The state had promised to refer inmate Shiloh Quine, then 56, to a surgeon and pay for the procedure as part of a 2015 settlement making the state the first in the United States to offer inmates a regular path to such treatment.
Quine, who is serving a term of life without the possibility of parole after convictions in 1981 for murder, kidnapping and robbery, had the surgery on Thursday, said Jill Marcellus, a spokeswoman for the Transgender Law Center, which negotiated the settlement.
Under its terms, the state agreed to allow inmates who are transgender or have gender dysphoria access to clothing, toiletries and other items consistent with their gender identities.
For those like Shiloh whose doctors agree that surgery is medically appropriate, the state will pay for the procedure. The cost was not specified.
Transgender Law Center Executive Director Kris Hayashi said that by providing Quine's surgery, the state was setting an example that would help others obtain needed care.
"For too long, institutions have ignored doctors and casually dismissed medically necessary and life-saving care for transgender people just because of who we are - with devastating consequences for our community," said Hayashi.
Under guidelines adopted in 2015 after the state's settlement with Quine, prisoners seeking to change their biological sex would need to be evaluated by medical and mental health professionals, and present their cases to a six-member committee of doctors, psychologists and psychiatrists.
Committee members would vote on whether the surgery was warranted, and a committee chair who is a medical administrator in the prison system would hold a tie-breaking vote.
They would also have to live for a year in their preferred gender roles and undergo hormone therapy.
Quine will be transferred to a women's prison after she is released from the hospital, said Terry Thornton, a spokeswoman for the California Department of Corrections and Rehabilitation.
