First Chief Warrant Officer 2

Lindsey Muller spent most of her 16-year Army career as a man named Ryan. A bout two years ago, the AH-64 Apache Longbow pilot changed her name, started taking female hormones and underwent what the 34-year-old describes as "female puberty."

The biggest step in her transition came in 2014, when she confronted her commanders with the fact she is a transgender soldier who, under current Pentagon rules, has a "psychosexual condition" that warrants medical separation. "When I walked into their offices I had the current policy in my hand," Muller, a chief warrant officer 2, told Military Times. "I said ‘Hey, based on this regulation, I’m deemed unfit to serve. It was almost throwing myself at my commander’s mercy."

The commanders' response was unexpected. "I was encouraged to stay and continue my career," she said.

Muller, who works as a helicopter pilot instructor at Fort Rucker in Alabama, is one of at least 77 service members across the active-duty military who have notified their chains of command about their intent to change gender. Those troops — and potentially thousands of others — are eagerly awaiting a new Pentagon policy to clarify their status in the military and outline how a transgender service member might undergo a personal transition while conforming to military regulations.

Defense Secretary Ash Carter last year formed a working group to hammer out a new policy, which he said would be unveiled by this spring. Yet the issue has stalled amid high-level disagreement over the details, according to officials familiar with the Pentagon’s internal debate.

Many key questions remain . Allowing a service member to transition from one gender to another means wearing new uniforms, adhering to new grooming rules and aligning with the physical fitness standards linked to promotions. Who will decide when that transition is officially recognized? A commander? Health care professionals? The Pentagon bureaucracy’s personnel office? Individual service members?

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In addition the issue raises a host of medical issues. Will the military health care system pay for hormone therapy or sex- reassignment procedures? How much leave time will that warrant? Will any of those procedures impact a service member’s eligibility to deploy, fly or conduct other military missions?

"There has been progress in terms of trying to consider how to move forward and resolve this issue," Pentagon spokesman Peter Cook said last week . "There have been significant conversations within the building on that front."

But tension surrounding the issue was highlighted Wednesday, at the annual Pentagon "pride" event celebrating lesbian-gay-bisexual-transgender employees. Carter, who attended and spoke during the event last year, was absent, as were all of the military's most senior uniformed leaders.

The highest ranking official to speak at the event was Navy Secretary Ray Mabus. Newly appointed Army Secretary Eric Fanning, the Defense Department's first openly service secretary, also attended.

ARLINGTON, VA - JUNE 08: U.S. Navy Secretary Ray Mabus (L) talks to Army Secretary Eric Fanning (R) during a Lesbian, Gay, Bisexual and Transgender Pride Month Ceremony at the Pentagon June 8, 2016 in Arlington, Virginia. The Department of Defense held the event to celebrate the LGBT Pride Month. (Photo by Alex Wong/Getty Images)

Navy Secretary Ray Mabus, left, laughs with Army Secretary Eric Fanning during a the Pentagon's annual LGBT pride celebration June 8. Fanning is the Defense Department's first openly gay service secretary.

Photo Credit: Alex Wong/Getty Images

Studies suggest there are a more than 10,000 transgender service members on active duty and in the reserves . Recalling what she said was a slow, painstaking process to repeal the "Don’t Ask Don’t Tell" laws that prohibited homosexuals from serving openly, Muller said she is unsurprised to see the issue move so slowly.

"I tell you," she added, "the one thing the military has taught me is patience."

She recalls the slow and painstaking process involved in repealing the "Don't Ask Don't Tell" laws that prohibited homosexuals from serving openly.

Regardless of the Pentagon's policy, Muller has in many ways transitioned to being a female. "When I'm greeted at the gate in the morning on base its 'Good morning ma'am,'" she said.

She continues to wear a men's uniform and adhere to male grooming standards. She has applied for an exemption to those rules and permission to present herself publicly as a female, but that request stalled amid high-level uncertainly about the military-wide policy.

"So I don’t push the envelope, she said, "and I try to just remain androgynous."

Muller met Defense Secretary Chuck Hagel in 2014.

Photo Credit: Courtesy of Lindsey Muller

It’s easy to find videos online of transgender service members talking openly about their personnel experience. Last year, in fact, the White House invited Senior Airman Logan Ireland, a transgender service member, to an event and the Air Force granted special permission for Ireland, genetically a woman, to wear male military attire.

But the order all-but barring separation of transgender service members has created unusual situations to which many commanders are uncertain how they should respond. And treatment of transgender troops varies across the services and commands.

"In my opinion, they kind of put the cart before the horse. You can’t discharge transgender service members. But now the problem is: How do you treat a transgender person? This is very new territory," Muller said. "There really was no guidance on how far you can let a person go in transition."

Muller says she has encountered very few people who have a problem with her transition, and those who do express their concerns based on religion rather than personal animus.

And she's been heartened by the response from her command.

"To be honest, I could not have asked to work for a more professional group of leaders," she said. "When confronted with a difficult and never-before-dealt-with topic, they took into account my performance history and desire to continue serving, and I was encouraged to stay. Since then I have served openly as a transgender soldier rather seamlessly and with little to absolutely no conflict."