The American Medical Association on Monday said there is no valid medical reason to ban transgender persons from serving in the U.S. military.

The powerful physicians group, with nearly 220,000 members, voted on a resolution saying not only should transgender people be allowed to serve, they should be provided health services at the same medical standards that apply to nontransgender personnel.

The vote comes on the heels of an Air Force announcement last week that gave decision authority for involuntarily separating transgender troops to the director of the Air Force Review Boards Agency.

The move, similar to one instituted by the Army in March, is seen as taking the decision from commanders, who may apply a personnel policy banning transgender service arbitrarily and placing it with officials who can review the evidence and make consistent decisions, according to Daniel Sitterly, principal deputy assistant secretary of the Air Force for manpower and reserve affairs.

Until last year, Defense Department Instruction 1332.18, Disability Evaluation System, specifically listed transgender identity as a "congenital or developmental defect" that mandated administrative separation.

But the policy was amended in August, dropping a list of mental health conditions that require automatic separation. At the time, a Pentagon spokesman said the change was made because the list was not comprehensive but its elimination did not affect actual policy.

But since the change, both the Air Force and Army have moved to ease restrictions on military service for transgender personnel.

According to an Air Force release issued June 4, neither gender dysphoria nor self-identification as transgender are circumstances that warrant involuntary separation.

A psychiatrist or doctoral-level clinical psychologist must weigh in on the matter, and commanders must prove the condition interferes with duty requirements or performance before a service member can be separated.

The repeal of the "don't ask don't tell" policy in 2011 allowed gays and lesbians to serve openly in the military, but DoD accession policy still bars transgender individuals from enlisting or being commissioned in the military.

The Army's standards of medical fitness policy for accession continue to list transgender and gender dysphoria as conditions that make prospective troops "administratively unfit" for duty.

The Navy and Marine Corps physical standards for enlistment or commissioning list gender identity disorders as disqualifying if they interfere with safety and reliability or foster a perception of impairment.

The Air Force Recruiting Service instruction notes that applicants are ineligible if they have a history of transexualism and/or other gender identity disorders.

The Coast Guard policy bars anyone with certain mental health disorders, including gender dysphoria, from serving if "in the opinion of the civilian or military provider," it interferes with or prevents satisfactory performance of military duty.

More than 15,000 transgender individuals serve in the military, according to the Transgender Military Service Commission.

At least 18 countries, including Canada, New Zealand and Australia, allow transgender troops to serve openly.

Aaron Belkin, director of the Palm Center, a San Francisco think tank that promotes research on gay, lesbian and transgender issues in public service, said evidence is mounting that the Pentagon's transgender ban is unsound.

"The military's transgender exclusion policy is sustained by claims that transgender individuals require more burdensome medical care in the field than other members of the military," Belkin said. "AMA has now joined a chorus of expert voices showing this assertion to be false."

Retired U.S. Public Health Service Rear Adm. Alan Steinman, the former director of Coast Guard health and safety, argued in favor of the AMA resolution at the annual meeting, taking place this week in Chicago.

"It's a positive step that the AMA has recognized that transgender men and women have the same ability to function in high-stress military environments as any other qualified service members," Steinman said.