It's a legal battle that may signal a continuing shift in how society treats transgender individuals.

As reported by KSTP, 63-year-old Minnesota resident Evan Thomas has teamed up with the LGBT advocacy group, OutFront Minnesota, and the American Civil Liberties Union (ACLU) to sue the state over its lack of public insurance coverage for gender reassignment surgery. Both of the state;s current plans, MinnesotaCare and Medical Assistance, do offer counseling and hormone therapy for those suffering from gender dysphoria and who wish to transition, but the state has not covered surgical care since 2005 (though it has in previous years). Thomas, who first took advantage of testosterone hormone therapy in 2013, legally changed his name and gender earlier this year, but feels the coverage doesn't go far enough.

"For me this is an essential next step, and my doctors know this, we all know this, and at the same time here is the state just slamming this door in my face and saying no, you have to stop here, if you're in pain that's just too bad," Thomas told KSTP.

Gender dysphoria, as defined by the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM V), is the sensation that one's assigned gender at birth is incompatible with the one they identify as, to the point where that incompatibility causes great emotional distress and pain.

The modified definition is a subtle but distinct change from how the mainstream medical community once viewed transgender individuals. Previous versions of the DSM had a diagnosis called Gender Identity Disorder (GID), a label which many transgender activists felt depicted them as psychologically unstable or deranged. In recent years, however, new research illuminating the complex factors that may lead to gender dysphoria, including those neurobiological, has been presented.

Similarly, where once mental health professionals tried to convince or force transgender people to live their lives out as their assigned gender, the mainstream approach now attempts to help the individual cope with their dysphoria and/or transition to whatever degree they feel comfortable with. That said, gender reassignment surgery is commonly seen as the final, necessary stage of transition, and there are many who choose to hold off on it or decline to pursue it altogether. None of which is to say that transgender people still aren’t subjected to a myriad of discrimination, even from the medical world.

For Thomas, who had previously lived as a gender-nonconforming woman but was unable to entirely shake off his dysphoria-fueled depression, having the option to pursue surgery is vital.

"[W]ithout surgery, I can't escape the dissonance between my body as it is and the way my brain insists it should be," wrote Thomas on a Dec. 17 blog post for the ACLU announcing his lawsuit. "If I had a flat, firm chest instead of the weight and softness of breasts, I could hold my head up and stand tall and proud. I could look in the mirror and be at peace with my own image. I could, maybe, learn to love my whole self."

Currently, only 10 states and Washington, D.C. offer public health insurance coverage for gender reassignment surgery, though legislation seeking to overturn Minnesota's ban has been introduced and is waiting to be debated by its House of Representatives. The U.S. Health and Human Services are currently discussing a similar federal proposal for Medicare.