Background

In accordance with 10 U.S.C. §115(a), Congress sets the maximum size of the active component of the Armed Forces annually, typically in a National Defense Authorization Act (NDAA). The active component comprises the full-time personnel of the Army, Navy, Marine Corps, Air Force, Coast Guard, and Space Force. Congress also appropriates funds for the pay and benefits of these personnel.

End-strength specifically refers to the actual number of personnel in a branch on the last day of the fiscal year (i.e., September 30). While Congress authorizes minimum and maximum end-strengths, each military service manages its force through recruiting and retention efforts to achieve an actual end-strength.

Typically, actual end-strength falls within the congressionally authorized minimum and maximum end-strengths. However, there are circumstances in which the actual end-strength may fall outside the authorized range. For example, in accordance with 10 U.S.C. §115(f), the Secretary of Defense (who is using "Secretary of War" as a "secondary title" under Executive Order 14347 dated September 5, 2025) may—after determining "such action is in the national interest"—vary the end-strength of any of the services by no more than 3%. Recruiting and retention shortfalls may leave one or more of the services with end-strength levels below their minimum authorized strength.

In accordance with 10 U.S.C. §113a(b)(2), the Secretary of Defense is required to submit end-strength requests for all branches of the active component in an annual request to Congress. Congress is not bound by these requests but considers them while deliberating end-strength levels.

End-Strength Trends, FY2001-FY2027

Congress has varied the Armed Forces' authorized end-strengths over time in response to factors such as national security priorities, budget constraints, and recruitment challenges. For example, the FY2008 NDAA (P.L. 110-181) lowered end-strengths for the Navy and Air Force from 2007 levels. In the late 2010s and early 2020s, as U.S. commitments in Iraq and Afghanistan diminished, Congress also reduced the Army's end-strength and increased that of the Navy. In the report (S.Rept. 118-58) accompanying the Senate Armed Services Committee–reported FY2024 NDAA (S. 2226 §401), the committee stated that it chose to recommend lower active end-strengths than requested because "legislating unreachable end strength numbers would set the military services up for failure" by "encouraging quantity over quality in recruiting." It remains unclear whether incremental reductions in previous years may have stemmed in part from this concern.

In other years, Congress has authorized end-strengths greater than those requested by the Armed Forces. For instance, in the FY2017 NDAA, Congress authorized an active Army end-strength that was 16,000 greater than the requested number.

In other instances, Congress sought increases in end-strengths. Via H.Rept. 110-146, for example, Members expressed concern over service proposals to retire legacy platforms and transfer certain roles to civilians. A second report (S.Rept. 110-335) accompanying the Senate-passed FY2009 NDAA (S. 3001) expressed the committee's support for "the Army and Marine Corps efforts to increase their active-duty end strength." Since the FY2022 NDAA (P.L. 117-81), Congress has authorized end-strength for the Space Force (See Figure 1).

Figure 1

. End Strength Trends, FY2001-FY2027

Figure is interactive in HTML report version.

' + this.series.name + ':

' + value + '

', shared: true, useHTML: true }, series: [{ name: 'Active Army', color: '#757048', legendcolor: '#757048', data: [ 480000, 480000, 480000, 482400, 502400, 512400, 512400, 525400, 532400, 562400, 569400, 562000, 552100, 520000, 490000, 475000, 476000, 483500, 487500, 480000, 485900, 485000, 452000, 445000, 442300, 454000, 469000, ], }, { name: 'Active Navy', color: '#0C90FC', legendcolor: '#0C90FC', data: [ 372642, 376000, 375700, 373800, 365900, 352700, 340700, 329098, 326323, 328800, 328700, 325700, 322700, 323600, 323600, 329200, 323900, 327900, 335400, 340500, 347800, 346920, 354000, 337800, 332300, 344600, 356500, ], }, { name: 'Active Air Force', color: '#C8102E', legendcolor: '#C8102E', data: [ 357000, 358800, 359000, 359300, 359700, 357400, 334200, 329563, 317050, 331700, 332200, 332800, 329460, 329600, 312980, 320715, 321000, 325100, 329100, 332800, 333475, 329220, 325344, 320000, 320000, 321500, 330400, ], }, { name: 'Active Marine Corps', color: '#7060A8', legendcolor: '#7060A8', data: [ 172600, 172600, 175000, 175000, 178000, 179000, 180000, 189000, 194000, 202100, 202100, 202100, 197300, 190200, 184100, 184000, 185000, 186000, 186100, 186200, 181200, 178500, 177000, 172300, 172300, 172300, 173700, ], },{ name: 'Active Space Force', color: '#0A0E10', legendcolor: '#0A0E10', data: [ null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, 8400, 8600, 9400, 9800, 10400, 13200, ], }], responsive: { rules: [{ condition: { maxWidth: 500 }, chartOptions: { legend: { enabled: true, layout: 'horizontal', align: 'center', verticalAlign: 'bottom' } } }] } //#### END container ####// }; new Highcharts.Chart("IAG-670606157", options); } } }); </script>

Source: CRS analysis of Congress.gov data and the President's budget requests from Office of the Under Secretary of Defense (Comptroller) for FY2001-FY2027.

Notes: FY2001-FY2026 data comprise authorized end-strengths from National Defense Authorization Acts. FY2027 data comprise requested end-strength in the President's budget request. Space Force end-strength from FY2020 and FY2021 is included in the Air Force line. Coast Guard, part of the Department of Homeland Security, is not shown.

FY2027 NDAA

The Department of Defense (DOD—which is "using a secondary Department of War designation" under Executive Order 14347 dated September 5, 2025) increased its FY2027 active-component end-strength request for all services by 40,100 over FY2026 authorized levels (see Table 1):

Army personnel increases would be concentrated in "multi-domain operational and fires-based capabilities (air defense, field artillery, cyber, and counter-UAS [uncrewed aerial systems]) that are critical to the success of the entire Joint Force."

Department of the Navy (which encompasses the Navy and Marine Corps) increases are aimed at providing "the expeditionary force necessary to promote America's interest [sic] around the globe."

CRS found no explanation for the Air Force's requested increase.

The Space Force's "mission growth matches the exponentially expanding contributions of the space domain to the American economy, and the warfighting requirements of the Joint Force."

The House-passed (H.R. 8800) and Senate committee-reported (S. 4784) versions of an FY2027 NDAA contained end-strengths identical to those requested by the executive branch (see Table 1).

Table 1. FY2026 and FY2027 Active Component End-Strengths

Service	FY2026 Enacted End-Strength	FY2027 President's Budget Request	H.R. 8800	S. 4784	Change from FY2026 Enacted to FY2027 Requested
Army	454,000	469,000	469,000	469,000	+15,000
Navy	344,600	356,600	356,600	356,600	+12,000
Marine Corps	172,300	173,700	173,700	173,700	+1,400
Air Force	321,500	330,400	330,400	330,400	+8,900
Space Force	10,400	13,200	13,200	13,200	+2,800
Total	1,302,800	1,342,900	1,342,900	1,342,900	+40,100

Source: Congress.gov; Department of Defense, Office of the Under Secretary of Defense (Comptroller).

Note: The Coast Guard, part of the Department of Homeland Security, is not shown.

Potential Issues for Congress

Considerations of the FY2027 NDAA may include discussions on end-strengths. Related issues Congress may debate may include the following:

How might these requests relate to the services' recruitment and retention efforts?
How might recruit quality goals be affected by the requested end-strengths?
How do these requests relate to service-level force restructuring initiatives, such as those underway in the Army and Marine Corps?
To what extent are these requests informed by the services' personnel requirements for current and planned efforts, such as the "Golden Fleet" and "Golden Dome"?
To what extent do these requests reflect national security priorities, as defined by Congress in statute and the executive branch in the National Security Strategy, National Defense Strategy, and other documents?
To what extent have these requests considered an optimum active component/reserve component force mix?
Does Congress have sufficient information to conduct effective oversight of DOD's efforts to formulate and achieve end-strength goals?