Civil operating income margin for fiscal year 2017 was 6.6%, compared to 7.0% in the prior year. On a non-GAAP basis, operating margin for the year was 10.8%, compared to 8.9% in the prior year. Operating margins were favorably impacted by stronger program performance.

Health

Health revenues for fiscal year 2017 of $1.80 billion increased $685 million, or 61.3%, compared to the prior year. The revenue growth was primarily attributable to the acquired IS&GS Business and growth in our federal health business, partially offset by lower volume in commercial health.

Health operating margin for fiscal year 2017 was 12.7%, compared to 9.8% in the prior year. On a non-GAAP basis, operating margin for the year was 14.9%, compared to 12.4% in the prior year. Operating margins were favorably impacted by higher margins on certain IS&GS contracts.

Cash Flow Summary

Net cash provided by operating activities for the quarter were $164 million compared to $121 million in the prior year quarter. The higher operating cash inflows were primarily due to the favorable timing of working capital changes, partially offset by higher integration and restructuring costs and cash paid for income taxes.

Net cash used in investing activities for the quarter were $38 million compared to $8 million in the prior year quarter. The increased cash outflows were primarily due to higher purchases of property, plant and equipment.

Net cash used in financing activities for the quarter were $65 million compared to $227 million in the prior year quarter. The decrease in financing cash outflows were primarily due to lower repayments of long-term debt of $160 million.

Net cash provided by operating activities for the fiscal year were $526 million compared to $449 million in the prior year. The higher operating cash inflows were primarily due to the favorable timing of working capital changes, partially offset by higher integration and restructuring costs, higher payments for interest and cash paid for income taxes.

Net cash used in investing activities for the fiscal year were $71 million compared to net cash provided by $26 million in the prior year. The higher cash flows used were primarily due to cash proceeds received from both the acquisition of the IS&GS Business and the divestiture of the heavy construction business in fiscal 2016 and higher purchases of property, plant and equipment.

Net cash used in financing activities for the fiscal year were $429 million compared to $751 million in in the prior year. The decrease in financing cash outflows were primarily due to a special cash dividend payment in the prior year and lower debt repayments partially offset by higher borrowings in the prior year and higher dividend payments.

As of December 29, 2017, the Company had $390 million in cash and cash equivalents and $3.1 billion in long-term debt.

Share Repurchase Authorization

On February 16, 2018, the Company's Board of Directors authorized a new share repurchase program of up to 20 million shares of the Company's outstanding common stock. The shares may be repurchased from time to time in one or more open market repurchases or privately negotiated transactions, including accelerated share repurchase transactions. The actual timing, number and value of shares repurchased under the program will depend on a number of factors, including the market price of the Company's common stock, general market and economic conditions, applicable legal requirements, compliance with the terms of the Company's outstanding indebtedness and other considerations. There is no assurance as to the number of shares that will be repurchased, and the repurchase program may be suspended or discontinued at any time at the Company's discretion. This share repurchase authorization replaces the previous share repurchase authorization announced in December 2013.

New Business Awards

Net bookings totaled $2.3 billion in the fourth quarter of fiscal year 2017 and $9.7 billion for fiscal year 2017, representing a book-to-bill ratio of 0.9 and 1.0 for the fourth quarter and fiscal year 2017, respectively.

Notable recent awards received include:

• United States Army: Leidos was awarded a competitive task order to provide mission support services to the U.S. Army's Communications-Electronics Research, Development and Engineering Center Prototyping Integration and Testing Division ("PI&TD"). The single-award task order has a one-year base period of performance, four one-year options, and a total contract value of approximately $230 million. Leidos' work will help PI&TD integrate C4ISR systems into military and aerospace equipment and weapons systems, as well as support evaluation exercises.

• NASA Johnson Space Center: Leidos was awarded a follow-on contract to provide sustained engineering and mission support under the Cargo Mission Contract 3 for the International Space Station ("ISS"). Under the contract, Leidos will apply multiple technology innovations to improve capabilities for cargo packing, as well as customer-focused enhancements that provide the ISS with cost-effective solutions in a dynamic and challenging environment. The single-award cost-plus fixed-fee contract has a two-year base period of performance, three option periods, and a maximum potential value of $159 million.

• Office of Naval Research: Leidos was awarded a cost-plus-fixed fee contract for the Sea Hunter II -Autonomous Continuous Trail Unmanned Vessel Hull Number 2. This contract contains options, which if exercised, would bring the contract value to approximately $44 million. Leidos will provide research, development, test and evaluation for the second vessel.

• U.S. Intelligence Community: The Company was awarded contracts valued at $600 million, if all options are exercised, by U.S. national security and intelligence clients. Though the specific nature of these contracts is classified, they all encompass mission-critical services that help to counter global threats and strengthen national security.

The Company's backlog at the end of fiscal year 2017 was $17.5 billion, of which $5.0 billion was funded.

Forward Guidance

The Company's outlook for fiscal year 2018 is as follows:

• Revenues of $10.25 billion to $10.65 billion;
• Adjusted EBITDA margins of 10.1% to 10.4%;
• Non-GAAP diluted earnings per share of $4.15 to $4.50; and
• Cash flows provided by operating activities at or above $675 million.

Non-GAAP diluted earnings per share excludes amortization of acquired intangible assets, asset impairment charges, restructuring expenses, acquisition and integration costs, amortization of equity method investments, gains and losses on sale of assets and businesses, promissory note impairment and adjustments to the income tax provision to reflect non-GAAP exclusions. See Leidos' non-GAAP financial measures and the related reconciliation included elsewhere in this release.

The Company does not provide a reconciliation of forward-looking adjusted EBITDA margins (non-GAAP) or non-GAAP diluted earnings per share to GAAP net income (loss), due to the inherent difficulty in forecasting and quantifying certain amounts that are necessary for such reconciliation. Because certain deductions for non-GAAP exclusions used to calculate projected net income (loss) may vary significantly based on actual events, the Company is not able to forecast on a GAAP basis with reasonable certainty all deductions needed in order to provide a GAAP calculation of projected net income (loss) at this time. The amounts of these deductions may be material and, therefore, could result in projected GAAP net income (loss) and diluted earnings per share being materially less than projected adjusted EBITDA margins (non-GAAP) and non-GAAP diluted earnings per share.

Tax Cuts and Jobs Act

In December 2017, the U.S. Government enacted the Tax Cuts and Jobs Act ("Tax Act"). The Company expects to be impacted by many of the Tax Act provisions, including most notably the reduction in the U.S. federal statutory tax rate from 35% to 21%. The lower rate applies to earnings starting in fiscal year 2018, however due to the Tax Act's 2017 enactment date, the Company recognized a one-time net benefit of $115 million to our fourth quarter GAAP net income. The majority of the benefit is due to the revaluation of net deferred tax liabilities at the lower rate which contributed $0.75 to GAAP diluted EPS in the quarter. The one-time Tax Act benefit is excluded from our non-GAAP net income and EPS results. Taking into account the Tax Act changes, we expect our normalized fiscal year 2018 GAAP effective tax rate to be approximately 23% to 24%.