Yam entered politics in the
2011 general election, contesting in
Chua Chu Kang GRC as part of a PAP team led by
Gan Kim Yong. He was elected and subsequently appointed Deputy Executive Director of the PAP in 2012, and Executive Director in 2013. In the
12th Parliament, he chaired the Defence and Foreign Affairs Government Parliamentary Committee (GPC), and also sat on the Culture, Community & Youth, and Social & Family Development GPCs. Yam co-sponsored a Private Member’s Bill with
Yeo Guat Kwang in 2014 to amend the Animals and Birds Act, strengthening animal welfare laws. In the
2015 general election, Yam was elected in the newly formed Marsiling–Yew Tee GRC, joining a team led by
Halimah Yacob and
Lawrence Wong. He has served as Chairman of the Marsiling–Yew Tee Town Council since 2015. He was elected to chair the new National Development GPC in the
13th Parliament and served on the Estimates Committee and the Culture, Community and Youth GPC. In 2018, he was appointed Assistant Organising Secretary of the PAP, and has been a member of its Central Executive Committee since 2020. Yam was re-elected in the
2020 general election. In the naming his new Cabinet, then-Prime Minister
Lee Hsien Loong appointed Yam as the mayor of the
North West District on 27 July 2020. He also became one of 5 District Chairmen in the PAP HQ Executive Committee. In the
2025 general election, the PAP team in Marsiling–Yew Tee GRC won with 73.46% of the vote. After the election, Yam was elected Chairman of the Culture, Community and Youth GPC for the
15th Parliament. ==Public service==