Commissioners voted 3-1 to require manufacturers to add the tuners to all TV sets with screens of 36 inches and larger by July 2004, while the requirement for smaller sets would be phased in over the following three years.
Congress has mandated that the nation switch to digital TV, which offers clearer pictures and better sound. But the transition to this new technology has been delayed by reluctance within the industry to make the switch before most households can receive digital signals.
"This action will take these electronic appliances from being HDTV (High Definition Television) ready to HDTV reality," said Michael Powell, the commission's chairman.
Powell rejected industry complaints that the action would force consumers to pay more for television sets, saying the price of digital tuners would drop quickly as they are mass produced.
The dissenting vote came from Commissioner Kevin Martin, who noted that most TV viewers no longer receive their signals over the air and therefore do not need digital tuners.
"I believe the cost of this particular proposal outweighs the benefits," Martin said.
Commissioner Kathleen Abernathy said the requirement was necessary to move the switch to digital TV forward.
Without this requirement, "the transition remains stalled," she said. "There's no question in my mind."
In advance of Thursday's decision, Jenny Miller, a spokeswoman for the Consumer Electronics Association, had said, "We believe there's going to be a mandate for the inclusion of a digital broadcast television tuner in all television sets."
But she also said she felt the manufacturers might challenge such a ruling in court, if necessary.
Miller said the requirement would cost $250 for each set, amounting to an annual "TV tax" on the industry and consumers of about $7 billion. She said that with most consumers receiving television signals by cable or satellite, putting the tuner in all TVs would make people pay for a device most won't use.
Broadcasters, who need consumers to be able to receive their digital signals, support a requirement for the tuners. They call the manufacturers' cost estimates "outlandish and ridiculous."
"We don't think consumers will see any cost increase," said Dennis Wharton, a spokesman for the National Association of Broadcasters. "The simpler you make it for consumers — you build the features into the set — the faster you get to consumer acceptance of this new technology."
He said digital tuners are especially important to give people access to digital broadcasts from local stations not carried by cable or satellite.
The broadcast industry says 455 television stations are now broadcasting digital signals in markets that include nearly 90 percent of the nation's TV households. But they say less than 1 percent of the 25 million sets sold each year have digital tuners.
Congress is requiring most broadcasters to convert by 2006 from existing analog technology to more efficient digital television, which allows much more programming and data to be transmitted over one channel. Broadcasters were given second TV channels for free to do so.
When the switch is complete, broadcasters must return their analog channels to the government for other uses.
Digital TV development has stalled over a number of issues, including the limited availability of high-definition programming and the pricey equipment needed for viewers to see it.
Cable and satellite service providers also have balked at allocating additional space for digital programming, while local TV stations struggle with the cost of converting to digital signals.