STOCK OWNERSHIP AND COMPENSATION PLANS

Employee and Non-employee Directors Stock Ownership Programs

In 2005, the Company established the ELTIP to replace the Company's prior plan. The ELTIP provides for three types of awards: (a) stock options, (b) stock appreciation rights and (c) stock awards. The ELTIP provides for the grant to eligible employees of either non-qualified or incentive stock options, or both, to purchase shares of Company common stock at an exercise price no less than the fair market value of the Company's common stock on the date of grant. Grants of stock appreciation rights allow eligible employees to receive a payment based on the appreciation of Company common stock in cash, shares of Company common stock or a combination thereof. The stock appreciation rights are granted at an exercise price no less than the fair market value of the Company's common stock on the date of grant. Stock options and stock appreciation rights granted under the ELTIP expire on the date designated by the Board of Directors but in no event more than ten years from date of grant. No stock appreciation rights have been granted under the ELTIP. The stock options and shares are subject to forfeiture if employment terminates prior to the end of the vesting period prescribed by the Board of Directors. For all award types, the vesting period is generally over three years from the date of grant. For performance share unit awards, the actual amount of shares earned is based on the achievement of the performance goals specified in the awards. The maximum number of shares of Company common stock that may be optioned or granted under the ELTIP is approximately 71 million shares.

In 2005, the Company established the DLTIP to replace the Company's prior plan. The DLTIP provides for the grant to non-employee directors of non-qualified stock options to purchase shares of Company common stock at an exercise price no less than the fair market value of the Company's common stock on the date of grant. The DLTIP also permits awards of restricted stock and restricted stock units to non-employee directors. Stock options granted under the DLTIP expire on the date designated by the Board of Directors but in no event more than ten years from date of grant, and generally become exercisable in three equal annual installments beginning on the first anniversary date of the grant of the option regardless of whether the optionee remains a director of the Company. The maximum number of shares that may be issued under the DLTIP is 2.4 million shares. For the years ended December 31, 2017, 2016 and 2015, grants under the DLTIP totaled 13 thousand shares, 21 thousand shares and 31 thousand shares, respectively.

The Company's practice has been to issue shares related to its stock-based compensation program from shares of its common stock held in treasury or by issuing new shares of its common stock. See Note 15 for further information regarding the Company's share repurchase program.

The fair value of each stock option award granted was estimated on the date of grant using a Black-Scholes option-valuation model. The expected volatility under the Black-Scholes option-valuation model was based on historical volatilities of the Company's common stock. The dividend yield was based on the approved annual dividend rate in effect and current market price of the underlying common stock at the time of grant. The risk-free interest rate was based on the U.S. Treasury yield curve in effect at the time of grant for bonds with maturities consistent with the expected holding period of the related award. The expected holding period was estimated using the historical exercise behavior of employees.

The weighted average assumptions used in valuing stock options granted in the periods presented were:



	2017	2016	2015

Fair value at grant date	$15.98	$10.35	$11.57
Expected volatility	19.8%	21.6%	21%
Dividend yield	1.9%	2.4%	2.1%
Risk-free interest rate	2.1%	1.4%	1.7%
Expected holding period, in years	5.2	5.3	5.3

The fair value of restricted stock awards, restricted stock units and performance share units is the average market price of the Company's common stock at the date of grant.

The following summarizes the activity relative to stock option awards for 2017:



	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value

Options outstanding, beginning of year	9.1		$	62.27
Options granted	1.8		96.02
Options exercised	(2.2	)	58.91
Options forfeited and canceled	(0.2	)	79.74
Options outstanding, end of year	8.5		$	70.11	7.1	$	243

Exercisable, end of year	4.4		$	60.81	5.9	$	166
Vested and expected to vest, end of year	8.3		$	69.73	7.1	$	240

The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the Company's closing common stock price on the last trading day of 2017 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2017. This amount changes based on the fair market value of the Company's common stock. Total intrinsic value of options exercised in 2017, 2016 and 2015 was $94 million, $30 million and $21 million, respectively.

As of December 31, 2017, there was $16 million of unrecognized stock-based compensation cost related to nonvested stock options which is expected to be recognized over a weighted average period of 1.9 years.

The following summarizes the activity relative to stock awards, including restricted stock awards, restricted stock units and performance share units, for 2017, 2016 and 2015:



	2017				2016				2015
	Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value

Shares outstanding, beginning of year	1.5		$	63.88	1.7		$	59.92	1.9		$	55.50
Shares granted	0.4		96.27		0.6		67.26		0.6		71.17
Shares vested	(0.6	)	57.59		(0.4	)	58.98		(0.3	)	55.74
Shares forfeited and canceled	—		—		(0.4	)	57.31		(0.5	)	58.18
Shares outstanding, end of year	1.3		$	77.90	1.5		$	63.88	1.7		$	59.92

As of December 31, 2017, there was $39 million of unrecognized stock-based compensation cost related to nonvested stock awards, which is expected to be recognized over a weighted average period of 1.8 years. Total fair value of shares vested was $58 million, $28 million and $20 million for the years ended December 31, 2017, 2016 and 2015, respectively. The amount of unrecognized stock-based compensation cost is subject to change based on changes, if any, to management's best estimates of the achievement of the performance goals specified in such awards and the resulting number of shares that will be earned at the end of the performance periods.

For the years ended December 31, 2017, 2016 and 2015, stock-based compensation expense totaled $79 million, $69 million and $52 million, respectively. Income tax benefits recognized in the consolidated statements of operations related to stock-based compensation expense totaled $67 million, $32 million and $20 million for the years ended December 31, 2017, 2016 and 2015, respectively, which includes excess tax benefits associated with stock-based compensation arrangements of $37 million and $9 million for the years ended December 31, 2017 and 2016, respectively.

Employee Stock Purchase Plan

Under the Company's ESPP, substantially all employees can elect to have up to 10% of their annual wages withheld to purchase Quest Diagnostics common stock. The purchase price of the stock is 85% of the market price of the Company's common stock on the last business day of each calendar month. Under the ESPP, the maximum number of shares of Quest Diagnostics common stock which may be purchased by eligible employees is 9 million. Approximately 278 thousand, 332 thousand and 349 thousand shares of common stock were purchased by eligible employees in 2017, 2016 and 2015, respectively.

Defined Contribution Plans

The Company maintains qualified defined contribution plans covering substantially all of its employees. The maximum Company matching contribution is 5% of eligible employee compensation. The Company's expense for contributions to its defined contribution plans aggregated $76 million, $76 million and $77 million for 2017, 2016 and 2015, respectively.

Supplemental Deferred Compensation Plans

The Company has a supplemental deferred compensation plan that is an unfunded, non-qualified plan that provides for certain management and highly compensated employees to defer up to 50% of their salary in excess of their defined contribution plan limits and for certain eligible employees, up to 95% of their variable incentive compensation. The maximum Company matching contribution is 5% of eligible employee compensation. The compensation deferred under this plan, together with Company matching amounts, are credited with earnings or losses measured by the mirrored rate of return on investments elected by plan participants. Each plan participant is fully vested in all deferred compensation, Company match and earnings credited to their account. The amounts accrued under the Company's deferred compensation plans were $58 million and $51 million as of December 31, 2017 and 2016, respectively. Although the Company is currently contributing all participant deferrals and matching amounts to trusts, the funds in these trusts, totaling $58 million and $51 million as of December 31, 2017 and 2016, respectively, are general assets of the Company and are subject to any claims of the Company's creditors.

The Company also offers certain employees the opportunity to participate in a non-qualified deferred compensation program. Eligible participants are allowed to defer up to $20 thousand of eligible compensation per year. The Company matches employee contributions equal to 25%, up to a maximum of $5 thousand per plan year. A participant's deferrals, together with Company matching credits, are “invested” at the direction of the employee in a hypothetical portfolio of investments which are tracked by an administrator. Each participant is fully vested in their deferred compensation and vests in Company matching contributions over a four-year period at 25% per year. This plan was amended effective January 1, 2018 so that future deferrals under the plan may only be made by participants who made deferrals under the plan in 2017. The amounts accrued under this plan were $45 million and $39 million as of December 31, 2017 and 2016, respectively. The Company purchases life insurance policies, with the Company named as beneficiary of the policies, for the purpose of funding the program's liability. The cash surrender value of such life insurance policies was $37 million and $32 million as of December 31, 2017 and 2016, respectively.

For the years ended December 31, 2017, 2016 and 2015, the Company's expense for matching contributions to these plans were not material.