In 1975, Htin Kyaw joined the Ministry of Industry 2 as a Deputy Division Chief. In 1980, he was appointed as a Deputy Director in the Foreign Economic Relations Department, Ministry of Planning and Finance, and resigned from government service in 1992. He was arrested on 22 September 2000, and spent four months in Insein prison for assisting Aung San Suu Kyi's trip outside Yangon. From 2012, he worked as a senior executive for Daw Khin Kyi Foundation, founded by Aung San Suu Kyi and named after her mother Khin Kyi. Though not a veteran member of the NLD, Kyaw worked very closely with Aung San Suu Kyi at the Office of NLD Chairperson. He was mentioned as a possible presidential pick after the NLD won a sweeping victory in the 2015 general election. Aung San Suu Kyi was constitutionally barred from the presidency, since her late husband and both of her children are British citizens; the constitution does not allow a president, his parents, his spouse, or his children to "owe allegiance to a foreign power." Upon his nomination, Aung San Suu Kyi said she had chosen him for his truthfulness, loyalty and respectable education.
Presidency
On 10 March 2016, he was nominated as one of the Vice Presidents of Myanmar by the NLD for the House of Representatives. On 11 March 2016, 274 MPs out of 317 voted him as one of the Vice Presidents. On 15 March 2016, 360 MPs out of 652 of the Assembly of the Union voted him as the President, ahead of Myint Swe and his party colleague Henry Van Thio. in New Delhi On 17 March 2016, Htin Kyaw proposed a cabinet of 21 ministries. On 21 March 2016, he delivered a speech in the Assembly of the Union for the first time regarding the proposal of the formation of ministries and the MPs of the Union Parliament approved it. On 30 March 2016, Htin Kyaw was sworn in as President of Myanmar, becoming the first president since U Nu's overthrow in 1962 to have no ties to the military. Despite Htin Kyaw being a nominally independent leader, Aung San Suu Kyi said that she would in fact direct the actions of the president and lead the country through him. It was thought before the elections that Aung San Suu Kyi would "be above the president” and make all key decisions. Indeed, the post of State Counsellor–equivalent to a Prime Minister–was created for her. On 21 March 2018, amid speculations of ill health, it was suddenly announced that Htin Kyaw had resigned from his position as president, citing health issues and the 'need for rest'. Myint Swe, first Vice President of Myanmar, succeeded Htin Kyaw as President under the constitution of Myanmar, which also called for a new President to be selected by the Pyidaungsu Hluttaw within seven days of Htin Kyaw's resignation. in Presidential Palace
Htin Kyaw writes under the pen nameDala Ban, a prominent title of ancient Mon commanders. He wrote a biographical book about his father Min Thu Wun: The Father’s Life: Glimpses of my Father . He also wrote various articles about his family life with his father in weekly journals.
Health problems
Htin Kyaw went to Bangkok in September 2017 to have medical examinations taken and to be given necessary treatment. There has been speculations about his ill health among people but they were denied by officials. He departed to Singapore on 23 January 2018 to have a medical check-up.