Prohibits health insurers, mutual benefit societies, and health maintenance organizations from applying categorical cosmetic or blanket exclusions to gender affirming treatments or procedures when determined to be medically necessary pursuant to applicable law and specifies a process for appealing a claim denied on the basis of medical necessity. Requires those entities to provide applicants and insured persons with clear information about the coverage of gender transition services, including the process for appealing a claim denied on the basis of medical necessity. (CD1)