The US military has yet to offer Pte First Class Chelsea Manning sex change treatment despite medical recommendations, her lawyer has said.
Defence secretary Chuck Hagel approved treatment for a condition known as gender dysphoria in July.
But lawyer David Coombs says her requests for hormone therapy and other accommodations have been "ignored".
The soldier formerly known as Bradley Manning is serving a 35-year sentence for leaking secret files to Wikileaks.
"This time last year I publicly asked that I be provided with a treatment plan, to bring my body more in line with my gender identity," Pte Manning said in a statement to NBC News.
"Unfortunately, despite silence, and then lip service, the military has not yet provided me with any such treatment."
Hair and grooming
She adds that despite legally changing her name in April, she is not referred to as Chelsea at the military prison in Fort Leavenworth, Kansas, where she is currently held.
"In my daily life I am reminded of this when I look at the name on my badge, the first initial sewed onto my clothing, the hair and grooming standards that I adhere to and the titles and courtesies used by the staff," Pte Manning said.
The Pentagon has not yet responded to a BBC request for comment.
Pte Manning was a low ranking intelligence analyst known as Bradley and living as a man when she leaked a vast trove of secret US military and diplomatic documents to the anti-secrecy website Wikileaks.
She was arrested in 2010 and jailed under harsh conditions. Last year she was tried in a court martial and found guilty of espionage, theft and violating computer regulations.
On 22 August 2013 - one year ago - she announced through her lawyer that she wanted to live as a woman, declaring, "I am Chelsea Manning. I am female."
Pte Manning has been diagnosed by military doctors with gender dysphoria, the sense of one's gender being at odds with the sex assigned at birth.
Threat to sue
The US military is required to offer medical treatment to its soldiers, but Pentagon policy prohibits transgender people from serving openly in the military.
Pte Manning will not be discharged from the military until she has finished her prison term.
Chase Strangio, a lawyer with the American Civil Liberties Union (ACLU) representing Pte Manning, told the BBC there had been "no action" taken by the military on the treatment issue.
Pte Manning was only promised "rudimentary treatment" by the military, Mr Coombs told the BBC and they "have not spelt out what it is".
Mr Coombs has said the military's knowledge of Pte Manning's gender dysphoria dates back to April 2010, when the soldier sent a supervisor an email titled "My Problem" and attached a photo of herself dressed a woman.
He and the ACLU sent a letter to the military last week demanding she start treatment "consistent with the recommendations of her treating doctors and an outside expert who evaluated her".
If the military does not "adequately respond... we are prepared to pursue litigation to vindicate her constitutional rights" Mr Coombs added.