1996 ‘Welfare Reform’ signed by Bill Clinton
Establishing a Five Year Lifetime Limit on Assistance: To address long-term welfare dependency, TANF placed a five year lifetime limit on assistance, but allowed states to exempt up to 20 percent of such cases for hardship reasons. States are allowed to reduce this lifetime limit below 5 years, and almost half of the states have done so.
Eligibility for TANF assistance is limited to pregnant women and families with children. Within these constraints, however, TANF allows states broad discretion in how they spend their federal block grant money.
Imho, that's a part of the reason why the government wants to control 1/6 of the US economy by taking over “health care”. And it is also the reason they are encouraging illegal immigration (need more workers to pay for SS). There is some benefit and/or payoff/profit to be had by the US government that will enable them to kick the can down the road a little longer.