S&Ls went through many changes in the late 20th cent., primarily due to deregulatory measures instituted in the 1980s by the U.S. federal government, allowing them to offer a much wider range of services than ever before. The deregulatory measures allowed S&Ls to enter the business of commercial lending, trust services, and nonmortgage consumer lending. The Depository Institutions Deregulation and Monetary Control Act of 1980 began these sweeping changes, one of which was to raise deposit insurance from $40,000 to $100,000. Many contend that this extension of insurance coverage encouraged S&Ls to engage in riskier loans than they might otherwise have sought.

Two years later, the Depository Institutions Act gave S&Ls the right to make secured and unsecured loans to a wide range of markets, permitted developers to own S&Ls, and allowed owners of these institutions to lend to themselves. Under the new laws, the Federal Home Loan Bank Board (FHLBB) was given a number of new powers to secure the capital positions of S&Ls. The FHLBB allowed S&Ls to print their own capital, and escape charges of insolvency through such measures as "goodwill," in which customer loyalty and market share were counted as part of a capital base. As a result, an S&L that was technically insolvent could resist government seizure.

S&Ls began to engage in large-scale speculation, particularly in real estate. Financial failure of the institutions became rampant, with well over 500 forced to close during the 1980s. In 1989, after the FSLIC itself became insolvent, the Federal Deposit Insurance Corporation took over the FSLIC's insurance obligations, and the Resolution Trust Corporation was created to buy and sell defaulted S&Ls. The S&L crisis ultimately cost the government some $124 billion. The Office of Thrift Supervision was also created, in an attempt to identify struggling S&Ls before it was too late, but the largest S&Ls were among the institutions at the core of the financial crisis of 2008.