President Donald Trump said Wednesday that "tremendous medical costs" were partially behind his decision to bar transgender Americans from serving in the military. However, a report from The Washington Post showed that estimates for the cost of caring for transgender service members amount to just a fraction of what the military currently spends on erectile dysfunction drugs.

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The president did not provide any numbers to support his claim. However, the Post reported, a study commissioned by the Department of Defense and published last year by the Rand Corp. estimated that it would cost a maximum of $8.4 million per year to pay for transition-related care.

According to the report, the funds amount to "a 0.04 to 0.13 percent increase" in health care costs.

The American Medical Association said in a statement that there is “no medically valid reason to exclude transgender individuals from military service.”

“AMA policy also supports public and private health insurance coverage for treatment of gender dysphoria as recommended by the patient's physician,” According to the Rand study on the impact of transgender individuals in the military, the financial cost is a rounding error in the defense budget and should not be used as an excuse to deny patriotic Americans an opportunity to serve their country. We should be honoring their service - not trying to end it.”

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The Rand Corp. estimate amounts to about one-tenth of the amount the military spends each year on erectile dysfunction prescriptions, the Post reported.

A 2015 analysis of Defense Health Agency data by the Military Times showed the Department of Defense spent $84.24 million in 2014 on prescriptions for erectile dysfunction drugs.

In the period between 2011 and 2014, the newspaper reported, the military spent $294 million on erectile dysfunction prescriptions, "the equivalent of nearly four U.S. Air Force F-35 Join Strike Fighters."

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A separate study on the costs of transgender health care, published in 2015 in the New England Journal of Medicine, estimated that about 12,800 transgender troops were serving in the military and eligible for health care. The cost to provide transition-related care would amount to about $5.6 million annually, or 22 cents per member per month, according to the study.

Aaron Belkin, the study's author and director of the Palm Center research institute, wrote that, "Though my utilization and cost estimates are quite close to actual data provided by an allied military force, it seems clear that under any plausible estimation method, the cost amounts to little more than a rounding error in the military's $47.8 billion annual health care budget."

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White House deputy press secretary Sarah Huckabee Sanders said Wednesday afternoon that the decision to bar transgender people from service was a “military decision” made in the face of what the president saw as policy that “erodes military readiness and military cohesion.”

It was not immediately clear whether the ban would include people who are currently transgender and serving in the military. Sanders said the White House and Defense Department would work together to determine how to implement Trump’s plan.