Transgender people and military service
The policy of inclusion was reportedly still in effect in 2017.

South Africa: Since 1998, South Africa allowed transgender individuals to serve in the South African National Defence Force (SANDF). It became the first and currently the only African country to do so.

Sweden: As of 2014, Sweden allowed transgender people to serve openly in its military forces. The policy of inclusion was reportedly still in effect in 2017.

Thailand: In Thailand, males 21 years of age and above can serve voluntarily for six months in the military. If they opt not to if they got selected in the annual draft lottery they must serve for two years.
Transgender women/kathoeys are not exempted and are still legally required to show up for the military conscription event on draft day regardless of their transition status or presentation. Identity documents can't be legally changed in the country. Those who have undergone sex reassignment surgery (SRS) and those who are deemed to have taken up "a female appearance" are automatically exempted from being drafted. Those who have a "male appearance" would have to undergo a medical test to get an exemption.
Those who underwent SRS are exempted for the next two years while those diagnosed with gender identity disorder are exempted for life.
As a result, on draft day, lines of people awaiting processing may include transgender women in makeup and feminine attire, waiting along with the male draftees. Contrary to the wide impression of acceptance of transgender women in Thailand, many complain about being treated as second-class citizens, and of the stress of being undressed or publicly humiliated. Some transgender women were still drafted.

United Kingdom: As of 2014, the United Kingdom allowed transgender people to serve openly in its military forces. The policy of inclusion was reportedly still in effect in 2017.

United States: The United States' military policy previously allowed for exclusion of transgender people from service on medical grounds. While cisgender gay, lesbian, and bisexual service members were allowed to serve openly since 2011, transgender service members risked discharge if they did not pass as their assigned sex. This required that service members conceal their gender identities throughout service.
It was estimated that in 2008–2009 there were approximately 15,500 transgender individuals either serving on active duty or in the National Guard or Army Reserve forces within the U.S. Military.
A 2016 study based on previous research estimated that only between 1,320 and 6,630 transgender individuals served on active duty and between 830 and 4,160 in reserve duty, with midrange figures of 2,450 in active duty and 1,510 in reserves. Regardless of how many transgender individuals are members or veterans of the United States Armed Forces, transgender individuals are between 2-5 times more likely to serve in the military than their cisgender (non-trans) counterparts, primarily due to the provision of both financial security and a sense of belonging to a community. These reasons contribute to the belief that the United States Armed Forces is one of the largest, if not the largest, employer of transgender Americans.
A key controversy and concern for transgender service members is the use of military medical services to transition from one gender to another.
Different administrations' policies since 2016 regarding transgender people and military service has varied, as described in the summary below:

Barack Obama administration: On 22 August 2013, the day after her sentencing at an Army court-martial, U.S. soldier Chelsea Manning issued a public statement declaring herself to be a transgender woman. In 2014, while incarcerated in the United States Disciplinary Barracks, Manning filed a lawsuit against Secretary of Defense Hagel for failing to provide appropriate medical treatment necessary for her gender transition. In a military first, hormone therapy to assist with Manning's gender conformity was approved in early 2015 and added to her treatment plan along with other provisions such as cosmetics and female undergarments.
Air Force Secretary Deborah Lee James openly supported a change to the military's transgender policy, stating in 2014 that it was likely to be reviewed in the next year or so. In February 2015, Secretary of Defense Ashton Carter stated he was open minded about including transgender people in the military and that nothing but individual lack of merit should preclude such people from service. Carter's statement was later endorsed by President Obama.
On 19 August 2015, Carter stated in a memo that the Defense Department had begun the process of dismantling the ban and that transgender people would be able to openly serve in the U.S. military by 27 May 2016. Department of Defense regulations that ban transgender persons from US military service were repealed on 30 June 2016. Beginning on that date, otherwise qualified United States service members could not any longer be discharged, denied reenlistment, involuntarily separated, or denied continuation of service because of being transgender.

Donald Trump administration: On 26 July 2017, US President Donald Trump announced that transgender people would no longer be allowed to serve in the US military. The following day, General Joseph Dunford, Chairman of the Joint Chiefs of Staff, stated that openly transgender people will continue to be allowed to serve until Trump provides direction to James Mattis, the Secretary of Defense.
The Palm Center released, on 1 August 2017, a letter signed by 56 retired generals and admirals opposing the proposed ban on transgender military service members. The letter stated that if implemented, the ban "would cause significant disruptions, deprive the military of mission-critical talent and compromise the integrity of transgender troops who would be forced to live a lie, as well as non-transgender peers who would be forced to choose between reporting their comrades or disobeying policy".
On 9 August 2017, five transgender United States military personnel sued Trump and top Pentagon officials over the proposed banning of transgender people from serving in the military. The suit asks the court to prevent the ban from going into effect. Two major LGBT-rights organizations filed a petition in the United States District Court in Washington on behalf of the five transgender service members.
Trump signed a presidential memorandum, dated 25 August 2017, directing the Secretary of Defense and Secretary of Homeland Security to submit an implementation plan by 21 February 2018, to reinstate the ban and halt the use of military funds for "sex reassignment surgical procedures for military personnel". On 30 October 2017, US District Judge Colleen Kollar-Kotelly barred the administration from excluding transgender people from military service in Jane Doe v. Trump, but did not address whether federal funds should be used to pay for sex reassignment surgery for service members. The ruling also stated that as far as could be seen, "all of the reasons proffered by the president for excluding transgender individuals from the military in this case were not merely unsupported, but were actually contradicted by the studies, conclusions and judgment of the military itself".
In November 2017, the Defense Health Agency for the first time approved payment for sex reassignment surgery for an active-duty US military service member. The patient, an infantry soldier who is a trans woman, had already begun a course of treatment for gender reassignment. The procedure, which the treating doctor deemed medically necessary, was performed on 14 November at a private hospital, since US military hospitals lack the requisite surgical expertise. On 11 December, Kollar-Kotelly ruled that the government must accept transgender recruits into the military by 1 January 2018. After the ruling, the Department of Justice appealed to the United States Court of Appeals for the District of Columbia Circuit to issue a stay on the district court's ruling. The Pentagon confirmed on 26 February 2018 that the first transgender recruit had signed a contract to join the military.
On 23 March 2018, President Trump banned transgender and transsexual people with current or previous gender dysphoria from serving in the U.S. military. However, the Pentagon said they would comply with the court decision until it is reversed. The policy was stayed in Karnoski vs. Trump (Western District of Washington) on 13 April 2018, when the court ruled that the 2018 memorandum essentially repeated the same issues as its predecessor order from 2017, that transgender service members (and transgender individuals as a class) were a protected class entitled to strict scrutiny of adverse laws (or at worst, a quasi-suspect class), and ordered that matter continue to a full trial hearing on the legality of the proposed policy.
On 22 January 2019, the US Supreme Court allowed President Trump's transgender military ban to go into effect while the ban was litigated in lower courts. On 12 March 2019, acting Deputy Defense Secretary David Norquist signed a directive to allow Trump's policy to take effect in 30 days.

Joe Biden administration: On Biden's first day in office, his press secretary, Jen Psaki, announced in a press conference that the President would soon reverse the government's ban on transgender people from serving openly in the military, though a specific date for this action was not announced. Although Biden had originally said that reversing the ban would be an action taken "on day one", this had been unable to happen due to the fact that his nominee for Secretary of Defense, Lloyd Austin, had still not been confirmed yet.
On 25 January 2021, President Biden signed an executive order to reverse the ban, allowing most transgender individuals to serve in the United States military. The order also required the United States Department of Homeland Security to lift its transgender service ban as well.