KAISERSLAUTERN, Germany -- Thousands of airmen in both the officer and enlisted ranks could face involuntary separation starting next year as part of a series of force management programs, the Air Force announced Wednesday.

In addition, the Air Force said it will reduce the size of its civilian workforce by about 900 positions during the current fiscal year, though specific reductions by location have not yet been determined.

Air Force officials didn’t say how many airmen they plan to let go of next year. But over the next five years, the service needs to eliminate as many as 25,000 airmen slots, a reduction that’s being driven by the mandatory budget cuts known as sequestration, according to Air Force officials

“To be blunt, we are going to get smaller ... smaller than we’ve ever been as an Air Force,” Air Force leaders said in a signed letter emailed to airmen Wednesday night. “Over the next few years, we have to reduce our force by approximately 25,000 Airmen and as many as 550 aircraft if we do not receive any budget relief.”

The force management programs announced Wednesday will be both voluntary and involuntary. They include reductions in force for both officers and enlisted beginning in June and the implementation of several new involuntary force management programs, including a first-ever chief master sergeant retention board, according to an Air Force news release.

That board, which will convene in June, will consider the future employment status of chiefs in overmanned fields with 20 years of total active federal military service who do not apply for retirement before March 15.

“A chief’s retention board is new for the Air Force, and there are some understandable concerns,” said an Air Force news release, quoting Chief Master Sgt. Harold Hutchison of the Air Force Chief Master Sergeant Management Office. “Our sister services have successfully executed similar programs for years, and we are working closely with experts throughout the Department of Defense to ensure we implement deliberate processes.”

The Air Force will also convene a retention board in June for senior noncommissioned officers. The board will consider master sergeants and senior master sergeants for retirement.

Boards will be charged with identifying airmen for retention “who are consistently strong performers,” Brig. Gen. Gina Grosso, the Air Force force management policy director, was quoted as saying in a news release.

The Air Force in 2014 will once again offer early retirement, with close to full benefits, to officers and enlisted personnel in overstaffed career fields who have at least 15 years of service.

In the past when the Air Force had to thin its ranks, it typically announced voluntary measures first, officials said. Because of the narrow time frame this year, they’re announcing all programs at once to allow airmen to consider their options and to ensure their personnel records are up to date.

“Whether you choose to separate or are asked to separate, we are committed to doing everything that we can to help you and your family in your transition,” Air Force leaders said in the letter to airmen. It was signed by Acting Secretary of the Air Force Eric Fanning, Air Force Chief of Staff Mark Welsh III, and Chief Master Sergeant of the Air Force James Cody.