District of Columbia has explicit insurance guidance on transgender-related health care.
Bulletins and Announcements:
Bulletin: Bulletin 13-IB-01-30/15 Prohibition of Discrimination in Health Insurance Based on Gender Identity or Expression (2013)
Issued by: District of Columbia Department of Insurance, Securities and Banking
Issued on: March 15, 2013
Exclusions for services related to sex reassignment violate DC's prohibition on discrimination based on gender identity or expression and are no longer enforceable.
Updated on Feb 23, 2020