In terms of Social Security, the program isnu2019t a Congressional appropriation. Congress sets the benefit formula, but by an large Congress appropriates almost nothing to Social Security.Technically, the revenue collected for SS and Medicare from the taxation of benefits is considered an appropriation. That is 50 billion or so a year.Social Security is financed with payroll taxes. When SS collects a dollar of payroll taxes, it makes a promise to that worker of future benefits. It is financed, not much different from going to a bank and taking out a loan.The Trust Fund holds excess and invests excess cash. It only pays for benefits when the financing revenue is not sufficient. It is an important distinction: Social Security is not paid out of a Trust Fund. It was intended to be paid from a Trust Fund, but Congress changed the program to a pay-as-you-model over the 1940s and 1950s. The distinction is important because it is the genesis of the systemu2019s problems.