Item 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS (continued)

NISOURCE INC.

Other Information

Critical Accounting Policies

NiSource applies certain accounting policies based on the accounting requirements discussed below that have had, and may continue to have, significant impacts on NiSource’s results of operations and Consolidated Financial Statements.

Basis of Accounting for Rate-Regulated Subsidiaries. ASC Topic 980, Regulated Operations, provides that rate-regulated subsidiaries account for and report assets and liabilities consistent with the economic effect of the way in which regulators establish rates, if the rates established are designed to recover the costs of providing the regulated service and if the competitive environment makes it probable that such rates can be charged and collected. Certain expenses and credits subject to utility regulation or rate determination normally reflected in income are deferred on the Consolidated Balance Sheets and are recognized in income as the related amounts are included in service rates and recovered from or refunded to customers. The total amounts of regulatory assets and liabilities reflected on the Consolidated Balance Sheets were $1,801.2 million and $2,795.6 million at December 31, 2017, and $1,885.4 million and $1,381.8 million at December 31, 2016, respectively. For additional information, refer to Note 8, “Regulatory Matters,” in the Notes to Consolidated Financial Statements.

In the event that regulation significantly changes the opportunity for NiSource to recover its costs in the future, all or a portion of NiSource’s regulated operations may no longer meet the criteria for the application of ASC Topic 980, Regulated Operations. In such event, a write-down of all or a portion of NiSource’s existing regulatory assets and liabilities could result. If transition cost recovery is approved by the appropriate regulatory bodies that would meet the requirements under GAAP for continued accounting as regulatory assets and liabilities during such recovery period, the regulatory assets and liabilities would be reported at the recoverable amounts. If unable to continue to apply the provisions of ASC Topic 980, Regulated Operations, NiSource would be required to apply the provisions of ASC Topic 980-20, Discontinuation of Rate-Regulated Accounting. In management’s opinion, NiSource’s regulated subsidiaries will be subject to ASC Topic 980, Regulated Operations for the foreseeable future.

Certain of the regulatory assets reflected on NiSource’s Consolidated Balance Sheets require specific regulatory action in order to be included in future service rates. Although recovery of these amounts is not guaranteed, NiSource believes that these costs meet the requirements for deferral as regulatory assets. Regulatory assets requiring specific regulatory action amounted to $398.4 million at December 31, 2017. If NiSource determined that the amounts included as regulatory assets were not recoverable, a charge to income would immediately be required to the extent of the unrecoverable amounts.

The passage of the TCJA into law necessitated the remeasurement of NiSource’s deferred income tax balances to reflect the new U.S. corporate income tax rate of 21%. For NiSource’s regulated entities, substantially all of the impact of this remeasurement was recorded to a regulatory asset or regulatory liability, as appropriate, until such time that NiSource receives final regulatory orders prescribing the required accounting treatment and related impact on future customer rates. To the extent final regulatory orders received prescribe accounting treatment different from what is currently reflected in NiSource’s financial statements, NiSource’s results of operations could be impacted.

Pension and Postretirement Benefits. NiSource has defined benefit plans for both pension and other postretirement benefits. The calculation of the net obligations and annual expense related to the plans requires a significant degree of judgment regarding the discount rates to be used in bringing the liabilities to present value, expected long-term rates of return on plan assets, health care trend rates, and mortality rates, among other assumptions. Due to the size of the plans and the long-term nature of the associated liabilities, changes in the assumptions used in the actuarial estimates could have material impacts on the measurement of the net obligations and annual expense recognition. Differences between actuarial assumptions and actual plan results are deferred into AOCI or a regulatory balance sheet account, depending on the jurisdiction of the NiSource entity. These deferred gains or losses are then amortized into the income statement when the accumulated differences exceed 10% of the greater of the projected benefit obligation or the fair value of plan assets (known in GAAP as the “corridor” method) or when settlement accounting is triggered.

The discount rates, expected long-term rates of return on plan assets, health care cost trend rates and mortality rates are critical assumptions. Methods used to develop these assumptions are described below. While a third party actuarial firm assists with the development of many of these assumptions, NiSource is ultimately responsible for selecting the final assumptions.

The discount rate is utilized principally in calculating the actuarial present value of pension and other postretirement benefit obligations and net periodic pension and other postretirement benefit plan costs. NiSource’s discount rates for both pension and other postretirement benefits are determined using spot rates along an AA-rated above median yield curve with cash flows matching the expected duration of benefit payments to be made to plan participants.

The expected long-term rate of return on plan assets is a component utilized in calculating annual pension and other postretirement

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS (continued)

NISOURCE INC.

benefit plan costs. NiSource estimates the expected return on plan assets by evaluating expected bond returns, equity risk premiums, target asset allocations, the effects of active plan management, the impact of periodic plan asset rebalancing and historical performance. NiSource also considers the guidance from its investment advisors in making a final determination of its expected rate of return on assets.

For measurement of 2018 net periodic benefit cost, NiSource selected an expected pre-tax long-term rate of return of 7.00% and 5.80% for its pension and other postretirement benefit plan assets, respectively.

NiSource estimates the assumed health care cost trend rate, which is used in determining the Company's other postretirement benefit net expense, based upon its actual health care cost experience, the effects of recently enacted legislation, third-party actuarial surveys and general economic conditions.

NiSource uses the Society of Actuaries’ most recently published mortality data in developing a best estimate of mortality as part of the calculation of the pension and other postretirement benefit obligations.

The following tables illustrate the effects of changes in these actuarial assumptions while holding all other assumptions constant:

(1)Before labor capitalization and regulatory deferrals.

In January 2017, NiSource changed the method used to estimate the service and interest components of net periodic benefit cost for pension and other postretirement benefits. This change, compared to the previous method, resulted in a decrease in the actuarially-determined service and interest cost components. Historically, NiSource estimated service and interest cost utilizing a single weighted-average discount rate derived from the yield curve used to measure the benefit obligation at the beginning of the period. For fiscal 2017 and beyond, NiSource now utilizes a full yield curve approach to estimate these components by applying the specific spot rates along the yield curve used in the determination of the benefit obligation to the relevant projected cash flows. For further discussion of NiSource’s pension and other postretirement benefits, see Note 11, “Pension and Other Postretirement Benefits,” in the Notes to Consolidated Financial Statements.

Goodwill. NiSource has seven goodwill reporting units, comprised of the seven state operating companies within the Gas Distribution Operations reportable segment. NiSource’s goodwill assets at December 31, 2017 were $1,690.7 million, most of which resulted from the acquisition of Columbia on November 1, 2000.

As required by GAAP, NiSource tests for impairment of goodwill on an annual basis and on an interim basis when events or circumstances indicate that a potential impairment may exist. NiSource’s annual goodwill test takes place in the second quarter of each year and was most recently finalized as of May 1, 2017.

NiSource completed a quantitative ("step 1") fair value measurement of its reporting units during the May 1, 2016 goodwill test.

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS (continued)

NISOURCE INC.

Consistent with NiSource’s historical impairment testing of goodwill, fair value of the reporting units was determined based on a weighting of income and market approaches. These approaches require significant judgments including appropriate long-term growth rates and discount rates for the income approach and appropriate multiples of earnings for peer companies and control premiums for the market approach. A qualitative ("step 0") test was completed on May 1, 2017. NiSource assessed various assumptions, events and circumstances that would have affected the estimated fair value of the reporting units in its baseline May 1, 2016 test. The results of this assessment indicated that it is not more likely than not that its reporting unit fair values are less than the reporting unit carrying values and no impairments are necessary.

The discount rates were derived using peer company data compiled with the assistance of a third party valuation services firm. The discount rates used are subject to change based on changes in tax rates at both the state and federal level, debt and equity ratios at each reporting unit and general economic conditions.

The long-term growth rate was derived by evaluating historic growth rates, new business and investment opportunities beyond the near term horizon. The long-term growth rate is subject to change depending on inflationary impacts to the U.S. economy and the individual business environments in which each reporting unit operates.

The May 1, 2016 test indicated the fair value of each of the reporting units that carry or are allocated goodwill exceeded their carrying values, indicating that no impairment existed under the step 1 annual impairment test. If the estimates of free cash flow used in this step 1 analysis had been 10% lower, the resulting fair values would have still been greater than the carrying value for each of the reporting units tested, holding all other assumptions constant.

Revenue Recognition. Revenue is recorded as products and services are delivered. Utility revenues are billed to customers monthly on a cycle basis. Revenues are recorded on the accrual basis and include estimates for electricity and gas delivered but not billed. Refer to Note 1-I, “Revenue Recognition,” in the Notes to Consolidated Financial Statements.

NiSource adopted the provisions of ASC 606 beginning on January 1, 2018 using a modified retrospective method, which was applied to all contracts. No material adjustments were made to January 1, 2018 opening balances as a result of the adoption and NiSource does not anticipate material changes in the amount or timing of future revenue recognition as a result of the adoption of ASC 606.

Recently Issued Accounting Pronouncements

Refer to Note 2, "Recent Accounting Pronouncements," in the Notes to Consolidated Financial Statements.