BIF. A unit of the Federal Deposit Insurance Corporation (FDIC) which provides deposit insurance to non-thrift banks. The focus of the BIF is to separate the administration of banks and thrift insurance companies, though it also increased the deposit insurance of commercial and savings banks to $100,000. Both the Bank Insurance Fund and the Savings Association Insurance Fund were formed in 1989 in response to the savings and loan bailout. The two funds were merged into the Deposit Insurance Fund in 2005.