WASHINGTON- Medicare cards are getting a makeover to fight identity theft.

Medicare is replacing the Social Security numbers on cards with a unique new number to identify beneficiaries. The government will begin mailing new cards to participants next April, a massive transition expected to take a year.

Medicare chief Seema Verma says it's about protecting increasingly vulnerable seniors from fraud.

Medicare is revealing the cards' new design on Thursday, as the agency gears up for the change and begins telling seniors what to expect. New cards will be mailed automatically - but that's still months away so meanwhile, seniors should guard their existing card.