The site reports that the openly gay Allen will appear in three episodes of the nighttime program, the first airing September 23, as Eric, a patient in need of a liver transplant, and who develops a relationship with first-year resident Kyle (played by Adam Grimes) while undergoing treatment.

"We're delighted to have Chad join our show because not only is he a remarkable actor, he's an amazing activist," according to head writer Sri Rao. "I welcome the honesty and the authenticity that he will bring to our show."

Allen recently appeared on stage in The Little Dog Laughed. He is best known for his starring role on Dr. Quinn, Medicine Woman and his other TV credits include a series of mysteries in which he plays Donald Strachey, including Third Man Out and On The Other Hand, Death.