After leaving office as prime minister, he served as ambassador to the United States from 2014 to 2016 and as chairman of the board of the Eurasian Economic Commission from 2016 to 2020.

In 1987 Tigran Sargsyan received his PhD at Leningrad Financial and Economic Institute, where he defended his thesis titled "Regional social-economic development planning on Armenia's example".

In 1994 Tigran Sargsyan studied at the Faculty of "Law-making Activity," in the International Law Institute, Washington, D.C., United States.

In 1993–1995 Tigran Sargsian was elected as a member of the Supreme Council of the Republic of Armenia within "National Democrats" fraction headed by Shavarsh Kocharyan.

Together with the chairman of the Central Bank of Isaac Isaakyan and Finance Minister Levon Barkhudaryan, Tigran Sargsyan was appointed as a co-chairman of the State Commission for regulation of currency, created by the Supreme Council of the Republic of Armenia on 13 October 1993.

ARCA also became a platform for the operations of Mastercard, Visa, American Express and Diners Club, using a single processing center, technology and software solutions.

In the future regulatory framework it was possible to adjust the process of tracking the turnover of criminal assets in banks and credit organizations, as well as the funds used to finance terrorist activities or money laundering.

Two months following the appointment of Sargsyan Russo-Georgian War bursts out which seriously hurt economy of Armenia blockaded by Turkey and Azerbaijan for more than 20 years, and 70% of imported products are from Georgia.

[14] The next year after Sargsyan government start, second wave of the global financial crisis reached Armenia, which led to 14.1% fall of GDP.

Commenting on the Economic collapse Tigran Sargsyan said: "The Housing bubble that was inflated, burst, causing negative phenomenon".

[18] In frames of anti-crisis measures development to infrastructure projects, building of roads, schools and hospitals was carried out around Armenia.

[18] According to World Bank report, government anti-crisis program prevented helped poverty level fall to 51.7%.

[18] Since 2008 Tigran Sargsyan government initiated negotiations with Asian Development Bank about financing of highway that would connect north and south of Armenia.

4-lane highway with total length of 556 km was planned to lead through Agarak – Kapan – Yerevan – Gyumri – Bavra, connecting Iran to Georgia.

At first stages electronic document flow was launched at Yerevan Municipality, Central Bank, as well as Mulberry system, which in 2011 included 35 state institutions.

System made it possible for citizens to check processing of their applications and documents, as well as watching activity of government, budget expenditures, etc.

[18] In April 2010 the new energy block of Yerevan Thermal Power Station was launched, built with support of Japan Bank for International Cooperation.

Severe protests were also organized against launching new compulsory pension funding system,[34] which finally didn't come into force while he headed government due to his resignation in April 2014.

However, he had previously offered to resign a month earlier, but was convinced to stay on in the role by the president until a Constitutional Court ruling on his controversial pension reform plan[35] that had been criticised.

The measure would have required Armenians born after 1973 to contribute five percent of their monthly income to one of two private funds sanctioned by the government and the Central Bank to manage the pensions.

As ambassador Tigran Sargsyan actively attended international forums and conferences on economic policy, Eurasian integration and cooperation issues.

Under his active participation on 10 March 2015 the European Institute organized a special round-table-discussion entitled "Eurasian Economic Union: Armenia’s accession and beyond".

The event was attended by Tatiana Valovaya – Eurasian Economic Commission Minister of Integration and Macroeconomic Development, ambassadors of Russia and Kyrgyzstan in the US, representatives of the US State Department, diplomatic reps, members of social and political circles.

A new position was launched – board member (minister) on internal markets, informatization, information-communication technologies, which was occupied by Armenia's Karine Minasyan.

[54] Since 2016 public statements were made by Ashot Grigoryan, head of "EU-ASIA Business Finance Centre" firm (registered in Slovakia), against Tigran Sargsyan, accusing him of stealing $300 mln from Nairit Plant.

[citation needed] In response to the statements, Tigran Sargsyan filed a lawsuit against Grigoryan and a number of news agencies, demanding a refutation.

[55] In August 2018 Ashot Grigoryan signed Memorandum of understanding with Artsvik Minasyan, then minister of Economy of Armenia, ahead of promised investments.

[56] In October 2018 24news.am news agency published journalist investigation, revealing fact that companies belonging to Grigoryan, including the "EU-ASIA Business Finance Centre", had no turnover the years prior to that, and banking accounts were empty.

[57] Also a fact was revealed that Ashot Grigoryan claimed to have a scientific "Doktor nauk" degree and was a professor at Yerevan State University.

[58] On 14 May 2019, after two years of litigation, the General Court satisfied the lawsuit of Tigran Sargsyan and ordered Ashot Grigoryan to publish a refutation of the false charges, as well as pay 1 million dram fine.