In 1973, Maryland became the first state in the United States to legally define a marriage as between a man and a woman and ban same-sex couples from marrying. However, there were cases of marriages outside the state being recognised.

Until 1973, there was no law explicitly banning same-sex marriage in Maryland, however there was also no legal recognition provided to same-sex couples.

In 2015, Maryland allowed for legal gender recognition but required medical documentation.

In 2006, Maryland provided legal gender recognition but required proof of surgery.

Before 2019, Maryland did not legally recognize a third gender.

Maryland's state legislature passed and the governor signed the Anti-Discrimination Act of 2001, prohibiting discrimination on the basis of sexual orientation in employment. It took effect in October of that year.

Before the Anti-Discrimination Act of 2001, no laws at the federal or state level prohibited discrimination against LGBT people in employment.

From July 6, 2025 onward, Coast Guard Reserve and Regular Coast Guard service members who were eligible for voluntary separation but did not elect or complete it, and who either have a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria and do not receive a waiver, or have a history of cross-sex hormone therapy or sex reassignment or genital reconstruction surgery in connection with a sex transition, are placed into the involuntary administrative separation process.

From June 7, 2025 onward, Active Guard Reserve, Marine Corps Active Reserve, Regular Air Force, Regular Army, Regular Marine Corps, and Regular Space Force service members who were eligible for voluntary separation but did not elect or complete it, and who either have a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria and do not receive a waiver, or have a history of cross-sex hormone therapy or sex reassignment or genital reconstruction surgery in connection with a sex transition, are placed into the involuntary administrative separation process.

On May 8, 2025, the United States Department of Defense (USDoD) began initiating administrative separation proceedings for service members who had already identified themselves for voluntary separation before March 26, 2025. On the same date, it reinstated the ban on transgender enlistment by directing that applicants who have a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria and do not receive a waiver, or who have a history of cross-sex hormone therapy or sex reassignment or genital reconstruction surgery in connection with a sex transition, are denied entry into military service.

On May 9, 2025, the USDoD ended all surgical procedures related to sex reassignment for service members with gender dysphoria. All such procedures—whether planned, scheduled, or not yet scheduled—were canceled, and any previously approved SHCP waivers for these surgeries were revoked. New waiver requests are no longer processed, except in cases involving the necessary treatment of surgical complications, which require special review.

Service members aged 19 or older who were already receiving cross-sex hormone therapy prior to this memorandum may continue treatment temporarily if a provider deems it necessary to prevent harm, but only until their separation is completed. Moving forward, USDoD funding cannot be used to initiate any new hormone therapy treatments for gender dysphoria, though military department leaders may request case-by-case exceptions for non-surgical care if needed to protect a service member’s health, subject to review and approval.

Also on May 9, 2025, the USDoD directed military educational institution libraries to use a standardized set of subject-heading searches to identify post-2010 books potentially associated with “gender ideology,” transgender-related topics, and other targeted concepts, sequester those materials from normal access by May 21, 2025, and hold them for expert review and possible later disposition.

On May 15, 2025, the United States Coast Guard resumed implementation of its transgender service policy by immediately pausing new accessions for individuals with a history of gender dysphoria and pausing planned, scheduled, or unscheduled medical procedures related to gender transition.

By May 21, 2025, the US Naval Academy had returned all but about 20 of the 381 books removed on March 31–April 1, 2025, to its shelves, while US Air Force libraries, including the US Air Force Academy, had also pulled a few dozen books for review.

On June 5, 2025, the U.S. Coast Guard formally made members and applicants with gender dysphoria who did not receive a waiver ineligible for service and subject to separation or disqualification, while allowing temporary continuation of some preexisting hormone therapy until separation.

On June 6, 2025, US Coast Guard restored the Civil Rights Awards Program after completing a review and updating the Civil Rights Manual.

On the evening of March 18th, U.S. District Judge Ana Reyes blocked the implementation of Trump's executive order banning transgender people from the military. The judge said that not only was the order unconstitutional but “a solution in search of a problem.”.

On January 27th, 2025, President Trump signed an executive order that bans transgender people from serving in the military.
On February 10th, 2025, Secretary of Defense Pete Hegseth filed in court a memo relating to President Trump’s executive order from the previous month.

From then until March 18th, 2025, The U.S. military prohibited transgender individuals from enlisting and ceased providing or supporting gender transition procedures for service members.

In 2021, former President Joe Biden removed then-former President Donald Trump’s ban on transgender people serving in the military.

The Trump administration enacted a new policy barring individuals with a "condition" known as "gender dysphoria." from serving in the military.

In 2011, "Don't Ask, Don't Tell" was repealed by the Obama Administration. Former President Obama allowed members who were dishonorably discharged under DADT, to receive an honorable discharge.

Don't Ask, Don't Tell was the historic compromise signed by President Bill Clinton authorizing people who are LGBT to serve in the military provided they didn't disclose sexuality. The law also removed the ability for others in the military from asking for a service member's orientation.

From May 19, 1941 until September 20, 2011, LGB people were banned from enlistment and service in the United States Army, US Coast Guard, US Marine Corps, and US Navy, and, beginning September 18, 1947, in the Air Force. From October 1, 1982, to September 19, 2011, when homosexuality was the sole basis for separation and no aggravating circumstances were present, the characterization of service was determined by the member’s overall record and could be Honorable or General (under honorable conditions), with entry-level cases receiving an uncharacterized separation.

By May 17, 1963, in the United States Army; by 1982, in the United States Air Force; from March 31, 1986, on a U.S. Department of Defense-wide accession basis covering the United States Army, United States Navy, United States Marine Corps, and, by agreement, the United States Coast Guard; by August 12, 2005, in the United States Navy and United States Marine Corps; and by April 29, 2011, in the United States Coast Guard, transgender people were banned from enlistment and service until open service was authorized on June 30, 2016.

By February 22, 1956, in the United States Coast Guard; by February 10, 1961, in the United States Army; by January 11, 1962, in an Air Force-specific accession standard; from March 31, 1986, on a Department of Defense-wide accession basis covering the Army, Navy, Marine Corps, Air Force, and, by agreement, the Coast Guard; and, from December 20, 2019, in the United States Space Force through inherited Air Force and DoD standards, applicants with intersex-related conditions identified in military rules as “hermaphroditism,” and later as “hermaphroditism, pseudohermaphroditism, or pure gonadal dysgenesis,” were disqualified from accession under military medical standards.

The FDA announced changes to the blood donor eligibility policy in April 2020, reducing the MSM deferral period from 12 months to 3 months. The change came amid the beginning of the COVID-19 pandemic, where blood was needed urgently.

After a series of recommendations, the FDA has moved to a 12 months deferral.

Starting in 1983, the United States implemented a full ban on blood donations from gay men. The primary justification for the ban was the perceived high risk of HIV transmission, with health regulators identifying men who have sex with men (MSM) as a significant risk to the safety of the blood supply.

Before 2018, there was no law in Maryland that banned conversion therapy.