agreement between the Company and James Mylett, dated as of January 10, 2017](http://www.sec.gov/Archives/edgar/data/1035983/000110465917001957/a17-1811_1ex10d1.htm) | ​ | 10.1 | ​ | January 11, 2017 Form 8-K |

| *10.47 | ​ | [2017 Omnibus Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002563/fix-20170523xdef14a.htm) | ​ | A | ​ | April 10, 2017 Proxy Statement |

| *10.48 | ​ | [2017 Senior Management Annual Performance Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837017002563/fix-20170523xdef14a.htm) | ​ | B | ​ | April 10, 2017 Proxy Statement |

| *10.52 | ​ | [Form of Restricted Stock Unit Agreement under the Company’s 2017 Omnibus Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex101c8a191.htm) | ​ | 10.1 | ​ | First Quarter 2018 Form 10-Q |

| *10.53 | ​ | [Form of Stock Option Notice under the Company’s 2017 Omnibus Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex102ce3cf4.htm) | ​ | 10.2 | ​ | First Quarter 2018 Form 10-Q |

| *10.54 | ​ | [Form of Dollar-denominated Performance Restricted Stock Unit Agreement under the Company’s 2017 Omnibus Incentive Plan](http://www.sec.gov/Archives/edgar/data/1035983/000155837018003336/fix-20180331ex10323834b.htm) | ​ | 10.3 | ​ | First Quarter 2018 Form 10-Q |

| /s/ James H. Schultz | ​ | Director | ​ | February 25, 2021 | ​ |

| James H. Schultz | ​ | ​ | ​ | ​ | ​ |