Employee Benefit Plans

9 Months Ended

Dec. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Employee Benefit Plans

Employee Benefit Plans

The Company provides defined benefit pension plans and defined contribution plans for the majority of its employees. The Company has tax-qualified defined benefit plans, a supplemental (nonqualified) defined benefit pension plan, a defined contribution plan and a supplemental (non-qualified) defined contribution plan. A qualified plan meets the requirements of certain sections of the Internal Revenue Code and, generally, contributions to qualified plans are tax deductible. A qualified plan typically provides benefits to a broad group of employees and may not discriminate in favor of highly compensated employees in coverage, benefits or contributions. In addition, the Company provides medical and life insurance benefits to certain retirees and their eligible dependents through its postretirement plans.

In connection with the Distribution, the Company transferred its obligation for pension benefits and other postretirement benefit ("PRB") plans for all current and former employees of Sporting Group to Vista Outdoor. The transfer of this obligation reduced the Company's pension liabilities by $223,790, pension assets by $163,034 and accumulated other comprehensive loss for pension benefits by $97,764. The transfer of this obligation also reduced the Company's PRB liabilities by $1,963 and accumulated other comprehensive gain for PRB benefits by $1,727.

Defined Benefit Plans

The Company's noncontributory defined benefit pension plans include the following legacy Alliant Techsystems, Inc. plans: "Alliant Techsystems, Inc. Pension and Retirement Plan" and "Thiokol Propulsion Pension Plan" (the “ATK Plans”). The Company acquired the following two pension plans applicable to legacy Orbital employees in connection with the Merger: "Fairchild Bargained Plan" and "Fairchild Space and Defense Plan" (the “Orbital Plans” and together with the ATK Plans, the “Plans”). The Orbital Plans were merged into the Alliant Techsystems, Inc. Pension and Retirement Plan on December 31, 2015 and the combined plan's name was changed to the Orbital ATK, Inc. Pension and Retirement Plan.

The Company is required to reflect the funded status of the pension and PRB plans on the consolidated balance sheet. The funded status of the Plans is measured as the difference between the plan assets at fair value and the projected benefit obligation. The Company has recognized the aggregate of all underfunded plans within the accrued pension liability and postretirement and postemployment benefits liabilities. The Company has recognized the aggregate of all overfunded plans within other noncurrent assets. The portion of the amount by which the actuarial present value of benefits included in the projected benefit obligation exceeds the fair value of plan assets, payable in the next 12 months, is reflected in other accrued liabilities.

Previously unrecognized differences between actual amounts and estimates based on actuarial assumptions are included in accumulated other comprehensive loss in the consolidated balance sheet and the difference between actual amounts and estimates based on actuarial assumptions has been recognized in other comprehensive income in the period in which they occur.

The Company's measurement date for remeasuring its plan assets and benefit obligations is December 31.

Pension Plans.    The ATK Plans are qualified noncontributory defined benefit pension plans that cover substantially all legacy ATK employees hired prior to January 1, 2007. Eligible legacy ATK non-union employees hired on or after January 1, 2007 and certain union employees are not covered by a defined benefit plan but substantially all do receive an employer contribution through a defined contribution plan, discussed below. Effective with certain collective bargaining agreements on April 1, 2016, additional union pension benefits were frozen and the new cash balance formula applicable to pay and service was implemented. As a result of this plan amendments the projected benefit obligation was reduced by $2,295 . The ATK Plan is a cash balance formula that provides each affected employee with pay credits based on the sum of that employee's age plus years of pension service at December 31 of each calendar year, plus 4% annual interest credits. Prior to July 1, 2013 (January 1, 2014 and April 1, 2016 for certain union groups), the ATK Plans provided either pension benefits based on employee annual pay levels and years of credited service or stated amounts for each year of credited service. The Company funds the ATK Plans in accordance with federal requirements calculated using appropriate actuarial methods. Depending on the plan they are covered by, employees generally vest after three or five years. The Orbital Plans are frozen and no benefits are being accrued by employees. These plans currently are overfunded.

The Company also sponsors a nonqualified supplemental executive retirement plan which provides certain executives and highly compensated employees the opportunity to receive pension benefits in excess of those payable through tax-qualified pension plans. The benefit obligation of these plans is included in the pension information below.

Other Postretirement Benefit Plans.    Generally, employees who terminated employment from the Company on or before January 1, 2004 and were at least age 50 or 55 with at least five or ten years of service, depending on the provisions of the pension plan they are eligible for, are entitled to a pre- and/or post-65 health care company subsidy and retiree life insurance coverage. Employees who terminated employment after January 1, 2004, but before January 1, 2006, are eligible only for a pre-65 company subsidy. The portion of the health care premium cost borne by the Company for such benefits is based on the pension plan the employees are eligible for, years of service and age at termination.

The following table shows changes in the benefit obligation, plan assets and funded status of the Company's qualified and non-qualified pension plans and other PRB plans, including Orbital Plans. Benefit obligation balances presented below reflect the projected benefit obligation ("PBO") for pension plans and accumulated PRB obligations ("APBO") or other PRB plans.

	Pension Benefits						Other Postretirement Benefits
	Nine Months Ended December 31, 2015			Year Ended March 31, 2015			Nine Months Ended December 31, 2015			Year Ended March 31, 2015
Change in benefit obligation:
Benefit obligation at beginning of period	$	3,199,221		$	2,988,288		$	131,620		$	128,065
Service cost	14,445			23,182			1			3
Interest cost	91,044			129,236			3,378			4,803
Plan Amendments	(2,295		)	—			—			—
Actuarial loss (gain) (1)	(211,581		)	465,524			(13,106		)	12,255
Retiree contributions	—			—			3,302			4,729
Benefits paid	(138,166		)	(192,756		)	(10,858		)	(16,272		)
Impact of Distribution	—			(223,790		)	—			(1,963		)
Merger with Orbital Sciences	—			9,537			—			—
Benefit obligation at end of period	2,952,668			3,199,221			114,337			131,620
Change in plan assets:
Fair value of plan assets at beginning of period	2,348,795			2,426,013			63,678			61,055
Actual return on plan assets	(94,573		)	177,776			(1,716		)	4,397
Retiree contributions	—			—			3,302			4,729
Employer contributions	73,844			87,150			5,644			9,769
Benefits paid	(138,166		)	(192,756		)	(10,858		)	(16,272		)
Fair value of assets at February 9, 2015, transferred to Vista Outdoor (2)	—			(163,034		)	—			—
Merger with Orbital Sciences	—			13,646			—			—
Fair value of plan assets at end of period	2,189,900			2,348,795			60,050			63,678
Funded status	$	(762,768	)	$	(850,426	)	$	(54,287	)	$	(67,942	)

_________________________________________

(1) The mortality projection scale was updated from MP-2014 to MP-2015 at December 31, 2015. This change resulted in an actuarial gain of $50,000 and $4,000 for the Pension Benefits and Other Postretirement Benefits, respectively. The mortality table assumption was changed to the RP-2014 Aggregate table (employee and annuitant) with generational projection using Scale MP-2014 at March 31, 2015 resulting in actuarial losses of $189,000 and $13,000 for the Pension Benefits and Other Postretirement Benefits, respectively.

(2) The actual amount transferred to Vista Outdoor on February 9, 2015 was determined to be $158,514. The difference between this amount and the fair value of these assets at the time of transfer of $163,034 was treated as gain/loss on plan assets.

	Pension Benefits						Other Postretirement Benefits
	December 31, 2015			March 31, 2015			December 31, 2015			March 31, 2015
Noncurrent assets	$	4,264		$	4,318		$	—		$	—
Other current liabilities	(5,400		)	(3,743		)	(3,381		)	(3,436		)
Postretirement and postemployment benefit liabilities	—			—			(50,906		)	(64,506		)
Pension liabilities	(761,632		)	(851,001		)	—			—
Net amount recognized	$	(762,768	)	$	(850,426	)	$	(54,287	)	$	(67,942	)
Accumulated other comprehensive loss (income) related to:
Unrecognized net actuarial losses	$	1,407,947		$	1,520,459		$	15,795		$	25,906
Unrecognized prior service benefits	(131,068		)	(144,410		)	(9,724		)	(15,163		)
Accumulated other comprehensive loss (income)	$	1,276,879		$	1,376,049		$	6,071		$	10,743

The estimated amount that will be amortized from AOCI into net periodic benefit cost in 2016 is as follows:

	Pension			Other Postretirement Benefits
Recognized net actuarial losses	$	123,195		$	1,589
Amortization of prior service benefits	(20,605		)	(5,162		)
Total	$	102,590		$	(3,573	)

The accumulated benefit obligation for all defined benefit pension plans was $2,952,599 at December 31, 2015 and $3,197,143 at March 31, 2015.

	December 31, 2015		March 31, 2015
Information for pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	$	2,952,668	$	3,189,805
Accumulated benefit obligation	$	2,952,599	$	3,187,727
Fair value of plan assets	$	2,189,900	$	2,335,060

Components of net periodic benefit cost were as follows:

	Pension Benefits									Other Postretirement Benefits
	Nine Months Ended December 31,  2015			Years Ended						Nine Months Ended December 31, 2015			Years Ended
				March 31, 2015			March 31, 2014						March 31, 2015			March 31, 2014
Components of net periodic benefit cost:
Service cost	$	14,445		$	23,182		$	34,763		$	1		$	3		$	9
Interest cost	91,044			129,236			130,253			3,378			4,803			5,207
Expected return on plan assets	(120,352		)	(165,780		)	(161,111		)	(2,767		)	(3,553		)	(3,419		)
Amortization of unrecognized net loss	112,949			118,163			145,891			1,488			1,629			2,288
Amortization of unrecognized prior service cost	(15,638		)	(22,284		)	(20,984		)	(5,439		)	(8,362		)	(8,381		)
Net periodic benefit cost before special termination benefits cost / curtailment	82,448			82,517			128,812			(3,339		)	(5,480		)	(4,296		)
Special termination benefits cost / curtailment	—			2,469			—			—			—			—
Net periodic benefit cost	$	82,448		$	84,986		$	128,812		$	(3,339	)	$	(5,480	)	$	(4,296	)
Amounts reported in:
Continuing operations	$	82,448		$	81,038		$	120,812		$	(3,339	)	$	(5,496	)	$	(4,340	)
Discontinued operations	—			3,948			8,000			—			16			44
Net periodic benefit cost	$	82,448		$	84,986		$	128,812		$	(3,339	)	$	(5,480	)	$	(4,296	)

During fiscal 2015, the Company recorded a settlement expense of $2,469 to recognize the impact of lump sum benefit payments made in the non-qualified supplemental executive retirement plan.

The Medicare Prescription Drug, Improvement and Modernization Act of 2003 (the "Act") reduced the Company's APBO measured at December 31, 2005. One of the Company's other PRB plans is actuarially equivalent to Medicare, but the Company does not believe that the subsidies it will receive under the Act will be significant. Because the Company believes that participation levels in its other PRB plans will decline, the impact to the Company's results of operations in any period has not been and is not expected to be significant.

At the end of the 2015 transition period, the Company changed the approach used to measure service and interest costs for pension and other postretirement benefits. For the 2015 transition period, the Company measured service and interest costs utilizing a single weighted-average discount rate derived from the yield curve used to measure the plan obligations. For 2016, the Company elected to measure service and interest costs by applying the specific spot rates along that yield curve to the plans’ liability cash flows. The Company believes the new approach provides a more precise measurement of service and interest costs by aligning the timing of the plans’ liability cash flows to the corresponding spot rates on the yield curve. This change does not affect the measurement of our plan obligations. The Company has accounted for this change as a change in accounting estimate and, accordingly, has accounted for it on a prospective basis.

Assumptions

	Pension Benefits						Other Postretirement Benefits
	Nine Months Ended December 31,  2015		Years Ended				Nine Months Ended December 31,  2015		Years Ended
			March 31, 2015		March 31, 2014				March 31, 2015		March 31, 2014
Weighted-average assumptions used to determine benefit obligations at the end of each period
Discount rate	4.40	%	3.90	%	4.50	%	3.98	%	3.55	%	3.95	%
Rate of compensation increase:
Union	3.13	%	3.66	%	3.22	%
Salaried	3.62		3.14		3.47

	Pension Benefits						Other Postretirement Benefits
	Nine Months Ended December 31, 2015		Years Ended				Nine Months Ended December 31, 2015		Years Ended
			March 31, 2015		March 31, 2014				March 31, 2015		March 31, 2014
Weighted-average assumptions used to determine net periodic benefit cost for each period
Discount rate	3.90	%	4.50	%	4.35	%	3.55	%	3.95	%	3.80	%
Expected long-term rate of return on plan assets	7.25		7.25		7.25		5.00% / 6.25%		5.00% / 6.25%		5.00% / 6.25%
Rate of compensation increase:
Union	3.66	%	3.22	%	3.23	%
Salaried	3.14		3.47		3.49

In developing the expected long-term rate of return assumption, the Company considers input from its actuaries and other advisors, annualized returns of various major indices over a long-term time horizon and the Company's own historical 5-year and 10-year compounded investment returns. The expected long-term rate of return of 7.25% used in the 2015 transition period for the Plans was based on an asset allocation range of 20 - 45% in equity investments, 35 - 50% in fixed income investments, 0 - 10% in real estate/real asset investments, 15 - 30% collectively in hedge fund and private equity investments and 0 - 6% in cash investments. The actual return in any fiscal year will likely differ from the Company's assumption, but the Company estimates its return based on long-term projections and historical results. Therefore, any variance in a given year does not necessarily indicate that the assumption should be changed.

In developing the expected long-term rate of return assumption for other PRB plans, the Company considers input from actuaries, historical returns and annualized returns of various major indices over long periods. The expected long-term rates of returns are based on the weighted average asset allocation between the assets held within the 401(h) and those held in fixed income investments.

Assumed Health Care Cost Trend Rates Used to Measure Expected Cost of Benefits

	December 31, 2016		December 31, 2015
Weighted average health care cost trend rate	6.10	%	6.10	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50	%	4.50	%
Fiscal year that the rate reaches the ultimate trend rate	2027		2027

Since fiscal 2006, health care cost trend rates have been set specifically for each benefit plan and design. Assumed health care cost trend rates have a significant effect on the amounts reported for health care plans. A one percentage point increase or decrease in the assumed health care cost trend rates would have the following effects:

	One Percentage Point Increase		One Percentage Point Decrease
Effect on total of service and interest cost	$	286	$	(253	)
Effect on postretirement benefit obligation	$	6,888	$	(6,118	)

Plan Assets

Pension.    Pension plan weighted-average asset allocations:

	Anticipated 2016				Actual
	Low		High		December 31, 2015		March 31, 2015
Asset Category:
Domestic equity	10.0	%	25.0	%	19.9	%	20.7	%
International equity	10.0	%	20.0	%	13.1	%	13.7	%
Fixed income	35.0	%	50.0	%	40.5	%	42.5	%
Real estate	—	%	10.0	%	5.0	%	4.8	%
Hedge funds/private equity	15.0	%	30.0	%	16.8	%	14.8	%
Other investments/cash	—	%	6.0	%	4.7	%	3.5	%

The Company has a committee which, assisted by outside consultants, evaluates the objectives and investment policies concerning its long-term investment goals and asset allocation strategies. Plan assets are invested in various asset classes that are expected to produce a sufficient level of diversification and investment return over the long term. The investment goals are (1) to meet or exceed the assumed actuarial rate of return over the long term within reasonable and prudent levels of risk, and (2) to preserve the real purchasing power of assets to meet future obligations. The nature and duration of benefit obligations, along with assumptions concerning asset class returns and return correlations, are considered when determining an appropriate asset allocation to achieve the investment objectives. Pension plan assets for the Company's qualified pension plans are held in a trust for the benefit of the plan participants and are invested in a diversified portfolio of equity investments, fixed income investments, real asset investments, hedge funds, private equity and cash. Risk targets are established and monitored against acceptable ranges. All investment policies and procedures are designed to ensure that the plans' investments are in compliance with the Employee Retirement Income Security Act. Guidelines are established defining permitted investments within each asset class.

During the 2015 transition period, the Company implemented an investment strategy derived from the asset-liability study conducted during fiscal 2013. The results of the asset-liability study reinforced the emphasis on managing the volatility of pension assets relative to pension liabilities while still achieving a competitive investment return, achieving diversification between and within various asset classes and managing other risks. In order to manage the volatility between the value of pension assets and liabilities, the Company has maintained an allocation to long-duration fixed income investments. The Company regularly reviews its actual asset allocation and periodically rebalances its investments to the targeted allocation when considered appropriate. Target allocation ranges are guidelines, not limitations, and occasionally due to market conditions and other factors actual asset allocation may vary above or below a target.

The implementation of the investment strategy discussed above is executed through a variety of investment structures such as: direct share or bond ownership, common/collective trusts, or registered investment companies. Valuation methodologies differ for each of these structures. The valuation methodologies used for these investments structures are as follows:

U.S. Government Securities, Corporate Debt, Common and Preferred Stock, Other Investments and Registered Investment Companies:    Investments are valued at the closing price reported on the active market on which the individual securities are traded.

Common/Collective Trusts:    Investments in a collective investment vehicle are valued by multiplying the investee company's net asset value per share with the number of units or shares owned at the valuation date as determined by the investee company. Net asset value per share is determined by the investee company's custodian or fund administrator by deducting from the value of the assets of the investee company all of its liabilities and the resulting number is divided by the outstanding number of shares or units. Investments held by the CCT, including collateral invested for securities on loan, are valued on the basis of valuations furnished by a pricing service approved by the CCT's investment manager, which determines valuations using methods based on market transactions for comparable securities and various relationships between securities which are generally recognized by institutional traders, or at fair value as determined in good faith by the CCT's investment manager.

Partnership/Joint Venture Interests:    Given the inherent illiquidity of many partnership/joint venture investments, these investments are generally valued based on unobservable inputs that reflect the reporting entity's own assumptions about the assumptions that market participants would use pricing the asset. While the valuation methodologies may differ among each entity, the method for valuing these assets is primarily net asset values; other methods may include, but are not limited to, discounted cash flow analysis and comparable trading data for similar investments.

Funds in Insurance Company Accounts:    These investments are valued at fair value by discounting the related cash flows based on current yields of similar instruments with comparable durations considering the credit-worthiness of the issuer.

The methods described above may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

Fair Value: Pension plan investments using the fair value hierarchy discussed in Note 3 at December 31, 2015 consisted of the following:

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Interest-bearing cash	$	—	$	33,271	$	—	$	33,271
U.S. Government securities	62,428		5,939		—		68,367
Corporate debt	—		405,898		95		405,993
Common stock	88,928		6,842		—		95,770
Partnership/joint venture interest	—		—		709,251		709,251
Other investments	156		1,940		—		2,096
Common/collective trusts	—		609,852		—		609,852
Registered investment companies	59,366		164,696		—		224,062
Value of funds in insurance company accounts	—		40,195		1,043		41,238
Total	$	210,878	$	1,268,633	$	710,389	$	2,189,900

Pension plan investments using the fair value hierarchy discussed in Note 3 at March 31, 2015 consisted of the following:

	Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)			Total
Interest-bearing cash	$	—		$	3,279		$	—		$	3,279
U.S. Government securities	158,938			11,546			—			170,484
Corporate debt	—			410,035			187			410,222
Common stock	110,932			5,289			—			116,221
Partnership/joint venture interest	—			—			746,305			746,305
Other investments	5			3,121			—			3,126
Common/collective trusts	—			743,960			—			743,960
Registered investment companies	131,251			145,649			—			276,900
Value of funds in insurance company accounts	—			42,190			1,076			43,266
Total	401,126			1,365,069			747,568			2,513,763
Fair value of assets at March 31, 2015 transferred to Vista Outdoor	(26,324		)	(89,584		)	(49,060		)	(164,968		)
Fair Value of plan assets at end of year	$	374,802		$	1,275,485		$	698,508		$	2,348,795

Changes in Level 3 assets consisted of the following:

	Corporate Debt			Insurance Contracts			Partnerships/ Joint Ventures
Balance, March 31, 2014	$	199		$	1,131		$	689,073
Realized (losses) gains	—			6			38,614
Net unrealized (losses) gains	1			(2		)	(5,558		)
Net purchases, issuances, and settlements	(13		)	(59		)	24,176
Net transfers into (out of) Level 3	—			—			—
Balance, March 31, 2015	187			1,076			746,305
Realized (losses) gains	1			16			24,088
Net unrealized (losses) gains	1			(7		)	(37,868		)
Net purchases, issuances and settlements	(94		)	(42		)	(23,274		)
Net transfers into (out of) Level 3	—			—			—
Balance, December 31, 2015	$	95		$	1,043		$	709,251

There was no direct ownership of the Company common stock included in plan assets at any of the periods presented.

Other Postretirement Benefits.    The Company's other PRB obligations were 52.5% and 48.4% pre-funded at December 31, 2015 and March 31, 2015, respectively.

Portions of the assets are held in a 401(h) account held within the pension master trust and are invested in the same manner as the pension assets. Approximately 44% and 44% of the assets were held in the 401(h) account at December 31, 2015 and March 31, 2015, respectively. The remaining assets are in fixed income investments. The Company's investment objective for the other PRB plan assets is the preservation and safety of capital.

Contributions

During the 2015 transition period, the Company contributed $72,000 directly to the ATK Plans' pension trust and $1,845 directly to retirees under its supplemental (nonqualified) executive retirement plan. The Company also contributed $5,644 to its other PRB plans. The Company is required to make contributions of $37,000 to meet its legally required minimum contributions for 2016. The Company also expects to distribute approximately $5,400 directly to retirees under its supplemental executive retirement plans and to contribute approximately $7,552 to its other postretirement benefit plans in 2016.

Expected Future Benefit Payments

The following benefit payments, which reflect expected future service, are expected to be paid in the years ending December 31. The pension benefits will be paid primarily out of the pension trust. The postretirement benefit payments are shown net of the expected subsidy for the Medicare prescription drug benefit under the Medicare Prescription Drug, Improvement and Modernization Act of 2003 which are not material to be presented separately.

	Pension Benefits		Other Postretirement Benefits
2016	$	189,200	$	10,547
2017	191,900		10,359
2018	195,800		10,106
2019	200,800		9,801
2020	204,400		9,482
2021 through 2025	1,043,300		41,164

Termination

In the event the Company terminates any of the plans under conditions in which the plan's assets exceed that plan's obligations, U.S. Government regulations require that a fair allocation of any of the plan's assets based on plan contributions that were reimbursed under U.S. Government contracts will be returned to the U.S. Government.

Defined Contribution Plan

Through December 31, 2015, the Company also sponsored two defined contribution plans - the Alliant Techsystems Inc. 401(k) Plan and the Deferred Salary and Profit Sharing Plan for Employees of Orbital Sciences Corporation (the "Orbital Sciences 401(k) Plan"). Participation in these plans was available to substantially all U.S. employees. Effective January 1, 2016, the Orbital Sciences 401(k) Plan merged into the Alliant Techsystems Inc. 401(k) Plan, and the Alliant Techsystems Inc. 401(k) Plan was renamed the Orbital ATK, Inc. 401(k) Plan.

The Orbital ATK, Inc. 401(k) Plan (formerly named the Alliant Techsystems Inc. 401(k) Plan) is a 401(k) plan, with an employee stock ownership ("ESOP") feature, to which employees may contribute up to 50% of their pay (highly compensated employees are subject to limitations). Employee contributions are invested, at the employees' direction, among a variety of investment alternatives including a Company common stock fund. Participants may transfer amounts into and out of the investment alternatives at any time, except for the Company common stock fund. Any dividends declared on the Company common stock can be either reinvested within the Company common stock fund or provided as a cash payment. Effective January 1, 2013 employees no longer had the option to invest in the Company common stock fund, other than for the reinvestment of dividends paid on the Company common stock in participants' accounts. Balances in the fund prior to January 1, 2013 remain in the fund unless distributed or transferred. Effective January 1, 2004, the Company matching contribution and non-elective contribution to this plan depends on a participant's years of service, pension plan participation and certain other factors. Participants may receive:

• a matching contribution of 100% of the first 3% of the participant's contributed pay plus 50% of the next 2% of the participant's contributed pay, or

• a matching contribution of 50% of the first 6% of the participant's contributed pay, or

• a matching contribution of 100% of the first 3% of the participant's contributed pay plus 50% of the next 3% of the participant's contributed pay (subject to one-year vesting) and a non-elective contribution based on recognized compensation, age and service (subject to three-year vesting), or

• an automatic enrollment of a 6% pre-tax contribution rate (of which the participant can either change or opt out) along with a matching contribution of 100% of the first 3% of the participant's contributed pay plus 50% of the next 3% of the participant's contributed pay (subject to one-year vesting) and a non-elective contribution based on recognized compensation, age and service (subject to three-year vesting), or

• a non-elective contribution based on the recognized compensation, age and service (subject to three-year vesting), or

• no matching contribution

The Company's contributions to the plan were $41,028 in the 2015 transition period, $51,205 in fiscal 2015 and $48,379 in fiscal 2014.

At December 31, 2015, the Company had approximately nine thousand U.S. employees eligible under the plan. The Company has union-represented employees at five locations, comprising less than 20% of its total workforce. One location has two separate bargaining units, each with its own collective bargaining agreement (“CBA”). One location is currently negotiating its initial CBA with the Company.  The Company’s current CBAs expire in 2016 and 2017.

The Deferred Salary and Profit Sharing Plan for Employees of Orbital Sciences Corporation, which merged with the Orbital ATK, Inc. 401(k) Plan effective January 1, 2016, was a 401(k) plan to which legacy Orbital employees could contribute up to 30% of their pay (highly compensated employees were subject to limitations). Employee contributions were invested, at the employees' direction, among a variety of investment alternatives including the Company common stock fund. Participants could transfer amounts into and out of the investment alternatives at any time, except for the Company common stock fund. Any dividends declared on the Company common stock could be reinvested within the Company common stock fund. Effective February 9, 2015, employees no longer had the option to invest in the Company common stock fund, other than for the reinvestment of dividends paid on the Company common stock in participants' accounts. Balances in the fund prior to February 9, 2015 remained in the fund unless distributed or transferred. Participants received a matching contribution of 100% of the first 5% of the participant's contributed pay. The Company could also make an annual discretionary profit sharing contribution based on the participant’s compensation. The Company's contributions to the plan were $2,778 in fiscal 2015.