May 1989 -- The Supreme Court rules that discrimination based on "sex stereotyping" -- such as denying a promotion to a woman because she's not feminine enough -- violates the Civil Rights Act of 1964.
1993 -- The Minnesota legislature amends the state human rights act to ban discrimination based on sexual orientation, including nonconformity to sex stereotypes.
March 2010 -- The Affordable Care Act (ACA), also known as Obamacare, becomes law. Section 1557 of the act bans discrimination based on sex and other characteristics in federally funded health care programs and activities. It does not explicitly interpret sex to include gender identity, but courts will interpret it that way in coming years.
April 2012 -- The Equal Employment Opportunity Commission rules that employment discrimination based on transgender status violates the Civil Rights Act of 1964. The decision from the Department of Labor's enforcement agency creates a precedent that is later applied to certain health care plans.
December 2012 -- The American Psychiatric Association approves an update to its diagnostic manual to eliminate gender identity disorder and replace it with gender dysphoria.
May 2014 -- Medicare lifts its decade-old ban on "transsexual surgery."
May 2016 -- HHS OCR issues a final version of Section 1557 clarifying that it forbids health care discrimination based on gender identity. All blanket exclusions for gender-affirming care must be removed from policies that HHS regulates by January 2017.
December 2016 -- A Texas federal court judge issues a preliminary injunction barring HHS from enforcing the gender identity provisions of section 1557's ban of sex-based discrimination. The anti-discrimination rule itself still stands.
February 2018 -- In an effort to address the "issues" that the Texas judge identified in his injunction, Department of Justice lawyers tell the court that HHS OCR submitted a draft of a proposed rule to the White House.
April 2018 -- HHS submits the draft proposed Section 1557 rule to the office of Management and Budget OMB for interagency review under Executive Order 12886, and informed the Franciscan Alliance court in its on April 16, 2018 status report.