Help me analyze the social security in Chengdu.

1. Participating in social security means social security for the insured, including pension and medical security.

2. If the insured reaches retirement age and the accumulated social security contribution is less than 15 years from the date of insurance payment, he can continue to pay. If the accumulated payment period is not reached, it can be paid in one lump sum.

3. Social security can participate in pension and medical care at the same time, or it can only participate in pension without medical care; But you can't just participate in medical care and not participate in old-age care.