In June 2023, the stockholders of the Company approved the T-Mobile US, Inc. 2023 Incentive Award Plan (the “2023 Plan”) which replaced the 2013 Omnibus Incentive Plan and the Sprint Corporation Amended and Restated 2015 Omnibus Incentive Plan that T-Mobile assumed in connection with the closing of the Merger (collectively, with the 2023 Plan, the “Incentive Plans”). Under the 2023 Plan, we are authorized to issue up to 33 million shares of our common stock and can grant stock options, stock appreciation rights, restricted stock, RSUs and PRSUs to eligible employees, consultants, advisors and non-employee directors. As of December 31, 2023, there were approximately 33 million shares of common stock available for future grants under the 2023 Plan.

We grant RSUs to eligible employees, key executives and certain non-employee directors and PRSUs to eligible key executives. RSUs entitle the grantee to receive shares of our common stock upon vesting (with vesting generally occurring annually over a three-year service period), subject to continued service through the applicable vesting date. PRSUs entitle the holder to receive shares of our common stock at the end of a performance period of generally up to three years if the applicable performance goals are achieved and generally subject to continued service through the applicable performance period. The number of shares ultimately received by the holder of PRSUs is dependent on our business performance against the specified performance goal(s) over a pre-established performance period. We also maintain an employee stock purchase plan (“ESPP”), under which eligible employees can purchase our common stock at a discounted price.

Stock-based compensation expense and related income tax benefits were as follows:


	As of and for the Year Ended December 31,
(in millions, except shares, per share and contractual life amounts)		2023		2022		2021
Stock-based compensation expense		$	667	$	596	$	540
Income tax benefit related to stock-based compensation		$	130	$	114	$	100
Weighted-average fair value per stock award granted		$	143.09	$	126.89	$	116.11
Unrecognized compensation expense		$	637	$	635	$	625
Weighted-average period to be recognized (years)		1.8		1.8		1.8
Fair value of stock awards vested		$	889	$	743	$	944

Time-Based Restricted Stock Units


(in millions, except shares, per share and contractual life amounts)	Number of Units or Awards	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value

Nonvested, December 31, 2022	8,373,059	$	121.09	0.9	$	1,172

Granted	5,288,829	145.73
Vested	(4,760,872)	118.99
Forfeited	(1,145,073)	138.10

Nonvested, December 31, 2023	7,755,943	136.67		0.9	1,244

Performance-Based Restricted Stock Units


(in millions, except shares, per share and contractual life amounts)	Number of Units or Awards	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value

Nonvested, December 31, 2022	1,360,783	$	124.09	0.8	$	191

Granted	232,094	157.61
Performance award achievement adjustments (1)	579,306	113.20
Vested	(1,384,895)	114.57
Forfeited	(14,639)	159.06
Other adjustments	(82,843)	118.00

Nonvested, December 31, 2023	689,806	145.32		1.0	111

(1)Represents PRSUs granted prior to 2023 for which the performance achievement period was completed in 2023, resulting in incremental unit awards. These PRSU awards are also included in the amount vested in 2023.

PRSUs included in the table above are shown at target. Share payout can range from 0% to 200% based on different performance outcomes. Weighted-average grant date fair value of RSU and PRSU awards assumed through acquisition is based on the fair value on the date assumed.

Payment of the underlying shares in connection with the vesting of RSU and PRSU awards generally triggers a tax obligation for the employee, which is required to be remitted to the relevant tax authorities. With respect to RSUs and PRSUs settled in shares, we have agreed to withhold shares of common stock otherwise issuable under the RSU and PRSU awards to cover certain of these tax obligations, with the net shares issued to the employee accounted for as outstanding common stock. We withheld 2,027,800, 1,900,710 and 2,511,512 shares of common stock to cover tax obligations associated with the payment of shares upon vesting of stock awards and remitted cash of $297 million, $243 million and $316 million to the appropriate tax authorities for the years ended December 31, 2023, 2022 and 2021, respectively.

Our ESPP allows eligible employees to contribute up to 15% of their eligible earnings toward the semi-annual purchase of our shares of common stock at a discounted price, subject to an annual maximum dollar amount. Employees can purchase stock at a 15% discount applied to the closing stock price on the first or last day of the six-month offering period, whichever price is lower. The number of shares issued under our ESPP was 1,771,475, 2,079,086 and 2,189,542 for the years ended December 31, 2023, 2022 and 2021, respectively. In June 2023, the stockholders of the Company approved an amendment to our ESPP plan, increasing the share reserve to 14,000,000. As of December 31, 2023, the number of securities remaining available for future sale and issuance under the ESPP was 13,291,951.

The objective for the investment portfolio of the Pension Plan is to achieve a long-term nominal rate of return, net of fees, that exceeds the Pension Plan's long-term expected rate of return on investments for funding purposes. To meet this objective, our investment strategy is governed by an asset allocation policy, whereby a targeted allocation percentage is assigned to each asset

class as follows: 48% to equities; 35% to fixed income investments; and 17% to real estate, infrastructure and private assets. Actual allocations are allowed to deviate from target allocation percentages within a range for each asset class as defined in the investment policy. The long-term expected rate of return on plan assets was 7% and 5% for the years ended December 31, 2023 and 2022, respectively, while the actual rate of return on plan assets was 11% and (14)% for the years ended December 31, 2023 and 2022, respectively. The long-term expected rate of return on investments for funding purposes is 7% for the year ended December 31, 2024.

The components of net benefit recognized for the Pension Plan were as follows:


	Year Ended December 31,
(in millions)	2023		2022

Interest on projected benefit obligations	$	86	$	65
Amortization of actuarial gain	(59)		—
Expected return on pension plan assets	(97)		(71)




Net pension benefit	$	(70)	$	(6)

Investments of the Pension Plan are measured at fair value on a recurring basis, which is determined using quoted market prices or estimated fair values. As of both December 31, 2023 and 2022, 17% of the investment portfolio was valued at quoted prices in active markets for identical assets, 79% was valued using quoted prices for similar assets in active or inactive markets, or other observable inputs, and 4% was valued using unobservable inputs that are supported by little or no market activity, the majority of which used the net asset value per share (or its equivalent) as a practical expedient to measure the fair value.

The fair values of our Pension Plan assets and certain other postretirement benefit plan assets in aggregate were $1.3 billion and $1.2 billion as of December 31, 2023 and 2022, respectively. Certain investments, as a practical expedient, are reported at estimated fair value, utilizing net asset values of $10 million as of December 31, 2023, which are part of our Plan assets. Our accumulated benefit obligations in aggregate were $1.6 billion as of both December 31, 2023 and 2022. As a result, the plans were underfunded by approximately $350 million and $342 million as of December 31, 2023 and 2022, respectively, and were recorded in Other long-term liabilities on our Consolidated Balance Sheets. In determining our pension obligation for the years ended December 31, 2023, and 2022, we used a weighted-average discount rate of 5% and 6%, respectively.

During the years ended December 31, 2023 and 2022, we made contributions of $32 million and $37 million, respectively, to the benefit plans. We expect to make contributions to the Plan of $52 million through the year ending December 31, 2024.

Future benefits expected to be paid are approximately $104 million for the 12-month period ending December 31, 2024, $215 million in total for both of the 12-month periods ending December 31, 2025 and 2026, $223 million in total for both of the 12-month periods ending December 31, 2027 and 2028, and $571 million in total thereafter.

We sponsor retirement savings plans for the majority of our employees under Section 401(k) of the Internal Revenue Code and similar plans. The plans allow employees to contribute a portion of their pre-tax and post-tax income in accordance with specified guidelines. The plans provide that we match a percentage of employee contributions up to certain limits. Employer matching contributions were $171 million, $175 million and $190 million for the years ended December 31, 2023, 2022 and 2021, respectively.