Washington has explicit insurance guidance on transgender-related health care.

Bulletins and Announcements:

• Guidance: Letter re: Transgender Health Nondiscrimination Protections
  Issued by: Insurance Commissioner Mike Kreidler
  Issued on: June 23, 2020
  Summary:

  This letter was sent to insurers in response to the announcement the Trump administration made that it intends to limit the protections transgender patients have under the Affordable Care Act. It was accompanied by a press release.

• Guidance: Letter to Health Insurance Carriers in Washington State
  Issued by: Washington Office of Insurance Commissioner
  Issued on: June 25, 2014
  Summary:

  “Reading the provisions of state law in conjunction with the definitions contained in Washington state’s Law Against Discrimination, and the requirements of the federal Affordable Care Act, it is clear that exclusions, prohibitions, and other forms of discrimination by issuers against policy holders who identify as transgender is prohibited.”