Social security can be paid for two years (24 months) at most, which means that it is calculated from the month of payment (it is calculated according to the time period of payment, not according to the cumulative month). For example, this month is any time period from April, 1 to April, 29, and it is counted as one year. For example, any time period from April, 1 to March, 29 to April, 28 is calculated as two years, and only September, 28 is paid separately. In 2 years, if you need to pay back social security, you can pay back according to the social security pension insurance payment formula. The personnel who have established personal accounts directly submit the overdue declaration to the handling institution and choose the payment standard; Those who have not established personal accounts shall make a supplementary declaration at the same time when applying for insurance registration by the handling institution, and choose the payment standard. Apply for institutional review and payment. If the application meets the requirements, print the business application form and submit it to the applicant for signature and confirmation. If the audit fails, print the receipt for handling and submit it to the applicant. Medical insurance must accumulate a certain payment period (including deemed payment period) when it retires. Generally, it is stipulated that 15 years for women and 2 years for men, which is the minimum payment period, and the retirement age is pushed forward by 15 or 2 years without interruption.