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.

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In 2011, "Don't Ask, Don't Tell" was repealed by the Obama Administration.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.