The coupon plan for purchasing digital-to-anlog converters is part of final rules for a $1.5 billion subsidy program issued by the Commerce Department's National Telecommunications and Information Administration (NTIA). Congress initially appropriated $990 million for the program. If initial funding runs out, another $510 million could be made available if NTIA certifies to Congress that coupon requests exceeded the initial amount.

The program is designed to ensure that households that do not receive broadcast signals from cable or satellite services will be able to continue receiving over-the-air broadcasts after the February 2009 transition to all-digital programming.

NTIA said consumers requesting coupons must "self-certify" to the agency that they do not already subscribe to a cable or satellite provider.

Retailers will sell the converter boxes. NTIA said the coupons will be distributed in a form of similar to gift cards so that each converter box purchase can be verified at a retailer's sales terminal.

The agency said it would identify eligible converter boxes that can be sold by retailers. Those boxes must comply with technical specifications included in the final rule. Manufacturers will be required to submit production boxes and test results to the Federal Communications Commission for certification, NTIA said.

"With the coupon program and a successful analog-to-digital transition involving the public, industry and government, the switch from analog to digital television will be completed as planned," John Kneuer, assistant secretary of commerce for communication and information, said in a statement.

Some lawmakers complained that NTIA had been slow to issue the new rules governing the converter box subsidy program.