Troops with 16 or more years of service will no longer be permitted to transfer their Post-9/11 GI Bill benefits to a spouse or child starting next year, Defense Department officials announced Thursday.

Currently, troops who serve a minimum of six years and commit to serving an additional four years are eligible to transfer the education benefit to their dependents. Some who agree to the four years but are barred from completing it, such as troops who are injured and medically discharged, are permitted to keep the transfer. Others who start the process after getting injured can request a waiver so the transfer can go through.

But starting July 12 of next year, troops will need to start the GI Bill benefit transfer process between six and 16 years of service, the policy update states.

The goal, Pentagon officials said in a release, is to shift the benefit to focus on retention.

"After a thorough review of the policy, we saw a need to focus on retention in a time of increased growth of the armed forces," Stephanie Miller, director of accessions policy in the Office of the Secretary of Defense, said in a statement. "This change continues to allow career service members that earned this benefit to share it with their family members while they continue to serve."

Related: Post-9/11 GI Bill Transferability Update Questions Answered

Although the benefit is authorized by law, how the Pentagon uses it is a matter of policy. A 2015 report from the congressionally mandated Military Compensation and Retirement Modernization Commission (MCRMC) noted that the benefit is meant to be used as a retention tool, not as an entitlement.

The updated policy mirrors that stance.

"Transferability is neither an entitlement nor a transition or readjustment benefit," the policy states. "The Military Departments will not automatically approve a service member's request to elect to transfer benefits."

Troops who are involuntarily separated through a "force shaping" event will be able to keep the transfer even without serving their additional obligation, the policy states. The new policy does not address service-specific transfer waivers for wounded warriors or others who start the transfer process after being injured.

Officials first warned such a change could be in the works during a hearing on Capitol Hill late last year.

"The Department of Defense intends to issue a policy change to the 'Post-9/11 GI Bill' regarding the transferability of benefits to eligible family members," Anthony Kurta, acting deputy under secretary of defense for personnel and readiness, told members of the Senate Armed Services Committee in a written statement.

"Effective one year from this change, the ability to transfer benefits will be limited to service members with less than 16 years of total service," he wrote.

Defense officials noted in the policy that this will likely not be the last time transferability is altered.

"DoD will continue to track recruit quality and retention metrics carefully, so as to adjust policy and force management tools to support any major shifts in recruitment trends," it says.

This isn't the first time post-9/11 GI Bill transferability has seen policy changes. In early 2013, the Army issued a policy barring soldiers named for involuntary separation from starting the transfer.

In July of the same year, the Defense Department changed the policy to require every service member who wanted to make the transfer, including those who were eligible for retirement, to commit to an additional four years of service.

-- Amy Bushatz can be reached at amy.bushatz@military.com.