Note 10 – Employee Compensation and Benefit Plans

T-Mobile maintains the 2013 Omnibus Incentive Plan, which authorized the issuance of up to 63 million shares of common stock. Under the incentive plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units, and performance awards to employees, consultants, advisors and non-employee directors. As of December 31, 2015, there were 29 million shares of common stock available for future grants under the incentive plan.

T-Mobile grants restricted stock units (“RSU”) to eligible employees and certain non-employee directors and performance stock units (“PSU”) to eligible key executives of the Company. RSUs entitle the grantee to receive shares of T-Mobile common stock at the end of a vesting period of generally up to 3 years. PSUs entitle the holder to receive shares of T-Mobile common stock at the end of a vesting period of generally up to 3 years if the performance goal is achieved. The number of shares ultimately received is dependent on T-Mobile's business performance against the specified performance goal. The Company also maintains an employee stock purchase plan (“ESPP”).

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



(in millions)	December 31, 2015		December 31, 2014		December 31, 2013
Stock-based compensation expense	$	201	$	196	$	100
Income tax benefit related to stock-based compensation	71		73		38
Realized excess tax benefit	79		34		—

Stock Awards

The following activity occurred under the RSU and PSU awards:



(in millions, except shares, per share and contractual life amounts)	Number of Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Nonvested, December 31, 2014	19,952,089		$	24.15	1.1	$	538
Granted	9,760,057		35.56
Vested	(11,956,345	)	25.28
Forfeited	(1,421,530	)	27.36
Nonvested, December 31, 2015	16,334,271		$	29.95	1.2	$	639

Vesting of the stock awards triggers a tax obligation for the employee, which is required to be remitted to the relevant tax authorities. The Company has agreed to withhold stock units from the employee to cover the tax obligation. The Company withheld 4,176,464 and 2,203,673 stock units to cover tax obligations associated with vesting of stock awards and remitted cash of $156 million and $73 million to the appropriate tax authorities for the years ended December 31, 2015 and 2014, respectively. The net shares issued to the employee are accounted for as outstanding common stock.

For the years ended December 31, 2014 and 2013, the weighted average fair value per stock award granted was $28.52 and $22.07, respectively. As of December 31, 2015, total unrecognized stock-based compensation expense related to non-vested stock awards, net of estimated forfeitures, was $327 million, before income taxes, which is expected to be recognized over a weighted-average period of 2.0 years. The total fair value of stock awards vested was $445 million, $209 million and $2 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Stock Options

Prior to the business combination, MetroPCS had established the MetroPCS Communications, Inc. 2010 Equity Incentive Compensation Plan, the Amended and Restated MetroPCS Communications, Inc. 2004 Equity Incentive Compensation Plan and the Second Amended and Restated 1995 Stock Option Plan (“Predecessor Plans”). Following stockholder approval of the Company’s 2013 Omnibus Incentive Plan, no new awards may be granted under the Predecessor Plans.

The following activity occurred under the Predecessor Plans:



	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)
Outstanding and Exercisable, December 31, 2014	4,348,912		$	24.96	3.7
Exercised	(2,381,650	)	19.91
Expired	(142,908	)	38.32
Outstanding and exercisable, December 31, 2015	1,824,354		$	30.50	2.7

Stock options exercised under the Predecessor Plans generated proceeds of approximately $47 million and $27 million for the years ended December 31, 2015 and 2014, respectively.

Employee Retirement Savings Plan

The Company sponsors a retirement savings plan for the majority of its employees under section 401(k) of the Internal Revenue Code and similar plans. The plans allow employees to contribute a portion of their pretax income in accordance with specified guidelines. The plans match a percentage of employee contributions up to certain limits. Employer matching contributions were $73 million, $66 million and $58 million for the years ended December 31, 2015, 2014 and 2013, respectively.

Employee Stock Purchase Plan

The Company’s ESPP allows eligible employees to contribute up to 15% of their eligible earnings toward the semi-annual purchase of the Company’s 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 the Company’s ESPP was 761,085 for the year ended December 31, 2015.

Legacy Long Term Incentive Plan

Prior to the business combination, the Company maintained a performance-based Long Term Incentive Plan (“LTIP”) which aligned to the Company's long-term business strategy. As of December 31, 2015, there were LTIP awards outstanding for the 2013 LTIP. No new awards are expected to be granted under the LTIP. Compensation expense reported within operating expenses related to the Company's LTIP was $27 million, $44 million and $63 million for the years ended December 31, 2015, 2014 and 2013, respectively. Payments of $57 million, $60 million and $61 million were made to participants related to T-Mobile’s LTIP during the years ended December 31, 2015, 2014 and 2013, respectively.