But the change could also affect some home security systems.
The FCC is calling this change the "Analog Sunset."
That's because the analog signal many cell companies use is now giving way to digital technology.
Most cell phone users won't even notice the change. But around the Valley alarm companies warn this digital adjustment has made them re-think the way they protect their customers.
Analog technology brought the cell phone industry to life back in the 80's, but on Monday it will become extinct.
Cell phone companies will use a digital signal exclusively which means analog dependent cell phones will go "dark."
Both At&T and Verizon officials anticipate this change will affect less than one percent of their customers. That could still mean thousands will have no service.
These major cell carriers have been warning customers for months to switch over to digital, even offering incentives.
Monday's switch will also affect alarm companies who offer home protection.
Jeff Stephens, General Manager of Valley Security and Alarm, says his company had to change the way they do business.
Jeff Stephens: "Everything has to be digital radios."
For the last 20 years Stephens, along with other security companies, have offered a back-up analog radio in case of a power failure.
These radios broadcast on the analog frequency to alert emergency crews.
With "Analog Sunset" on the horizon Stephens has rushed to replace out-dated radios with new digital ones. Jeff Stephens: "It does get a product out there for the customer that's more robust. It has less places that it can fail."
Stephens says digital signals can be more reliable than analog.
Jeff Stephens: "An analog signal takes up a fair amount of space and you can get a whole lot of digital signals in the same space taken up by that one analog signal.
That means more channels for an alert to reach police or fire crews and possibly save a life.
If you're not sure if this switch affects your alarm system, you should call your security company.
Also cell phone companies say if your phone has a color screen chances are your phone operates on a digital signal. However if you're still not certain contact your wireless provider.
You can get coupons to convert from analog to digital TV by going to www.dtv2009.gov.
