Social security for foreigners in Shanghai continues to be paid.

If when you first entered Shanghai, the male was under 50 years old/the female was under 40 years old, then a basic hukou was established when you entered Shanghai. When you reach the legal retirement age (currently 60 years old for men/50 years old for women), if your basic deposit account is still in Shanghai, and the last place where you have paid for ten years is also in Shanghai, then your pension application place is in Shanghai, and you can apply for a pension in Shanghai. When you reach the age and the accumulated payment period is over 15 years (including the payment period transferred to other insured places in this city and the continuous service before the end of 1992, the same below), then after you apply and are approved according to Shanghai standards, you can enjoy the monthly pension from the next month (this has nothing to do with your household registration at that time); Those who have reached the age of 15, but the payment period is less than 15, can apply for an extension of payment until they reach the age of 15 in Shanghai, and then apply for a pension.

Paying back the money is more troublesome. First, you need to find a company. If the company agrees, the company will come forward and pay for itself (of course, this is not in line with the regulations of Shanghai, and the company will also bear the risks). A few months is ok, but four years is a bit difficult. If you continue to pay now, Shanghai social security will be counted as 15 years when you retire. As long as you can pay 15 years before retirement, it doesn't matter if you don't pay back these four years. When you reach retirement age, social security has not accumulated to 15 years, and you can continue to pay delayed retirement after accumulating to 10 years.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.