Government shutdowns do not impact Social Security checks, but other services, like benefit verifications and card issuance, would be disrupted.
According to the Committee for a Responsible Federal Budget, many federal government agencies and programs rely on annual funding appropriations passed by Congress. Social Security, Medicare, and Medicaid are mandatory spending programs, which aren't subject to annual appropriations. This means the government would continue to send out payments for social security recipients and people who Medicare and Medicaid cover. But other services, like benefit verifications and card issuance, could be disrupted during the shutdown. Moreover, only essential services and mandatory spending programs continue to operate during the government shutdown.
The Social Security Administration (SSA) stated that Social Security checks are financed through a dedicated payroll tax. Any additional revenue generated by taxes is deposited into trust funds set aside for future Social Security payments. Those funds won't be depleted until 2033. Even during a government shutdown, the SSA would have enough money to cover administrative costs and make timely payments. However, the Administration's operational employees are paid through appropriate funds.
According to Article I, Section 9 of the U.S. constitution, "No money shall be drawn from the Treasury except in Consequence of Appropriations made by Law." The Antideficiency Act reinforces this. This act forbids federal officials from spending funds before an appropriations bill has been passed. However, there are some exceptions for "emergencies involving the safety of human life or the protection of property."
In the event of a government shutdown, security checks would be protected.