BOSTON (AP) -- A federal appeals court has upheld a judge's ruling granting a taxpayer-funded sex change operation for a Massachusetts transgender inmate serving a life sentence for murder.

Michelle Kosilek, who was born a man, was convicted in the 1990 murder of wife Cheryl Kosilek.

Kosilek sued the Massachusetts Department of Correction after prison officials refused to grant her request for sex-reassignment surgery. A federal judge ruled in 2012 that the surgery is the "only adequate treatment" for Kosilek's gender-identity disorder.

Kosilek now lives as a woman in a men's prison.

State prison officials appealed the ruling to the 1st U.S. Circuit Court of Appeals. The court ruled Friday that the 64-year-old Kosilek is entitled to the surgery.