About 40 million Americans have mortgages serviced by escrow accounts. Yet escrow accounts are rarely covered by an explicit agreement between borrower and lender and are often poorly understood. As a result, escrow accounts have become the subject of growing controversy. Federal regulation of escrow accounts has become increasingly detailed and intrusive during the past two decades, and the subject is under almost continuous regulatory review. In the 1990s, the attorneys general of at least 10 states have sued large escrow account servicers over administration of accounts. The purposes of this article are to explain briefly how: escrow accounts work, benefit relevant parties, are regulated by federal agencies, and also to evaluate alternative regulatory programs. Most of the legitimate social goals of federal regulation could be achieved by requiring an explicit escrow agreement at the time of closing on a mortgage. A second-best requirement would be that interest be paid on escrow balances.