WASHINGTON - More than 4 million Social Security and Supplemental Security Income recipients who don't have bank accounts will soon have the option of getting a prepaid MasterCard debit card with their benefits instead of a paper check.

That would mean that those without bank accounts won't have to use expensive check-cashing facilities or carry around large amounts of cash, the Treasury Department said yesterday.

"This is a more sure, more reliable, cost-free and cost-effective way for people to get their money," said Treasury spokeswoman Judith Tillman.

The cards can be used just like regular debit cards, allowing recipients to get cash, pay bills and make purchases anywhere MasterCard debit cards are used. Each FDIC-insured card will have its own personal-identification number for use at ATMs and in stores, and if lost or stolen it can be replaced.

Tillman said that switching to debit cards from paper checks could save as much as $42 million for taxpayers.

Just like the 40 million people who get their Social Security benefits directly deposited into their bank accounts, debit-card recipients will no longer have to worry about their checks being stolen or lost in the mail because the government will automatically transfer their benefits to their cards at the beginning of the month.

There were 700,000 reports of lost or stolen checks last year, Tillman said.

Using the card can be free, the Treasury Department said, because there are no signup fees, and bank accounts or credit checks are not required. However, some transactions will have a cost, like ATM withdrawal fees.

However, the Treasury Department suggests getting around those fees by getting cash back with purchases at stores or by making free cash withdrawals through bank tellers.

"It's an opportunity to manage your money for free," Tillman said.

The cards will be made available this summer, but people can start signing up for them now.

The Social Security Administration also will allow people to ask for debit cards when they apply for their benefits starting this fall, Tillman said.

About 50 million people receive retirement, survivors and disability benefits from Social Security. *