Pfc. Bradley Manning: "I am fa emale." (Patrick Semansky/AP)

Pfc. Bradley Manning declared Thursday morning that she was a female, and intended to seek hormone therapy  in prison.

“I am Chelsea Manning. I am female,” the private wrote in a statement. “Given the way that I feel, and have felt since childhood, I want to begin hormone therapy as soon as possible. I hope that you will support me in this transition.”

Right now, Army policy suggests there's a lot of space between requesting hormone therapy and actually receiving it. At the same time, recent case law might make Manning's argument a bit stronger, after other inmates have successfully petitioned their facilities for treatment.

Manning was sentenced to serve 35 years at Fort Leavenworth Prison, a military prison in Kansas. A spokeswoman for the facility has already told the "Today Show" that "the Army does not provide hormone therapy or sex-reassignment surgery for gender identity disorder."

In response, Manning's lawyer, David Coombs, told the same program that, "If Fort Leavenworth does not, then I'm going to do everything in my power to make sure they are forced to do so."

If Coombs does seek legal action, it wouldn't be unprecedented. The United States Bureau of Prisons recently faced challenges to its policy of only providing hormone therapy to an inmate if that person had received such care prior to incarceration.

"Where inmates have been denied care, courts have said that's unconstitutional," says Jennifer Levi, director of the Transgender Rights Project at Gay and Lesbian Advocates and Defenders. "I don't know of any cases that have been brought yet against military prisons. But they would have the same obligation to provide adequate medical care."

Levi worked with a North Carolina inmate to reform federal policy on hormone replacement therapy in prison. Vanessa Adams entered a North Carolina facility at age 29. She was biologically male but "self-identified as female throughout her adult life," according to court documents.

"Because of this, she wanted to initiate the gender transition process prior to her incarceration, but found herself unable to do so in the face of the restrictions imposed on her by a conservative family and workplace," the lawsuit continues. Adams had been diagnosed with gender identity disorder; Manning has also received the same diagnosis.

Adams filed a lawsuit in 2009 after her prison denied treatment. That suit was settled outside of court two years later, with one prong of the settlement being a change to prison policy, allowing hormone therapy treatment to start in prison.

In May 2011, the Bureau of Prisons sent a memo to its wardens outlining a new policy that all inmates seeking hormone replacement therapy "Receive a current individualized assessment and evaluation. Treatment options will not be precluded solely due to level of services received, or lack of services, prior to incarceration."

Manning's prison sentence doesn't fall under this policy. Military prisons are part of the Defense Department, not the Bureau of Prisons.

Outside of the prison system, private insurance plans have increasingly begun to cover these types of services. The number of companies getting a perfect score on the Human Rights' Campaign's ranking of transgender-inclusive benefits grew from 85 in 2011 to 207 in 2012.