Enrolment happens through your employer
Foreign employees in mainland China are covered by the statutory employee social insurance scheme, and the enrolment is handled by the employer as part of the work-permit process. The five employee schemes are pension, medical, work injury, unemployment and maternity. You cannot enrol yourself individually in the employee scheme.
Social insurance agreements may change what you pay
Mainland China has social insurance agreements with a number of other countries. If your home country is party to one, certain contributions can be exempted or credited. This is decided per country and per agreement, so check the agreement that applies to your nationality and employment arrangement before you assume you owe a full set of contributions.
Where the statutory layer stops
Basic medical insurance reimburses a defined catalogue of items at designated institutions, subject to a deductible, a reimbursement rate and an annual cap. Private hospital rooms, advanced treatment, out-of-catalogue drugs and self-paid items sit outside it. That gap — not the routine part — is what commercial cover is for.
Order of payment
Social insurance settles first, commercial cover picks up what remains if its terms allow, and you pay what neither covers. The same expense cannot be recovered twice: insurance compensation follows the principle of actual loss.