CHAS

This distinction saves confusion later: CHAS applies at participating GP clinics, so it can reduce the cost of the visit where you ask for a referral. The hospital developmental assessment is subsidised separately — through the standard Citizen/PR subsidy at public hospitals, which you get by arriving with a polyclinic or GP referral.

So the sequence is: (subsidised) GP or polyclinic visit → referral letter → subsidised assessment at KKH DCD or NUH CDU. The full sequence, with costs and waits, is in How to get an autism diagnosis in Singapore.