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

Officials said Tuesday that the government is on track to meet a 2019 deadline for replacing Social Security numbers on all 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 Tuesday. 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 Tuesday, 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.

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.

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 or 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.