June 30, 2016: The United States Department of Defense (DOD) adopts a policy permitting transgender people to serve in the military based on a nearly two year DOD review determining that there was no valid reason to exclude qualified personnel from military service simply because they are transgender.

July 26, 2017: President Trump tweets that “the United States Government will not accept or allow transgender individuals to serve in any capacity in the U.S. Military.”

August 9, 2017: NCLR and GLAD file Doe v. Trump, the first lawsuit filed to stop the ban, challenging its constitutionality and requesting that the court issue a nationwide preliminary injunction to stop it from taking effect while the case is being heard in court.

August 25, 2017: President Trump issues a memorandum ordering Secretary of Defense James Mattis to submit “a plan for implementing” the ban by February 21, 2018. Secretary Mattis delivers this (the “Mattis Plan” and panel report) to President Trump on February 22, 2018.

August 28, 2017: The ACLU files Stone v. Trump, challenging the Trump-Pence transgender military ban, in the United States District Court for the District of Maryland. On this same day, Lambda Legal files Karnoski v. Trump, challenging the Trump-Pence transgender military ban, in the United States District Court for the District of Washington.

September 5, 2017: Equality California files Stockman v. Trump, challenging the Trump-Pence transgender military ban, in the United States District Court for the Central District of California.

October 2, 2017: NCLR and GLAD join Equality California’s case, Stockman v. Trump, and file a motion for preliminary injunction.

October 30, 2017: The United States District Court for the District of Columbia rules that Doe v. Trump plaintiffs established a likelihood of success on their claim that President Trump’s ban violates equal protection, that plaintiffs would be irreparably harmed without a preliminary injunction to stop the ban, and that the public interest and balance of hardships weighed in favor of granting injunctive relief and temporarily halting the ban while the case is heard by the court.

November 17, 2017: The state of California is now a plaintiff in Stockman v. Trump, as the court grants California Attorney General Xavier Becerra’s motion to intervene.

November 21, 2017: United States District Court for the District of Maryland Judge Marvin J. Garvis issues a preliminary injunction in the ACLU’s case, Stone v. Trump.

December 11, 2017: United States District Court for the District of Washington Judge Marsha J. Pechman issues a preliminary injunction in Lambda Legal’s case, Karnoski v. Trump.

December 22, 2018: United States District Court for the Central District of California Judge Jesus G. Bernal issues a preliminary injunction in Stockman v. Trump.

March 23, 2018: President Trump accepts the “Mattis Plan” and issues a memorandum in which he “revoked” his August 25 Memorandum.

April 20, 2018: Defendants file a motion to dissolve the October 30 nationwide preliminary injunction enjoining the transgender military ban issued by the U.S. District Court for the District of Columbia; a motion to dismiss Plaintiffs’ Second Amended Complaint; and a Motion for Summary Judgment.

May 12, 2018: Plaintiffs file their cross-motion for summary judgment, as well as motions in opposition to Defendant’s motions to dissolve the injunction and dismiss Plaintiffs’ complaint.

August 6, 2018: United States District Judge Colleen Kollar-Kotelly denies Trump administration motions to dismiss Doe v. Trump and to dissolve the preliminary injunction preventing the ban from going into effect.

August 27, 2018: Defendants filed a notice of appeal to the D.C. Circuit Court of Appeals of Judge Kollar-Kotelly’s denial of their motion to dissolve the preliminary injunction preventing enforcement of the transgender military ban.

September 21, 2018: The Defendants-Appellants filed their opening brief in the D.C. Circuit Court of Appeals.

October 22, 2018: Plaintiffs-Appellees filed their opposition to Defendants’ appeal, asking the D.C. Circuit Court of Appeals to leave in place the preliminary injunction blocking enforcement of the transgender military ban.

October 29, 2018: A wide array of former military leaders, veterans’ and civil rights organizations, women’s groups, military scholars and historians, and states went on record opposing President Trump’s ongoing efforts to exclude transgender people from military service, in thirteen friend-of-the-court briefs filed in the United States Court of Appeals for the District of Columbia.

November 23, 2018: The Trump administration filed petitions for cert before judgment in Doe v. TrumpStockman v. Trump, and Karnoski v. Trump.

November 30, 2018: Judge Colleen Kollar-Kotelly forcefully denied the Trump administration’s motion to stay her preliminary injunction while the administration seeks cert from the Supreme Court.

December 10, 2018: D.C. Circuit Court of Appeals heard oral arguments on Defendants-Appellants appeal of the denial of their motion to dissolve the preliminary injunction.

December 13, 2018: The Trump administration filed petitions asking the U.S. Supreme Court to lift the injunctions blocking the ban from taking effect if the Court declines to hear the cases this term.

December 24, 2018: Plaintiffs filed briefs opposing the administration’s request that the U.S. Supreme Court hear cases on the ban prematurely.

December 28, 2018: Plaintiffs filed briefs opposing the administration’s request that the U.S. Supreme Court lift the injunctions blocking the ban from taking effect while the cases continue.

January 4, 2019: The U.S. Court of Appeals for the District of Columbia Circuit issued a per curiam order lifting the D.C. Federal District Court’s injunction blocking the Trump administration from enforcing its ban while the case against it proceeds.

January 22, 2018 – The Supreme Court denied the Trump administration’s request that it hear legal challenges to Trump’s transgender military ban this term, allowing the cases to proceed in the lower courts. In a separate order, the Court allowed the ban to go into effect temporarily while the cases against it proceed.