SAVANNAH, Ga. (AP) — A transgender fire chief has filed a federal discrimination lawsuit against the small Georgia city where she led the fire department for more than a decade, then was fired 18 months after she began coming to work as a woman.

Rachel Mosby says her firing last summer by the city of Byron not only cost her wages and retirement benefits, but also tarnished her reputation. The lawsuit filed Tuesday in U.S. District Court in Macon says city officials fired Mosby “based on her sex, gender identity, and notions of sex stereotyping.”

Mosby's June 4 termination letter cited poor job performance and made no mention of her gender transition.

The U.S. Equal Employment Opportunity Commission has treated LGBT-based job discrimination cases as illegal sex discrimination since 2013. The could end if the U.S. Supreme Court decides firings and harassment based on a worker's sexual orientation or gender identity don't qualify as sex discrimination under the Civil Rights Act.

The Supreme Court heard cases on that issue Oct. 8. Its ruling is still pending.

A city of about 4,500 in a farming region outside Macon, Byron hired Mosby as its fire marshal in 2007. The city established its first professional fire department a few months later and promoted Mosby to fire chief in January 2008.

The lawsuit says Mosby spent years growing the department, obtaining grants to pay for equipment and improving its rating, which insurers use to help assess a community’s fire risk.

Mosby started coming to work as a woman in January 2018, more than a year after she began a medical transition. At first, city hall colleagues and administrators were supportive, she said, but it didn’t last long.

“They didn’t want somebody like me in that position, or any position with the city,” Mosby told The Associated Press in a September interview.

After making her transition public, Mosby said, she was ordered to start wearing a uniform the first day she came to work in a skirt. Previously, Mosby often wore suits and ties. Some city officials insisted on referring to her using male pronouns, according to the lawsuit. When Mosby fired a reserve firefighter who called the chief a slur to her face, the firefighter appealed and was reinstated by the city.

In January 2018, Byron’s City Council changed its personnel policy to eliminate appeals for any department heads the city fires. Derick Hayes, Byron’s city administrator, fired her that summer.

Hayes cited three reasons for Mosby’s firing in her termination letter: that she was responsible for a backlog of business licenses awaiting approval; that she attended only five classes at a recent fire chief’s conference, wasting the city’s money; and that she failed to maintain certification as an arson investigator.

Mayor Michael Chidester said by email Tuesday that he had not seen Mosby's lawsuit. He denied her allegations that she was fired because of her transition.

“It has been the contention of the City since claims were filed with the EEOC that such claims had and have no basis in fact,” Chidester said.

Mosby's lawsuit says the EEOC took no action after reviewing a complaint she filed last year with the agency, which then gave her permission to go to court on her own.

If the Supreme Court rules that the Civil Rights Act doesn't prohibit discrimination based on sexual orientation or gender identity, Mosby's lawsuit won't be entirely gutted.

She also claims discrimination under the Americans with Disabilities Act, saying the work backlog cited in her termination letter resulted in part from doctor visits and physical therapy appointments to treat back and hip problems caused by a job-related injury.