Medicare Advantage vs. Medigap: How to Choose the Right Coverage
As a licensed Medicare agent, I help Californians make one of their biggest retirement decisions: how to fill the gaps that Original Medicare leaves behind. Two paths dominate that choice — Medicare Advantage and Medigap.
These plans work in fundamentally different ways, and you can’t have both. California also adds its own rules and protections that can shape the path serving you best.
Once you understand how each option operates, along with the 2026 costs and tradeoffs, you can pick the coverage that fits your health needs and your budget
What Is Medicare Advantage?
Medicare Advantage, also called Medicare Part C, is an all-in-one alternative plan to Original Medicare. This plan is offered by numerous private insurance companies that contract with the federal government.
When you enroll in a Medicare Advantage plan, the plan takes over administering your Part A (hospital) and Part B (medical) benefits. Most Medicare Advantage plans go further by bundling in extras not included in Original Medicare, such as prescription drug coverage (Part D) and often dental, vision, hearing, and fitness benefits.
There’s a tradeoff, though. In exchange for the bundled plan, you’ll also typically have fewer provider options due to limited providers in-network. You can’t see providers outside the network without paying extra. You’ll need referrals to see specialists, and will frequently need prior authorization for certain procedures.
Medicare Advantage Costs: Around 75% of enrollees in Medicare Advantage plans pay only $0 for plan premiums, according to KFF. In 2026, the average Medicare Advantage premium is about $15 per month.. Many plans charge no premium beyond the standard Part B premium of $202.90, which nearly everyone pays.
| Pros of Medicare Advantage | Cons of Medicare Advantage |
| Cheap premiums: Many plans cost $0 a month beyond the standard Part B premium. Around one-third of MA enrollees in these plans are in ones that reduce the Part B premium everyone pays, but often by less than $10 a month, according to KFF. Bundled extra benefits: Most plans add dental, vision, hearing, and fitness perks. Plans may also add more unusual ones such as over-the-counter discounts, acupuncture, and meal benefits. A yearly cap on your spending: In 2026, the in-network out-of-pocket limit cannot exceed $9,250, and many plans set it lower. The average is around $5,421, according to KFF. Simple, all-in-one coverage: You use one plan and one card for nearly all of your care. | Provider networks. You may be limited to certain doctors and hospitals.In California, where Advantage enrollment is high and health systems and physician groups have at times left plan networks mid-year, this can force patients to change plans or doctors. Referrals and approvals. Many plans require referrals to see specialists and prior authorization for some tests, procedures, and hospital stays. These approvals can lead to healthcare delays or denials. Yearly changes. Networks and covered benefits can change each year. A plan that fits you today may look different next January. Costs that add up. Copays for specialists, hospital stays, and other services build until you reach the out-of-pocket maximum. |
Who Is Medicare Advantage Best For?
Medicare Advantage tends to work well for people who are:
- Generally healthy, budget-conscious, and want the lowest monthly premiums
- Have good in-network hospitals and specialists nearby
- Have health conditions covered by a special-needs plan (SNP)
- Comfortable staying within a network of local providers
- Value bundled dental and vision benefits
- Don’t mind rules around referrals and authorizations
- Don’t travel extensively
If you have limited income and live in California, you may qualify for extra financial help through Medi-Cal, and be able to enroll in what’s known as a Medi-Medi plan, many of which are Medicare Advantage plans.
Dual-eligible Californians can access Medicare Savings Programs, Dual Eligible Special Needs Plans (D-SNPs), or Medicare Medi-Cal Plans that coordinate both programs. A HICAP counselor can tell you whether you qualify.
What To Consider Before You Buy a Medicare Advantage Plan
Before enrolling, confirm that your preferred doctors and hospitals are in the plan’s network — and verify directly with the providers or your agent, since online directories aren’t always accurate.
Check that your prescriptions are on the plan’s formulary (list of medications) and see what tier they fall into to estimate your costs.
Don’t get too invested in a $0 premium. Some lower-premium plans may cost more by the year’s end by the time you include the plan’s out-of-pocket maximum and the specific copays for primary care, specialists, and emergency or hospital care.
If you have a PPO and might use out-of-network providers, note that the combined in- and out-of-network out-of-pocket maximums can be much higher, around $13,900 in 2026.
Also review the “Annual Notice of Change” (ANOC) letter you receive every year, because benefits, networks, costs, and drug coverage can shift from one year to the next.
What Is Medigap?
Medigap, also known as Medicare Supplement insurance, works alongside Original Medicare as an additional layer. Original Medicare acts as your primary coverage for costs (80%), and your Medigap policy automatically pays its portion of the remaining amount, based on your plan letter. You typically don’t have to file claims or get pre-approval..
The best time to buy a plan is your six-month Medigap Open Enrollment Period, which starts when you are 65 and enrolled in Part B. Insurers cannot deny you or charge you more for health reasons during that window.
Medigap plans are standardized and labeled by letter (A, B, C, D, F, G, K, L, M, and N). Because they’re standardized, a Plan G from one insurer covers the same benefits as a Plan G from another. Only the price and the company differ. Plans are guaranteed renewable, so your coverage stays the same year to year as long as you pay the premium.
Plan G and Plan N are the most popular choices for new enrollees today. Plans C and F, which cover the Part B deductible, are no longer available to people who became eligible for Medicare on or after January 1, 2020, though longtime enrollees may keep them.
Medigap Costs: You pay the Medigap premium on top of your Part B premium,and California prices vary widely by region. Plan G premiums tend to run higher in coastal metros like Los Angeles, the Bay Area, and San Diego, and lower in inland and rural counties.
California insurers also price policies in different ways, which affects how your premium changes as you get older or if you move within California.
Medigap does not include prescription drug coverage or any other type of coverage, such as dental coverage. Most people who choose this route also buy a separate standalone Part D plan.
What Are the Pros and Cons of Medigap?
| Pros of Medigap | Cons of Medigap Plans |
| Wide access to providers. You can see almost any doctor or hospital in the country that accepts Medicare. Few restrictions. There are no networks and no referrals, and prior authorization is rare. Coverage that travels. Your benefits work anywhere in the U.S. This helps people who snowbird or travel often. Predictable costs. A plan like Plan G covers the Part A hospital deductible the 20% Part B coinsurance, and most other gaps. After you pay your premium and the Part B deductible ($283 in 2026), you have very little added cost for covered care. | Higher premiums. In 2026, Plan G often costs $130 to $250 per month, depending on your age, location, gender, and insurer. Premiums are rising: Due to inflation and more use, Medigap plan costs are rising every year. No drug coverage or extras. You typically arrange and pay for drug, dental, and other coverages on your own or with the help of an agent. Tricky timing. After the initial enrollment window, most states allow medical underwriting. You could be turned down or charged more based on your health for a Medigap plan if you buy one during that window. |
Who Is Medigap Best For?
Medigap is often the better fit for people who:
- Want maximum provider flexibility and the ability to see any Medicare provider without network worries, such as people who often see specialists outside an established network.
- Want predictable costs and are willing to pay a higher premium to get that predictability, versus copays or other extra costs.
- Can sign up in the initial Medigap Open Enrollment Period to lock in coverage and the best rates.
- Have ongoing health conditions
- Don’t mind shopping for Part D plans
- Travel frequently or spend time out of their home state
Medigap offers a uniquely good deal for California residents that many other states don’t offer. Each year, you get a 60-day window that starts on your birthday to switch to another Medigap plan with equal or lesser benefits — from any carrier — without answering health questions.
In addition, nearly a half-million Californians qualify for Medicare before age 65 through a disability. Unlike federal law, California law guarantees these beneficiaries access to Medigap. Insurers in the state must offer at least Plans A, B, D, and G to eligible under-65 enrollees.
What To Consider Before You Buy a Medicare Supplement
Start by choosing a plan letter that matches the level of cost-sharing you’re comfortable with. Then, because benefits are identical across insurers for a given letter, shop the price aggressively — the same plan can vary by hundreds of dollars a year between companies.
Plan G offers the most comprehensive coverage available to new enrollees, and the high-deductible Plan G offers a low premium but you’ll need to be prepared to pay a hefty deductible before coverage kicks in at all. Plan N trades a slightly lower premium for small copays on some office and emergency room visits.
Ask how the insurer prices its policies (community-rated, issue-age, or attained-age), since that affects how your premium rises over time.
Confirm you’re enrolling during your Open Enrollment Period to avoid underwriting, and remember to add a standalone Part D drug plan so you’re covered at the pharmacy.
How Does Medigap Work with Medicare and Medicare Advantage?
This is where a lot of confusion arises. Medigap is designed to supplement Original Medicare only and it does not work with Medicare Advantage.
In fact, it’s illegal for an insurer or agent to sell you a Medigap policy if you have Medicare Advantage. You can only use Medigap with Original Medicare. If you’re currently in Medicare Advantage and want to switch to Original Medicare with a Medigap policy, you may need to pass medical underwriting to get the Medigap plan.
That’s why the decision between these two paths is often easiest to make cleanly when you first enroll in Medicare.
California residents benefit from extra protections, though. When a qualifying event gives you a guaranteed-issue right — your Advantage plan leaves the market, you move out of its service area, or the plan drops your doctors — you can buy a Medigap policy with no health screening.
The federal window for this is 63 days. California adds a 60-day open enrollment period on top of it, for a total of 123 days.
Frequently Asked Questions
What is the downside of Medigap?
The main downside is cost. Medigap monthly premiums are much higher than most Medicare Advantage premiums — often $130 or more per month for a plan like Plan G — and that’s on top of your Part B premium and a separate Part D drug plan. Medigap also doesn’t include prescription drugs, dental, vision, or hearing benefits, and if you buy outside your open enrollment window, you may face medical underwriting.
How much does Medigap cost per month?
It varies widely by plan, age, location, and insurer, but most people pay somewhere between about $50 and $350 a month. In 2026, Plan G frequently runs around $130 to $250 monthly, Plan N tends to be a bit lower, and high-deductible Plan G can be as little as $40 to $70. Because benefits are standardized, comparing quotes from several insurers for the same plan letter can save you a meaningful amount.
What is the biggest disadvantage of a Medicare Advantage plan?
The most significant disadvantage is the restriction on where you can get care. Medicare Advantage plans rely on provider networks and often require referrals and prior authorization, so your choice of doctors and hospitals is limited. Out-of-network care can be expensive or uncovered. Networks and benefits can also change each year, and costs can add up as you work toward the plan’s out-of-pocket maximum.
Do doctors prefer Medicare Supplement or Medicare Advantage?
Many doctors find Original Medicare paired with a Medigap plan easier to work with, because it involves fewer network restrictions, less prior authorization, and more straightforward reimbursement. Medicare Advantage plans can require more administrative steps and approvals. That said, preferences vary by practice, and what matters most for you is confirming that your specific providers accept whichever coverage you choose.
This article is for general educational purposes and reflects 2026 figures. Costs and plan rules change annually and vary by location, so confirm current details with Medicare.gov, a licensed insurance agent, or your State Health Insurance Assistance Program (SHIP) before making a decision.As a licensed Medicare agent, I help Californians make one of their biggest retirement decisions: how to fill the gaps that Original Medicare leaves behind. Two paths dominate that choice — Medicare Advantage and Medigap.
These plans work in fundamentally different ways, and you can’t have both. California also adds its own rules and protections that can shape the path serving you best.
Once you understand how each option operates, along with the 2026 costs and tradeoffs, you can pick the coverage that fits your health needs and your budget
What Is Medicare Advantage?
Medicare Advantage, also called Medicare Part C, is an all-in-one alternative plan to Original Medicare. This plan is offered by numerous private insurance companies that contract with the federal government.
When you enroll in a Medicare Advantage plan, the plan takes over administering your Part A (hospital) and Part B (medical) benefits. Most Medicare Advantage plans go further by bundling in extras not included in Original Medicare, such as prescription drug coverage (Part D) and often dental, vision, hearing, and fitness benefits.
There’s a tradeoff, though. In exchange for the bundled plan, you’ll also typically have fewer provider options due to limited providers in-network. You can’t see providers outside the network without paying extra. You’ll need referrals to see specialists, and will frequently need prior authorization for certain procedures.
Medicare Advantage Costs: Around 75% of enrollees in Medicare Advantage plans pay only $0 for plan premiums, according to KFF. In 2026, the average Medicare Advantage premium is about $15 per month.. Many plans charge no premium beyond the standard Part B premium of $202.90, which nearly everyone pays.
| Pros of Medicare Advantage | Cons of Medicare Advantage |
| Cheap premiums: Many plans cost $0 a month beyond the standard Part B premium. Around one-third of MA enrollees in these plans are in ones that reduce the Part B premium everyone pays, but often by less than $10 a month, according to KFF. Bundled extra benefits: Most plans add dental, vision, hearing, and fitness perks. Plans may also add more unusual ones such as over-the-counter discounts, acupuncture, and meal benefits. A yearly cap on your spending: In 2026, the in-network out-of-pocket limit cannot exceed $9,250, and many plans set it lower. The average is around $5,421, according to KFF. Simple, all-in-one coverage: You use one plan and one card for nearly all of your care. | Provider networks. You may be limited to certain doctors and hospitals.In California, where Advantage enrollment is high and health systems and physician groups have at times left plan networks mid-year, this can force patients to change plans or doctors. Referrals and approvals. Many plans require referrals to see specialists and prior authorization for some tests, procedures, and hospital stays. These approvals can lead to healthcare delays or denials. Yearly changes. Networks and covered benefits can change each year. A plan that fits you today may look different next January. Costs that add up. Copays for specialists, hospital stays, and other services build until you reach the out-of-pocket maximum. |
Who Is Medicare Advantage Best For?
Medicare Advantage tends to work well for people who are:
- Generally healthy, budget-conscious, and want the lowest monthly premiums
- Have good in-network hospitals and specialists nearby
- Have health conditions covered by a special-needs plan (SNP)
- Comfortable staying within a network of local providers
- Value bundled dental and vision benefits
- Don’t mind rules around referrals and authorizations
- Don’t travel extensively
If you have limited income and live in California, you may qualify for extra financial help through Medi-Cal, and be able to enroll in what’s known as a Medi-Medi plan, many of which are Medicare Advantage plans.
Dual-eligible Californians can access Medicare Savings Programs, Dual Eligible Special Needs Plans (D-SNPs), or Medicare Medi-Cal Plans that coordinate both programs. A HICAP counselor can tell you whether you qualify.
What To Consider Before You Buy a Medicare Advantage Plan
Before enrolling, confirm that your preferred doctors and hospitals are in the plan’s network — and verify directly with the providers or your agent, since online directories aren’t always accurate.
Check that your prescriptions are on the plan’s formulary (list of medications) and see what tier they fall into to estimate your costs.
Don’t get too invested in a $0 premium. Some lower-premium plans may cost more by the year’s end by the time you include the plan’s out-of-pocket maximum and the specific copays for primary care, specialists, and emergency or hospital care.
If you have a PPO and might use out-of-network providers, note that the combined in- and out-of-network out-of-pocket maximums can be much higher, around $13,900 in 2026.
Also review the “Annual Notice of Change” (ANOC) letter you receive every year, because benefits, networks, costs, and drug coverage can shift from one year to the next.
What Is Medigap?
Medigap, also known as Medicare Supplement insurance, works alongside Original Medicare as an additional layer. Original Medicare acts as your primary coverage for costs (80%), and your Medigap policy automatically pays its portion of the remaining amount, based on your plan letter. You typically don’t have to file claims or get pre-approval..
The best time to buy a plan is your six-month Medigap Open Enrollment Period, which starts when you are 65 and enrolled in Part B. Insurers cannot deny you or charge you more for health reasons during that window.
Medigap plans are standardized and labeled by letter (A, B, C, D, F, G, K, L, M, and N). Because they’re standardized, a Plan G from one insurer covers the same benefits as a Plan G from another. Only the price and the company differ. Plans are guaranteed renewable, so your coverage stays the same year to year as long as you pay the premium.
Plan G and Plan N are the most popular choices for new enrollees today. Plans C and F, which cover the Part B deductible, are no longer available to people who became eligible for Medicare on or after January 1, 2020, though longtime enrollees may keep them.
Medigap Costs: You pay the Medigap premium on top of your Part B premium,and California prices vary widely by region. Plan G premiums tend to run higher in coastal metros like Los Angeles, the Bay Area, and San Diego, and lower in inland and rural counties.
California insurers also price policies in different ways, which affects how your premium changes as you get older or if you move within California.
Medigap does not include prescription drug coverage or any other type of coverage, such as dental coverage. Most people who choose this route also buy a separate standalone Part D plan.
What Are the Pros and Cons of Medigap?
| Pros of Medigap | Cons of Medigap Plans |
| Wide access to providers. You can see almost any doctor or hospital in the country that accepts Medicare. Few restrictions. There are no networks and no referrals, and prior authorization is rare. Coverage that travels. Your benefits work anywhere in the U.S. This helps people who snowbird or travel often. Predictable costs. A plan like Plan G covers the Part A hospital deductible the 20% Part B coinsurance, and most other gaps. After you pay your premium and the Part B deductible ($283 in 2026), you have very little added cost for covered care. | Higher premiums. In 2026, Plan G often costs $130 to $250 per month, depending on your age, location, gender, and insurer. Premiums are rising: Due to inflation and more use, Medigap plan costs are rising every year. No drug coverage or extras. You typically arrange and pay for drug, dental, and other coverages on your own or with the help of an agent. Tricky timing. After the initial enrollment window, most states allow medical underwriting. You could be turned down or charged more based on your health for a Medigap plan if you buy one during that window. |
Who Is Medigap Best For?
Medigap is often the better fit for people who:
- Want maximum provider flexibility and the ability to see any Medicare provider without network worries, such as people who often see specialists outside an established network.
- Want predictable costs and are willing to pay a higher premium to get that predictability, versus copays or other extra costs.
- Can sign up in the initial Medigap Open Enrollment Period to lock in coverage and the best rates.
- Have ongoing health conditions
- Don’t mind shopping for Part D plans
- Travel frequently or spend time out of their home state
Medigap offers a uniquely good deal for California residents that many other states don’t offer. Each year, you get a 60-day window that starts on your birthday to switch to another Medigap plan with equal or lesser benefits — from any carrier — without answering health questions.
In addition, nearly a half-million Californians qualify for Medicare before age 65 through a disability. Unlike federal law, California law guarantees these beneficiaries access to Medigap. Insurers in the state must offer at least Plans A, B, D, and G to eligible under-65 enrollees.
What To Consider Before You Buy a Medicare Supplement
Start by choosing a plan letter that matches the level of cost-sharing you’re comfortable with. Then, because benefits are identical across insurers for a given letter, shop the price aggressively — the same plan can vary by hundreds of dollars a year between companies.
Plan G offers the most comprehensive coverage available to new enrollees, and the high-deductible Plan G offers a low premium but you’ll need to be prepared to pay a hefty deductible before coverage kicks in at all. Plan N trades a slightly lower premium for small copays on some office and emergency room visits.
Ask how the insurer prices its policies (community-rated, issue-age, or attained-age), since that affects how your premium rises over time.
Confirm you’re enrolling during your Open Enrollment Period to avoid underwriting, and remember to add a standalone Part D drug plan so you’re covered at the pharmacy.
How Does Medigap Work with Medicare and Medicare Advantage?
This is where a lot of confusion arises. Medigap is designed to supplement Original Medicare only and it does not work with Medicare Advantage.
In fact, it’s illegal for an insurer or agent to sell you a Medigap policy if you have Medicare Advantage. You can only use Medigap with Original Medicare. If you’re currently in Medicare Advantage and want to switch to Original Medicare with a Medigap policy, you may need to pass medical underwriting to get the Medigap plan.
That’s why the decision between these two paths is often easiest to make cleanly when you first enroll in Medicare.
California residents benefit from extra protections, though. When a qualifying event gives you a guaranteed-issue right — your Advantage plan leaves the market, you move out of its service area, or the plan drops your doctors — you can buy a Medigap policy with no health screening.
The federal window for this is 63 days. California adds a 60-day open enrollment period on top of it, for a total of 123 days.
Frequently Asked Questions
What is the downside of Medigap?
The main downside is cost. Medigap monthly premiums are much higher than most Medicare Advantage premiums — often $130 or more per month for a plan like Plan G — and that’s on top of your Part B premium and a separate Part D drug plan. Medigap also doesn’t include prescription drugs, dental, vision, or hearing benefits, and if you buy outside your open enrollment window, you may face medical underwriting.
How much does Medigap cost per month?
It varies widely by plan, age, location, and insurer, but most people pay somewhere between about $50 and $350 a month. In 2026, Plan G frequently runs around $130 to $250 monthly, Plan N tends to be a bit lower, and high-deductible Plan G can be as little as $40 to $70. Because benefits are standardized, comparing quotes from several insurers for the same plan letter can save you a meaningful amount.
What is the biggest disadvantage of a Medicare Advantage plan?
The most significant disadvantage is the restriction on where you can get care. Medicare Advantage plans rely on provider networks and often require referrals and prior authorization, so your choice of doctors and hospitals is limited. Out-of-network care can be expensive or uncovered. Networks and benefits can also change each year, and costs can add up as you work toward the plan’s out-of-pocket maximum.
Do doctors prefer Medicare Supplement or Medicare Advantage?
Many doctors find Original Medicare paired with a Medigap plan easier to work with, because it involves fewer network restrictions, less prior authorization, and more straightforward reimbursement. Medicare Advantage plans can require more administrative steps and approvals. That said, preferences vary by practice, and what matters most for you is confirming that your specific providers accept whichever coverage you choose.
This article is for general educational purposes and reflects 2026 figures. Costs and plan rules change annually and vary by location, so confirm current details with Medicare.gov, a licensed insurance agent, or your State Health Insurance Assistance Program (SHIP) before making a decision.