WASHINGTON >> Old Medicare cards will be going in the shredder.

Officials said today the government is on track to meet a 2019 deadline for replacing Social Security numbers on Medicare cards with randomly generated digits and letters to protect seniors against identity theft. Planning for the massive transition has been underway for years.

Beneficiaries and their families should start seeing changes next April, Medicare announced today. That’s when the agency will begin mailing out new cards to more than 57 million elderly and disabled beneficiaries. They’ll be instructed to destroy their old cards after they get the new one. New cards may be used right away.

Health care transitions can be notoriously tricky for the government. Remember the “Obamacare” computer system that didn’t work at first? Or the Medicare drug program rollout, when millions of low-income beneficiaries couldn’t get their prescriptions filled initially?

In a statement today, Medicare chief Seema Verma said the Trump administration is aiming for “a seamless transition” over a 21-month period that will involve coordination with beneficiaries, family members, hospitals, doctors, insurance companies, pharmacies and state governments.

Congress has set an April 2019 deadline for all beneficiaries to have new cards. Medicare has set up a website that provides some basic information.

True to government form, the new Medicare number already has an acronym: MBI, which stands for Medicare Beneficiary Identifier.

No final prototype of the new card has been unveiled, but the MBI will have 11 characters, a combination of randomly generated numbers and upper-case letters. That will easily distinguish the MBI from the familiar Medicare number, which is based on Social Security numbers.

Using Social Security numbers has been a recognized vulnerability for years, exposing seniors to identity fraud. In a digital society, having a Social Security number stolen can have immediate financial and legal consequences taking months and even years to untangle.

“Most beneficiaries will carry that Medicare card in their wallet, so if their wallet is lost or stolen, that is exactly what the identity thief is looking for,” said AARP’s Amy Nofziger, a fraud prevention expert. Private insurers have stopped using Social Security numbers on ID cards, she added, and it’s imperative that Medicare is gearing up to make the change.

Seniors are increasingly the victims of identity fraud, the government says, with a nearly 24 percent increase in such cases from 2012-2014, when 2.6 million incidents were recorded.

Nofziger warned that confusion around the transition to new Medicare cards could become an opportunity for fraudsters. Beneficiaries may get unsolicited phone calls from official-sounding people asking for personal details so new cards can be sent.

They should ignore that. Do not provide any information, said Nofziger, and instead report any such calls. “Your card will be automatically mailed to you,” she said.