If you’re joining the ranks of workers who are 65 or older, Medicare might be the last thing on your mind. But when 65 is just around the corner, there are some important things you should know. We’ve got answers to the most common questions people ask about Medicare and working at or after 65, and what it means for your retirement plans.

Can signing up for Medicare Part B be delayed?

If you have medical coverage through an employer, or you’re covered under your spouse’s employer plan, you can delay enrolling in Medicare Part B, which covers medical services, without paying a penalty. Many people don’t enroll in Medicare Part B until they stop working.

Once you’re not covered under your employer plan (or your spouse’s), you’ll have eight months to enroll in Medicare Part B without paying a penalty.

How does enrolling in Medicare affect your HSA plan?

If you have a health plan through your employer and it includes a health savings account (HSA), signing up for Medicare Part B, or being enrolled in Medicare Part A, will change things. You can stay on your employer plan, but you can’t add money to your HSA once you enroll in Medicare.

If you’re considering this option, it’s a good idea to check with a financial adviser. They know the ins and outs of how Medicare will affect your HSA and your taxes and can help you figure out your best option.

When should you start planning for retirement?

Choosing a Medicare plan can be a long process. There’s a lot to consider and it takes time to find the right plan for you. If possible, you should start your search about six to nine months before you plan to retire.

If you don’t have that much time, you can contact plan advisers at private insurance companies that you’re interested in or meet with someone who sells plans from multiple insurance companies (called a broker or agent) one-on-one. They can help you find a plan that fits your needs and budget.

Are you required to have Medicare, and can you work full time while on Medicare?

In short, you’re not required to have Medicare and you can still work full time while on Medicare Part A. However, delaying enrollment may come with a penalty when you do enroll later than your Medicare Initial Enrollment Period (IEP). If you’re already receiving Social Security or railroad benefits, you’re automatically enrolled in Medicare Part A and Part B at 65.

How does Medicare work with employer insurance?

If you’d like to have both Medicare and employer coverage while working, the size of your company matters. If your employer has less than 20 employees, you should ask your employer’s insurance provider if you must sign up for Medicare Part A and Part B when you turn 65 as this could be a requirement. If your employer has 20 or more employees, you can generally delay signing up for Medicare until after you lose your employer-sponsored insurance.

Enrolling in at least Medicare Part A will ensure your employer benefits and Medicare benefits will work together to cover your services (the coverage through your job will pay for some services, and your Medicare plan might cover some other services). If you have an HSA through your employer’s insurance, you won’t be able to make contributions to it after signing up for Medicare.

How much does Medicare cost if you are still working?

Enrolling in Medicare Part A should come at no cost to you if you’ve worked at least 10 years and paid Medicare taxes during that time.  You can carry your employer insurance AND Medicare Part A. Enrolling in Part B might affect your employer-sponsored insurance, but delaying might also incur higher premiums and penalties, so check with your employer insurance before enrolling in Part B to learn their rules.