Nearly one-fifth of the 4,000 Regular Army captains screened by retention boards that met in September are being put on notice they will be involuntarily separated or retired later this year.

The 740 affected officers, all captains of the Army Competitive Category, Nurse Corps and Medical Service Corps, will be notified between now and Feb. 25 of their pending release by a general officer or other senior leader in their chain of command.

Separations and retirements will occur not later than Dec. 1, and will contribute to the end-strength reductions slated for fiscal 2016 and 2017.

Under the drawdown plan recently submitted to Congress, Regular Army endstrength, which currently stands at about 480,000 soldiers, is slated to hit 450,000 by Sept. 30, 2018.

In announcing the results of the captain retention boards, Lt. Gen. James McConville, Army personnel chief, said, "We must implement drawdown levers to reach the approved endstrength."

McConville earlier told Army Times, "If we can avoid involuntary separations we will, but the behavior of the force kind of drives us on what we can do.

"We brought in almost a thousand extra officers during the Grow the Army phase, and those officers are now captains and their year groups are overstrength," he said.

Officers who were selected by the retention boards, and who are deployed or serving in a combat zone, will be redeployed to their home installation for transition processing.

Those who are stationed overseas, such as in Korea or Europe, will be given the opportunity to return to a stateside post, according to Army officials.

The target populations for the separation and early retirement boards that met in September were basic-branch captains in year group 2009, and select cohorts of Army Medical Department officers.

Similar boards that met in 2014 selected nearly 1,200 captains and 550 majors for separation and early retirement.  The target year groups for captains were 2006 through 2008, and cohorts 1999 through 2003 for majors.

Additional retention screenings will be held later this year for lieutenant colonels, chief warrant officers five and possibly captains.

McConville noted that while it is Army policy to only look at captain and major year groups once for separation and early retirement, officers will go through annual promotion reviews at those ranks that could result in involuntary separation.

The September retention screenings involved two types of boards, one for separation, and one for early retirements.

Officers who were selected by an Officer Separation Board, and who have at least 15, but fewer than 20 years of active federal service may request retirement under the provisions of the Temporary Early Retirement Authority, commonly known as the 15-year early retirement plan.

Most officers who do not qualify for TERA, and who have at least six years of active service, qualify for separation pay, a one-time entitlement calculated by multiplying 10 percent of an officer's annual basic pay times years and partial years pf service.

Enhanced Selective Early Retirement Boards, or eSERBs, were for officers who are eligible for retirement, and who were within two years of reaching 20 years of service on the convening date of the board.

These officers will be retained on active duty until reaching 20 years of service, unless they request an earlier release.