Former Health Minister Thapa is contesting elections for the second time, his constituency is Kathmandu-4. During the first CA elections, he was elected as a PR candidate from the Nepali Congress quota. During the second CA elections, he won the Kathmandu-4 seat with a landslide. He was also elected chair of Parliament's Agriculture and Water Resources Committee.

Born in Solokhumbu, Thapa started his political career with the Nepali Congress-affiliated Nepal Students Union. He was elected to the party's central committee by the 12th General Convention. During the 13th Convention, he was a candidate for the party's general secretary position. He was later nominated to the central committee by party chief Sher Bahadur Deuba.