Item 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

The following section updates "Item 7A. Quantitative and Qualitative Disclosures About Market Risk" in the 2022 Form 10-K and should be read in conjunction with that report as well as our condensed consolidated financial statements.

Interest Rate Risk

Our interest rate risk as of June 30, 2023 relates primarily to the impact of interest rate movements on the following, after giving effect to the repayment of our 3.150% Senior Notes utilizing proceeds from our 2016 Revolver:

• our $2.7 billion of floating rate debt as of June 30, 2023, which represented approximately 12% of our total debt as of June 30, 2023; and

• potential future borrowings of incremental debt, including borrowings under our 2016 Credit Facility and issuances under our CP Program.

Since March 2022, the Federal Reserve has repeatedly raised the federal funds rate for a cumulative increase of 5.25%. Further increases in the federal funds rate could increase our costs of borrowing. See also "Item 1A. Risk Factors" in the 2022 Form 10-K for a discussion of risks stemming from interest rate increases.

We currently have no interest rate swaps.

Sensitivity Analysis. We manage our exposure to market interest rates on our existing debt by controlling the mix of fixed and floating rate debt. As of June 30, 2023, after giving effect to the repayment of our 3.150% Senior Notes, we had 2.7 billion of floating rate debt. As a result, a hypothetical unfavorable fluctuation in market interest rates on our existing debt of 1/4 of a percent point over a 12-month period would increase our interest expense by approximately $7 million.

Future Principal Payments and Interest Rates. The following table provides information about our market risk related to changes in interest rates. The future principal payments and weighted-average interest rates are presented as of June 30, 2023, after giving effect to the repayment of our 3.150% Senior Notes. These debt maturities reflect final maturity dates and do not consider the impact of the principal payments that commence following the anticipated repayment dates of certain debt (see footnotes (b) and (d)). The information presented below regarding the variable rate debt is supplementary to our sensitivity analysis regarding the impact of changes in the interest rates. See notes 4 and 5 to our condensed consolidated financial statements and the 2022 Form 10-K for additional information regarding our debt.

(a)The fair value of our debt is based on indicative quotes, non-binding quotes from brokers that require judgment to interpret market information, including implied credit spreads for similar borrowings on recent trades or bid/ask offers. These fair values are not necessarily indicative of the amount, which could be realized in a current market exchange.

(b)The impact of principal payments that will commence following the anticipated repayment dates is not considered (see footnote (d) below). The Tower Revenue Notes, Series 2015-2 and Series 2018-2 have principal amounts of $700 million and $750 million, with anticipated repayment dates in 2025 and 2028, respectively.

(c)The average interest rate represents the weighted-average stated coupon rate (see footnote (d) below).

(d)If the Tower Revenue Notes are not repaid in full by the applicable anticipated repayment dates, the applicable interest rate increases by approximately 5% per annum and monthly principal payments commence using the Excess Cash Flow (as defined in the indenture governing the applicable Tower Revenue Notes) of the issuers of the Tower Revenue Notes. The Tower Revenue Notes are presented based on their contractual maturity dates ranging from 2045 to 2048 and include the impact of an assumed 5% increase in interest rate that would occur following the anticipated repayment dates but exclude the impact of monthly principal payments that would commence using Excess Cash Flow of the issuers of the Tower Revenue Notes. The full year 2022 Excess Cash Flow of the issuers of the Tower Revenue Notes was approximately $1.0 billion. We currently expect to refinance these notes on or prior to the respective anticipated repayment dates.

(e)See note 7 to our consolidated financial statements in the 2022 Form 10-K for information regarding potential upward or downward adjustments to the interest rate spread and unused commitment fee percentage on our 2016 Credit Facility if we achieve specified annual sustainability targets or fail to meet annual sustainability metrics. Each period presented assumes the downward adjustments in the interest rate spread and unused commitment fee percentage on our 2016 Credit Facility.

(f)Predominately consists of outstanding indebtedness under our CP Program. Such amounts may be issued, repaid or re-issued from time to time.