There were big fears inside the Pentagon throughout the past year: Transgender teens will be lining up outside recruiting stations; the military services will see an influx of first-term enlistees seeking sex-change operations; the new policy offering health care for gender dysphoria would make the U.S. military the most popular employer among transgender people.

But none of that is likely to happen, according to experts inside and outside the military.

The new policy unveiled Thursday by Defense Secretary Ash Carter promises to provide health care for transgender troops, which could in some cases include gender reassignment surgery. But that same policy includes a several key provisions that will restrict coverage for first-term enlistees and discourage young transgender people from joining the military if they are primarily motivated by the new coverage.

More importantly, it's flawed to think that transgender people now will head in droves to the nation's recruiting stations , experts say.

"The argument is, frankly, insane," said Aaron Belkin, an advocate for transgender troops with the Palm Center in California.

"Let's just use common sense. It's so much easier to join a civilian firm that offers the same coverage. Or just move to San Francisco," he said, noting that the city of San Francisco offers free gender-transition-related health care to any city residents who do not have a health insurance policy that covers it.

Concerns about a surge in transgender enlistment was widely discussed among Defense Department officials developing the new policy, according to several sources familiar with those talks .

The issue is addressed specifically in the official Department of Defense Instruction issued with Carter’s announcement.

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The 180-day rule

Questions about gender dysphoria will become part of the standardized questionnaire for new military recruits. Recruiters will reject anyone with a history of gender dysphoria unless a doctor certifies that the individual has been treated and "stable" for a minimum of 18 months.

Any new first-term enlistees who seek treatment for a new diagnosis of gender dysphoria will likely be kicked out of the military promptly based on standard rules that all recruitment standards apply for the first 180 days. After that 180-day window passes, first-term enlistees seeking gender dysphoria treatment might face questions about whether they knew and withheld medical information at the time of enlistment, according to a senior defense official.

"After 181 days, the question would be ‘Did they reasonably know when they came in? And if they did reasonably know — and they were hiding a significant medical fact — that then could be a basis for termination for erroneous or fraudulent enlistment," the defense official said. "That is a consideration. So you don’t have safe harbor just because you got beyond the 180 days ."

Even if there is no evidence of fraudulent enlistment, the policy suggests commanders can order major medical treatment to be postponed.

"The all-volunteer force’s readiness model is largely based on [first-term enlistees] being ready and available for multiple training and deployment cycles," the policy says . "This readiness model may be taken into consideration by a commander in evaluating a request for medical care."

The Pentagon policy aims for consistency across the force and will discourage commanders from mounting overly aggressive investigations of people who lodge new claims of gender dysphoria. Commanders can consult with their medical advisers, legal advisers and the special "coordination cells" that will be set up to clarify transgender policy issues.

"We expect our commanders to deal with tough issues all the time, and this is another circumstance where they are going to deal with tough issues and make judgment calls. This is no different," the defense official said.

Estimating the real impact

The number of troops seeking care is likely to be very small. A study published in the New England Journal of Medicine estimates it will be fewer than 200 each year from a total force of 1.3 million active duty troops.

Pentagon officials estimate the total cost of that health care coverage to be between $4 and $14 million, a small sliver of the Defense Department's total health care budget of about $60 billion.

In the private-sector, some insurance companies extend coverage for gender transition care at no additional cost . Studies show transgender coverage actually reduces insurance companies' overall expense by reducing the need for other treatments, such as metal health care or substance abuse treatment.

Transgender advocates note, too, the military's compensation package and enlistment standards will be the same for all prospective recruits.

"We use health care benefits to entice people to join the military all the time," Belkin said.

"If they are not good candidates for military service, they are going to get weeded out in the accessions process."