Medicare is a valuable benefit, but it’s also one of the most complicated programs many retirees will ever deal with. Between enrollment deadlines, coordination rules, and confusing billing procedures, even well-meaning beneficiaries can make mistakes that lead to penalties or unexpected expenses.
At Carolina Senior Benefits, we’ve guided thousands of people through Medicare enrollment and seen the same costly missteps repeated over and over. Let’s walk through the five most common Medicare mistakes and what you can do to avoid them.
1. Waiting Too Long to Enroll in Medicare
Timing is everything when it comes to Medicare. Your Initial Enrollment Period (IEP) begins three months before the month you turn 65 and ends three months after. That’s your first (and most important) chance to enroll in Medicare Parts A and B.
Here’s what many people don’t realize: your start date depends on when you enroll. If you wait until your birthday month or the three months after, your Part B coverage might not start immediately, leaving a gap in your insurance.
Even worse, if you miss your IEP and don’t have other qualifying coverage, you’ll need to wait until the General Enrollment Period (January 1–March 31) to sign up and you could owe a 10% penalty for every year you delayed Part B.
Enroll early in your IEP to ensure your coverage starts on time and to avoid any costly late penalties.
2. Relying on COBRA Instead of Enrolling in Medicare
COBRA coverage often feels like an easy bridge between employer insurance and retirement, but it’s one of Medicare’s most confusing traps.
While COBRA lets you stay on your employer’s health plan for a limited time after leaving your job, it’s not considered creditable coverage for Medicare Part B. That means if you stay on COBRA and delay enrolling in Medicare, you’ll face late enrollment penalties and potential coverage gaps once COBRA ends.
Even worse, many COBRA plans will drop you as soon as you become eligible for Medicare, leaving you without any coverage at all.
Don’t rely on COBRA alone. If you’re eligible for Medicare, enroll in Parts A and B right away. COBRA can serve as secondary coverage, but it should never replace Medicare as your main insurance.
3. Assuming Your Employer Plan Is Always Primary
Still working after 65? Whether Medicare or your employer coverage pays first depends on your company’s size.
If your employer has 20 or fewer employees, Medicare becomes your primary coverage and your employer plan pays second. Many people don’t know this, so they skip enrolling in Medicare only to find that their claims aren’t covered because Medicare should have been billed first. If you work for a small business and delay Medicare, you could end up paying out of pocket for services your employer plan refuses to cover.
If your company has more than 20 employees, your employer coverage remains primary and Medicare is secondary.
Before making any enrollment decisions, check with your HR department to confirm how your plan coordinates with Medicare.
4. Not Understanding How the Part B Deductible Works
Medicare billing can be confusing, and even doctor’s offices sometimes get it wrong.
Part B of Medicare includes a small annual deductible ($240 in 2024). You’re responsible for paying this amount before Medicare starts paying its share. After you’ve met the deductible, Medicare covers 80% of approved costs, and you pay the remaining 20% unless you have a Medigap plan to cover those gaps.
Some beneficiaries are billed incorrectly or pay too early because their provider doesn’t understand when the deductible applies.
To avoid confusion:
- Remember, the Part B deductible applies once per year, not per visit.
- It only applies to outpatient and doctor services, not hospital stays.
- Medigap Plans C and F cover this deductible, but newer enrollees must choose from other plans.
Knowing these rules can save you from unnecessary bills and frustration at the doctor’s office.
5. Mixing Up the Annual Election Period and Medigap Open Enrollment
This one confuses nearly everyone. The Annual Election Period (AEP) (which runs from October 15 to December 7) is for switching or enrolling in Medicare Advantage and Part D prescription plans, not Medigap.
Your one-time Medigap Open Enrollment Period begins when you first enroll in Part B and lasts six months. During that window, you can sign up for any Medigap plan available in your state with no health questions or underwriting.
After that, insurance companies can require medical underwriting and may deny coverage or charge more if you have preexisting conditions.
If you’re thinking about buying a Medigap plan, don’t wait until fall’s AEP. Take advantage of your six-month Medigap window when you first start Medicare Part B. You might not get another guaranteed chance.
Take the Guesswork Out of Medicare
Each of these mistakes can cause headaches, penalties, or gaps in coverage, but they’re all preventable with the right information.
At Carolina Senior Benefits, we help you understand your options, compare plans, and enroll correctly the first time. Whether you’re new to Medicare or just want a second opinion on your current coverage, our licensed agents can help you make smart, confident decisions about your healthcare.
