Should You Sign Up for Social Security and Medicare at the Same Time? 3 Things You Should Know

If you're approaching Medicare eligibility age at 65 and you haven't yet applied for Social Security, it's natural to wonder whether you should apply for both at the same time. It might mean a little more time spent filling out paperwork initially, but then you'll start getting help with your healthcare costs and your other monthly expenses.

There's nothing to stop you from doing this if that's what you want. But there are a few little-known rules to bear in mind before you make any decisions.

1. You'll face an early Social Security claiming penalty for applying at 65

If you apply for Social Security when you become eligible for Medicare at 65, you'll technically be considered an early claimer. For most workers today, full retirement age (FRA) is 67. Claiming before this age reduces your checks by 5/9 of 1% per month (6.67% per year) for up to 36 months of early claiming.

Claiming at 65 would shrink your checks by more than 13%, and that reduction is usually permanent. That's enough to knock the $2,084 average monthly benefit as of June 2026 down to roughly $1,813 per month. It could also reduce your lifetime benefit. Make sure you're comfortable with this trade-off before you decide to apply for Social Security when you apply for Medicare.

2. If you sign up for Medicare first, you'll have to pay your Part B premiums out of pocket

Social Security beneficiaries who enroll in Medicare have their Part B premiums automatically withheld from their checks. This gives them one less bill to track. Seniors who apply for Medicare first don't have this option. They'll have to pay for their Part B premiums on their own.

This usually isn't a big deal if you set up automatic bill pay through your bank account. Once you apply for Social Security, your premiums will begin to come out of your benefit checks unless you elect otherwise.

3. Applying for Medicare late carries steep penalties

If you decide to delay your Social Security application to avoid the early claiming penalty, don't delay your Medicare application, too. Failing to enroll during your Initial Enrollment Period, which runs from three months before you turn 65 to three months after you turn 65, permanently increases your Part B premiums by 10% for every year you could have signed up but didn't.

You could also face a Part D late enrollment penalty of 1% per month for every month you don't join a Medicare drug plan after becoming eligible. Like the Part B penalty, this is a permanent rate increase, not a one-time fee.

If you have any questions about your Social Security or Medicare benefits, contact the respective organizations for more information. A call today could save you from making a costly mistake down the road.

The Motley Fool has a disclosure policy.