Medicare Advantage vs. Medigap: Your Summerville Guide

If you’re turning 65 in the Lowcountry or just aging into Medicare, you’re facing a decision that will shape your healthcare for the next decade or more: Medicare Advantage or Medigap. Both are real insurance. Both work with Medicare. But they are fundamentally different products, and picking the wrong one can cost you thousands of dollars or lock you out of doctors you need. Here’s what you actually need to know, from someone who sits across the table from Summerville seniors every week.

What Medicare Advantage Actually Is

Medicare Advantage (Part C) is a private insurance plan that replaces Original Medicare. You still pay your Part B premium to the government, but your coverage is managed by a private carrier. In the Summerville and greater Charleston area, the big names are Humana, UnitedHealthcare, Aetna, and BlueCross BlueShield of South Carolina.

These plans often include drug coverage (Part D), dental, vision, hearing, and sometimes gym memberships. Many have $0 monthly premiums beyond your Part B premium. That sounds great on paper.

Here’s the trade-off: you’re locked into a network. If your cardiologist at Roper St. Francis isn’t in the plan’s network, you’re paying out of pocket or switching doctors. And if you need care while traveling, your options shrink dramatically.

Medicare Advantage works best when:

• You’re relatively healthy and don’t anticipate frequent specialist visits
• You want everything bundled into one plan with one card
• Your preferred Lowcountry doctors are in the plan’s network
• You’re comfortable with copays and prior authorization requirements
• You want the $0 premium appeal

What Medigap Actually Is

Medigap (Medicare Supplement) is a private insurance policy that fills the gaps in Original Medicare. You keep Original Medicare as your primary coverage, and Medigap picks up the deductibles, copays, and coinsurance that Medicare doesn’t cover.

In South Carolina, Medigap plans are standardized by letter: Plan F (closed to new enrollees after 2020), Plan G, Plan N, and several others. Plan G is the most popular choice for new enrollees in the Summerville area because it covers nearly everything except the annual Part B deductible ($257 in 2026).

Medigap works best when:

• You see multiple specialists or have chronic conditions
• You travel frequently (Medigap works with any Medicare-accepting provider nationwide)
• You want predictable costs with minimal surprises
• You value the freedom to see any doctor who takes Medicare
• You’re willing to pay a monthly premium for that certainty

The South Carolina Carrier Lineup

For Medicare Advantage in the 29483, 29485, and 29486 zip codes, you’ll typically see 15-25 plan options during Annual Enrollment. Humana and UnitedHealthcare dominate the market here. BlueCross BlueShield of South Carolina offers strong network access across the Trident Health and Roper St. Francis systems.

For Medigap, the carriers that consistently price well in Dorchester and Berkeley counties include BlueCross BlueShield of SC, Mutual of Omaha, Aetna, and CIGNA. Plan G premiums in this area typically range from $130-$200/month depending on your age, tobacco use, and the carrier’s rating method.

One critical SC-specific detail: South Carolina uses attained-age rating for most Medigap plans. That means your premium increases as you get older. This isn’t a reason to avoid Medigap, but it’s a reason to compare carriers carefully. Some companies are more aggressive with rate increases than others.

The Real Cost Comparison

People fixate on the monthly premium, but that’s only one piece. Here’s what a realistic year looks like:

Medicare Advantage ($0 premium plan):

• Monthly premium: $0 beyond Part B
• Primary care visit: $0-$20 copay
• Specialist visit: $30-$50 copay
• Hospital stay: $250-$400/day (first 5-7 days)
• Maximum out-of-pocket: $5,000-$8,300/year
• Drug coverage: included (check formulary)

Medigap Plan G + Standalone Part D:

• Monthly Medigap premium: $130-$200
• Monthly Part D premium: $15-$75
• Part B deductible: $257/year
• After deductible: $0 for Medicare-covered services
• Maximum out-of-pocket: effectively $257/year
• Drug coverage: separate Part D plan

If you’re healthy and rarely see doctors, Medicare Advantage can save you $1,500-$3,000 a year in premiums. But one bad year (a hip replacement, a cancer diagnosis, a cardiac event at Trident Medical Center) and the out-of-pocket costs on Advantage can exceed what you’d pay all year with Medigap.

The Switching Trap Nobody Talks About

Here’s the part that catches Summerville seniors off guard: you can switch from Medigap to Medicare Advantage any year during Annual Enrollment (October 15 - December 7). No health questions asked.

But switching from Medicare Advantage back to Medigap? In South Carolina, after your initial Medigap Open Enrollment Period (the six months starting when you first enroll in Part B at age 65 or older), carriers can deny you or charge higher premiums based on your health. If you’ve developed diabetes, had a heart attack, or been diagnosed with cancer while on Medicare Advantage, you may not be able to get a Medigap plan at all.

This is the single most important thing I tell people: the Medigap door is easiest to open when you’re first eligible. Once you close it, getting back in is hard.

Which One Is Right for You?

I don’t have a default recommendation. I have a process. The Blinco Audit looks at your doctors, your prescriptions, your travel habits, your budget, and your health trajectory. Then we compare actual plans from actual carriers in your zip code.

Some of my Summerville clients are thrilled with their Medicare Advantage plans. Others switched to Medigap after one expensive year and wish they’d started there. The right answer is personal, and it starts with an honest conversation about what you need.

Frequently Asked Questions

Can I have both Medicare Advantage and Medigap at the same time?

No. Federal law prohibits carrying both. You choose one path: Medicare Advantage replaces Original Medicare, while Medigap supplements it. They serve the same purpose through different structures.

When is the best time to enroll in Medigap in South Carolina?

During your six-month Medigap Open Enrollment Period, which starts the month you turn 65 and are enrolled in Part B. During this window, no carrier in SC can deny you or charge more based on health.

Do Medicare Advantage plans cover MUSC and Roper St. Francis?

It depends entirely on the specific plan. Some plans include Trident Health, Roper, and MUSC networks. Others don’t. Always verify your doctors and hospitals are in-network before enrolling.

What happens to my Medigap plan if I move out of South Carolina?

Medigap works nationwide with any doctor who accepts Medicare. Your plan travels with you, though your premium may change based on your new state’s rating rules.

Is Plan G really the best Medigap option?

For most new enrollees, Plan G offers the strongest balance of coverage and cost. Plan N can save $30-$50/month in premiums but introduces small copays for office visits and emergency rooms.

Can my spouse and I be on different plans?

Absolutely. Each person makes their own Medicare decision. It’s common for one spouse to choose Advantage and the other Medigap, based on their individual health needs and doctor preferences.

---

I don’t stop until you’re covered. If you’re approaching 65 or already on Medicare and wondering whether you made the right choice, let’s sit down and look at the numbers together. I’m right here in Summerville.