"TAP is revolutionary because it's more than just a fare payment card," said Mayor Antonio Villaraigosa, who chairs the MTA board. "It's a system that will make transit easier and better for our riders as Los Angeles' public transportation system continues to expand."
The rechargeable cards, which have been used in other cities for decades, will be sold at vending machines.
Coins and bills will still be accepted on MTA buses and trains, even after the TAP conversion comes, MTA officials said.
By late January, the 400 retail outlets that sell monthly MTA passes will be selling the TAP cards exclusively. Elderly, student and other patrons who receive discount passes will be eased into the program and transitioned to TAP cards by next June.
MTA is spending $89 million to upgrade obsolete fare boxes on buses and to turnstiles and improved fare collection gear on its subway and light rail lines.
The TAP card will also be adopted by smaller transit agencies, such as Santa Monica's Big Blue Bus.