He served as a Member of Parliament for Wangsa Maju representing People's Justice Party (PKR) of Pakatan Harapan coalition between 2013 and 2018.
A medical doctor by profession, Tan graduated from University of Malaya and worked in United Kingdom during 1977 and 1981.
He then worked for two years in Southern Sudan, practising community medicine with a voluntary Christian NGO.
[6] He later returned to Malaysia and started a private clinic on Jalan Tuanku Abdul Rahman in Kuala Lumpur.
[3] In 1995, he joined Gerakan two month before the general election and Tan Sri Dato' Alex Lee nominated him as a candidate in the new created parliamentary seat of Segambut.