Item 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

The following section updates "Item 7A. Quantitative and Qualitative Disclosures About Market Risk" in the 2020 Form 10-K and should be read in conjunction with that report as well as our condensed consolidated financial statements included in Part 1, Item 1 of this Form 10-Q.

Interest Rate Risk

Our interest rate risk as of September 30, 2021 relates primarily to the impact of interest rate movements on the following:

• the potential refinancing of our existing debt ($20.5 billion outstanding at September 30, 2021 and $19.4 billion at December 31, 2020);

• our $1.9 billion and $2.8 billion of floating rate debt at September 30, 2021 and December 31, 2020, respectively, which represented approximately 9% and 15% of our total debt, as of September 30, 2021 and December 31, 2020, respectively; and

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

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 September 30, 2021, we had $1.9 billion of floating rate debt, none of which had LIBOR floors. As a result, a hypothetical unfavorable fluctuation in market interest rates on our existing debt of 1/8 of a percent point over a 12 month period would increase our interest expense by approximately $2 million.

Tabular Information

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 September 30, 2021. 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 2020 Form 10-K for additional information regarding our debt.

(a)The fair value of our debt is based on indicative quotes (that is, 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. The Tower Revenue Notes have principal amounts of $250 million, $700 million and $750 million, with anticipated repayment dates in 2023, 2025 and 2028, respectively.

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

(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 2043 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 2020 Excess Cash Flow of the issuers of the Tower Revenue Notes was approximately $815 million. We currently expect to refinance these notes on or prior to the respective anticipated repayment dates.

(e)Predominately relates to our 2016 Term Loan A and 2016 Revolver borrowings, each of which matures in 2026.

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