According to http://www.dtv.gov/consumercorner.html#faq9
How can I be sure that I am buying a digital TV (DTV)?
By law, beginning March 1, 2007, all television reception devices (including TVs, VCRs, DVRs, etc.) imported into the U.S. or shipped in interstate commerce must contain a digital tuner. Retailers may continue to sell analog-only devices from existing inventory, but must prominently display on or near the analog-only device a Consumer Alert label with this advisory:
What is the difference between “Integrated” DTVs and DTV or HDTV “Monitors”?
An Integrated DTV set is a television with a built-in digital tuner (also referred to as “a DTV”). A digital tuner is also sometimes called a DTV decoder or DTV receiver. If you have an Integrated DTV, you will not need any additional equipment, with the exception of a broadcast antenna (either a rooftop antenna or “rabbit ears” connected to the set), to receive over-the-air digital broadcast programming. Integrated DTVs can also receive and display analog broadcast programming, so you can continue watching analog broadcasts.
In contrast, a DTV Monitor is not capable of receiving digital broadcast programming without additional equipment; it is simply a display device without the processing capability for DTV reception. A digital or HD set-top box must be connected between the antenna and the monitor to receive and display over-the-air digital or HD programming.
If you have a digital or HD “Monitor” and would like to purchase a digital or HD set-top box to view over-the-air programming, confirm with your retailer that the set-top box is compatible with your Monitor.