Social Security is going plastic. A prepaid debit card for federal benefits is now available.

The Direct Express Debit MasterCard was designed to appeal to the nearly 4 million Social Security and Supplemental Social Security Income recipients who don't have bank accounts. Also, paper checks are more susceptible to delivery delays and theft; last year, 700,000 checks were lost or stolen.

Electronic payment of benefits also saves taxpayer dollars. ''It costs 88 cents more per payment to make a check payment versus an electronic payment,'' said Judith Tillman, commissioner of the U.S. Treasury's Financial Management Service. ''We're still making about 150 million check payments a year through paper checks.''

The card allows Social Security recipients to make purchases and withdraw money from an ATM just as they would using a debit card. Money on the card is FDIC-insured and the card would be replaced if lost or stolen.

The card also comes with conveniences such as free e-mail, telephone deposit notifications, low-balance notifications and the ability to check your balance.

There's no fee to sign up for the debit card and no monthly charges. Users are allowed one free withdrawal per payment from any of the network's 50,000 approved ATMs. After that, the withdrawals cost 90 cents. Out-of-network ATM surcharges might also apply. Monthly mailed statements also cost 75 cents each. If you lose more than one card, it will cost $4 each time.

However, the costs are small compared with the expense of check cashing. It could cost as much as 10 percent of the face value to cash a personal check and up to 1.5 percent of the face value to cash government and payroll checks, according to a 2007 report by the Federal Reserve Bank of Boston about the cost of being ''unbanked.''

Tillman is pleased with the roll-out's initial success, which has been advertised to recipients in 23 states and the District of Columbia [see accompanying story]. ''We already have over 52,000 people who have signed up for the card,'' she said, indicating the number surpasses the initial goal of 40,000 for the entire year.

This is the Treasury Department's second effort to bring Social Security recipients into the 21st century. A major public relations campaign aimed to inform recipients of the benefits of direct deposit helped to convert more than 2 million users the first three years of the campaign. That will save taxpayers $178 million over the next 10 years, Tillman said. Currently, 45 million, or 80 percent of beneficiaries, have their Social Security dollars deposited directly into their bank accounts. Tillman figures direct deposit is still the most convenient way for most Americans to receive their benefits.

The card is available to anyone receiving Social Security benefits through http://www.USdirectexpress.com or by calling 877-212-9991.