The Army stands to lose one-quarter of its general officers by the end of 2017, plus a quarter of its Senior Executive Service civilians by the end of 2018, under controversial organizational reforms approved by the U.S. Senate.

The bill also calls for a 25 percent reduction in the amount of money spent on contractors to do staff work and a reduction in the size of the National Security Council staff.

Because the Army has the most general officers, it has the most to lose under the proposal that is part of S. 2943, the Senate’s version of the 2017 National Defense Authorization Act. The Army has about 231 active-duty general officers today. That’s about 30 more than the Air Force, 70 more than the Navy, and 170 more than the Marine Corps.

Part of the reform would involve radically restructuring the military health care system in a way that severs the relationship between the Army and its medical department, a move the Obama administration says would jeopardize the readiness of the department to provide operational medical support. “It would also separate the accountability for medical support to military missions, and the responsibility for the quality of care from operational missions.”

Sen. John McCain, R-Ariz., the Senate Armed Services Committee chairman and chief advocate for the organizational reforms, said the bill “seeks to curb the growth in civilian staff and military officers that has occurred in recent years.”

“Over the past 30 years, the end-strength of the joint force has decreased by 38 percent, but the ratio of four-star officers to the overall force has increased by 65 percent,” McCain said. “We have seen similar increases among civilians at the Senior Executive Service level.”

The White House opposes the cuts, saying in a statement of administration policy that it supports simplifying the command structure but opposes a 25 percent reduction in general and flag officers. “Reductions to the number of general and flag officer positions could be made deliberately, after reviewing the role of each position and analyzing the impact of the reduction on the force,” the statement says. “Across-the-board mandated reductions would degrade the effectiveness and readiness of the force.”

On Senior Executive Service jobs, the White House says it eliminated 97 positions in 2011 and an additional 140 in the years since then but, as with general officers, wants to move in a “deliberate manner.”