ALI VELSHI (HOST): At this point it’s coming down to cost and deployability. I want to just discuss what this concept is of deployability. The idea is that the defense secretary is going to be able to determine whether someone can be deployed, a transgender service member can be deployed. What does that involve?

ERIC FANNING: Well, I think it means two different things. The first is, is the service member going through any medical procedures that will prevent him or her from deploying? And we don’t have huge groups of transgender service members who are undeployable now, nondeployable now for that is reason, for that issue. Service members all the time find ways to schedule their personal needs, medical requirements around deployments. They join to serve. The second issue -- and we’ve answered this repeatedly, we’ve done the studies and analysis on it -- is are there ongoing medical treatments as a part of being a transgender service member that could prevent deployment, and there aren’t.

VELSHI: All right. So the ongoing medical treatments is important. In other words, if you are in the midst of transition, that requires medical care and that may affect deployability in the same way many other medical conditions would affect deployability.

FANNING: Absolutely. If you are pregnant, if you are sick with cancer, any number of medical issues. And we see service members do what they need to do to schedule that around, if at all possible, their commitment to serve.

VELSHI: When one is not deployable and maybe that is something that is going to be over a long period of time, what normally happens? Do they get an honorable discharge from the military?

FANNING: It depends on the condition, it depends how long it’s going to take. But first, the first reaction is we get them the medical care that they need. We don’t withhold medical care from service members who’ve made the commitment to serve their country.

VELSHI: Let's talk about the cost issue. There are a lot of numbers floating around, but according to RAND Corporation, which is a sort of a widely cited study, the added military cost of transgender care is about $8.4 million per year, which pales in comparison to the general military budget and the health care budget of the military. 

But there are numbers floating around that are much, much bigger. I've seen numbers in the billions and tens of billions of dollars. At some point I would assume that the military that has a handle on what things cost, would know what this cost is and would be able to determine whether or not it's incremental, it's small, it's big, it's relevant or not relevant. 

FANNING: Well, first of all, that 8.4 million number is the high end. It could be as low according to RAND as 2.4 million. RAND has done two studies on this. They're by far the most credible of organizations that have looked into this. I have seen no analysis whatsoever that supports any numbers in the billions. It just seems completely implausible to me. The RAND numbers show that maybe 29 to at a high of 129 service members will want transgender medical treatment while they're in uniform. 

Previously:

CNN military analyst: Trump's transgender military ban is a “broken” promise to troops who were told they could serve openly

Before Trump banned transgender people from serving in military, here's who praised him as pro-LGBTQ

Trump's trans military ban eschews years of research in favor of junk science from a hate group

Watch a transgender former Navy SEAL explain the disruption Trump's military ban on trans service members will have on the military