Medicare Advantage vs Medigap in San Diego County: 2026 Comparison
Turning 65 in San Diego forces a decision most people have never studied. You can stay with Original Medicare and add a Medigap policy, or you can move into a private Medicare Advantage plan. If you’ve typed “Medicare Advantage San Diego” into a search bar and come away with a pile of $0-premium ads, you’re not alone.
The choice affects which doctors you can see, what a bad health year costs, and whether you can change your mind later. This guide compares the two paths using 2026 federal figures, San Diego County plan data and California’s own Medigap rules. It then walks through two worked examples for local households.
All figures come from publicly available sources as of September 21, 2026. Premiums, plan lineups and rules can change, especially with 2027 plans arriving this fall.
Quick Answer: Medicare Advantage plans in San Diego County usually have a $0 or low premium. They also have an annual out-of-pocket cap, which can be no higher than $9,250 in-network in 2026, and often include extras like dental. In exchange, you’re tied to a network and to prior authorization rules. Medigap works alongside Original Medicare and lets you see any provider nationwide that accepts Medicare. With Plan G, you pay little beyond the $283 Part B deductible. However, MoneyGeek’s 2026 California data shows Plan G and Plan N premiums of roughly $127 to $307 a month at age 65, and you need a separate drug plan on top. Which path fits depends on your doctors, your health, your travel habits and your budget. A free HICAP counselor or a licensed agent can help you weigh your own situation.
How the Two Paths Work (and Why You Can’t Have Both)
Medicare gives you two main routes. It helps to picture them as two different houses rather than two rooms in the same house. You live in one or the other.
Path 1: Original Medicare + Medigap + Part D
Original Medicare (Part A for hospital care and Part B for medical care) is run by the federal government. It pays most of the bill but leaves gaps: deductibles, a 20% coinsurance on most outpatient care, and no annual cap on what you can owe.
A Medigap policy, also called Medicare Supplement Insurance, is sold by private insurers and fills those gaps. According to Medicare.gov, Medigap plans sold after 2005 don’t include drug coverage. Most people on this path therefore add a standalone Part D drug plan.
Medicare.gov also notes several features of Medigap policies:
- Each policy covers one person, so spouses buy separately.
- Standardized policies renew automatically every year, even if your health changes.
- The insurer can only drop you for three reasons: you stop paying, you weren’t truthful on the application, or the company goes out of business.
Path 2: Medicare Advantage (Part C)
A Medicare Advantage plan is a private HMO or PPO that replaces Original Medicare as the way you get your benefits. Most San Diego plans bundle hospital, medical and drug coverage. Many add dental, vision and hearing benefits.
Medicare pays the insurer a set monthly amount for you. The insurer then manages your care through a provider network and rules like referrals and prior authorization.
The key rule from Medicare.gov is that you can have one or the other, not both. You can’t buy Medigap while enrolled in Medicare Advantage unless you’re switching back to Original Medicare. Medigap also can’t pay a Medicare Advantage plan’s copays or premiums.
The 2026 Numbers Every San Diego Shopper Needs
Some costs apply no matter which path you choose. Others only matter on one side.
Federal costs that apply to almost everyone
The Centers for Medicare & Medicaid Services (CMS) set the 2026 standard Part B premium at $202.90 a month, up from $185 in 2025. The Part B deductible is $283.
CMS also reports that about 99% of beneficiaries pay no Part A premium. That’s because they have at least 40 quarters of Medicare-covered work history.
If you choose Original Medicare without a Medigap policy, the Part A hospital deductible is $1,736 per benefit period in 2026. A benefit period isn’t the same as a calendar year, so this deductible can apply more than once in a year. Hospital days 61 through 90 cost $434 a day. Skilled nursing days 21 through 100 cost $217 a day.
| 2026 figure | Amount | What it means for you |
|---|---|---|
| Part B standard premium | $202.90/month | Paid on both paths |
| Part B deductible | $283/year | Plan G leaves you paying this |
| Part A hospital deductible | $1,736 per benefit period | Covered by most Medigap plans; Medicare Advantage uses its own copays |
| Medicare Advantage out-of-pocket cap | $9,250 in-network; $13,900 combined | The legal maximum; many plans set lower caps |
| Part D drug out-of-pocket cap | $2,100 | Applies to standalone drug plans and Medicare Advantage drug coverage |
| High-deductible Plan G deductible | $2,950 | You pay this much before the policy pays |
| Plan K / Plan L out-of-pocket limits | $8,000 / $4,000 | The only Medigap plans with yearly caps |
Sources: CMS, KFF, Medicare.gov (2026).
Higher earners pay more on both paths
CMS adds income-related surcharges (called IRMAA) to Part B and Part D premiums. These apply once modified adjusted gross income passes $109,000 for single filers or $218,000 for joint filers. At the top bracket, the total Part B premium reaches $689.90 a month.
Plenty of retirees in coastal ZIP codes with pensions, rental income or large IRA withdrawals cross these lines. IRMAA hits both paths equally, so it doesn’t favor one over the other. It does raise the total cost of your Medicare either way.
The Medicare Advantage San Diego Market in 2026
San Diego County is a crowded Medicare Advantage market. It is also a market shaped by a few big local health systems.
How many plans are there? It depends who’s counting
Plan counts vary widely from one website to the next.
- Medicare.org (a site owned by Allstate) counts 60 Medicare Advantage options in the county for 2026. It excludes special needs plans, and 51 of the 60 charge no premium beyond Part B.
- MedicareAdvantage.com lists 37. Its table only shows plans from the carriers it represents, and it mixes in some special needs plans. That’s why names like SCAN, Sharp Direct Advantage, Blue Shield and Alignment Health don’t appear on it.
The averages differ for the same reasons:
| Measure | Medicare.org | MedicareAdvantage.com | KFF (national) |
|---|---|---|---|
| Average monthly premium | $6.92 | $4.04 | Not comparable (see note) |
| Average in-network out-of-pocket cap | $3,312 | $4,034 | $5,421 |
| Average star rating | 3.64 | 3.19 | n/a |
The two county averages are calculated across different sets of plans. KFF’s national $5,421 figure is enrollment-weighted, which means big plans count more than small ones. KFF’s premium measure is also different: it is the average extra premium paid by enrollees in Medicare Advantage plans that include drug coverage.
None of these figures is wrong. They just measure different things. For your own shopping, the Medicare Plan Finder at Medicare.gov is the only tool that shows every plan in your ZIP code.
Who dominates locally
Medicare.org’s September 2026 enrollment data shows three plans with the most members in San Diego:
- Kaiser Permanente Senior Advantage San Diego (HMO): about 67,940 members
- UHC Sharp Medicare Advantage ValueRx (HMO-POS): about 20,800 members
- SCAN Alta (HMO): about 17,985 members
About 219,962 people countywide are enrolled in individual (non-special-needs) plans. HMOs dominate. Medicare.org counts 40 HMO plans with an average cap of $2,815, compared with eight PPOs averaging $6,269.
Local plan designs vary a lot. Kaiser’s main Senior Advantage plan lists a $0 premium and a $1,800 in-network cap, and MedicareAdvantage.com shows it at 4.5 stars. Some plans elsewhere on the county list sit at the $9,250 federal maximum.
Networks can change mid-year
This is the part of Medicare Advantage that rarely makes the brochure. UC San Diego Health’s own website says SCAN dropped UC San Diego Health primary care physicians from its Medicare HMO network. The change took effect March 1, 2026, and only UCSD Health Network Affiliates remain in-network.
The same page shows how limited academic-center access can be. UC San Diego Health lists only certain HMOs for specialty care. It is out of network for the Aetna and Humana PPOs. On the other hand, it states that it accepts all Medigap plans.
The lesson isn’t about any one health system. With Medicare Advantage, your doctor list is only as stable as the contract between the plan and the medical group.
Prior authorization and extras
KFF found that 99% of Medicare Advantage enrollees nationally are in plans requiring prior authorization for some services. It is most common for hospital stays, skilled nursing and Part B drugs. KFF also reports that in 2024, insurers received nearly 53 million prior authorization requests and denied about 8% of them.
On the upside, KFF says nearly all individual-plan enrollees have some dental, vision and hearing coverage. The depth of those benefits varies widely from plan to plan.
KFF also found that about a third of enrollees are in plans that reduce the Part B premium, often marketed as a “giveback.” Among those enrollees, 39% get less than $10 a month back.
Medigap in California: What It Costs and How It’s Priced
Medigap benefits are standardized by federal law. A Plan G from one insurer covers exactly what a Plan G from another insurer covers. What differs is the premium, and how that premium changes as you age.
What Plan G, Plan N and Plan K cost at 65
MoneyGeek’s 2026 California analysis priced policies for 65-year-olds. Its results:
- Plan G: from $166 a month (State Farm) to $307 (Aetna). State Farm’s price is $58 below MoneyGeek’s statewide average, which implies an average of about $224.
- Plan N: from $127 to $230 a month.
- Plan K: as low as $78 a month (AARP).
MoneyGeek doesn’t break these figures out by ZIP code, gender or tobacco use. Premiums in San Diego ZIPs can differ from the statewide numbers.
The California Department of Insurance (CDI) publishes an official 2026 Medicare Supplement rate guide. It shows approved annual rates for non-tobacco users by plan letter, age and ZIP code, including high-deductible Plans F and G. It is the most reliable way to see San Diego-specific prices.
Why the starting price isn’t the whole story
Insurers use three pricing methods. MoneyGeek explains them like this:
- Attained-age pricing (used by State Farm and many others) starts cheaper, then rises every year as you age.
- Issue-age pricing (Transamerica, in MoneyGeek’s sample) sets your rate based on the age when you bought the policy.
- Community pricing (AARP) charges everyone the same rate regardless of age.
Over a decade or more, a policy with a cheap attained-age starting price can end up costing more in total than a community-rated one. All three types can still raise rates for inflation and claims.
Which plans most new enrollees consider
Plan G. Plans C and F aren’t available to people who became eligible for Medicare on or after January 1, 2020. That leaves Plan G as the most complete option for new enrollees. Per Medicare.gov, it covers everything except the Part B deductible, including Part B excess charges and foreign travel emergencies.
Plan N. It trades a lower premium for up to $20 copays at some office visits and up to $50 for ER visits that don’t lead to admission. It also doesn’t cover excess charges, which are extra fees some doctors can bill above Medicare’s approved amount.
High-deductible Plan G. It suits people who want catastrophic protection at a low premium and can absorb the first $2,950 in a bad year.
Medicare Advantage vs Medigap: Side-by-Side Comparison
| Feature | Medicare Advantage (typical San Diego plan) | Original Medicare + Medigap Plan G + Part D |
|---|---|---|
| Monthly premium beyond Part B | Often $0; county averages of about $4–$7 | About $166–$307 for Plan G at 65, plus a Part D premium (KFF national average $36) |
| Annual out-of-pocket cap (medical) | Up to $9,250 in-network; many local HMOs $500–$3,400 | No formal cap, but you pay only the $283 Part B deductible for Medicare-covered care |
| Doctor choice | Plan network; HMOs usually need referrals | Any U.S. provider that accepts Medicare |
| Prior authorization | Common for hospital, skilled nursing, Part B drugs | Rarely used in Original Medicare |
| Drug coverage | Usually built in | Separate Part D plan |
| Dental, vision, hearing | Often included, with limits | Not included; buy separately |
| Travel within the U.S. | Emergencies covered; routine care limited by network | Same coverage nationwide |
| Emergencies abroad | Varies by plan | Plan G pays 80% after $250, up to a $50,000 lifetime limit |
| Annual changes | Benefits and networks can change each January | Benefits are standardized; premiums change |
| Switching later | Easy during enrollment windows | Returning to Medigap may require health questions (see next section) |
Two points in that table surprise people.
A low Medicare Advantage cap can beat Medigap in a bad year. A plan with a $1,800 cap can cost less in total than Plan G, even when you’re sick. The trade-off is network freedom, not always dollars.
Drug costs are capped on both paths. The $2,100 Part D limit means drug costs alone no longer tip the scales as heavily toward either side.
California’s Birthday Rule and Other Switching Rights
This is where California really differs from most states. It is also where timing mistakes can be permanent.
Your one-time Medigap window at 65
California Insurance Code Section 10192.11 bars insurers from denying you or charging more because of your health during a specific window. You must apply before or during the six months that start the first month you’re both 65 and enrolled in Part B.
After that window, insurers can generally ask health questions and turn you down, unless another protection applies.
California goes further than federal law in two ways:
- Under-65 access. The state code requires insurers to offer certain plans to Medicare beneficiaries under 65 who don’t have end-stage renal disease. For people newly eligible since 2020, those plans are A, B, D and G, plus K or L and M or N.
- Local protections. The code gives guaranteed-issue rights to military retirees who lose care because a base closes. It also adds an extra 60 days of Medigap open enrollment after a Medicare Advantage plan ends its coverage.
The birthday rule and the confusion around it
The current statute gives Medigap policyholders an annual open enrollment period. It lasts at least 60 days and starts on their birthday. During that time, you can buy any Medigap policy with equal or lesser benefits, from any insurer, without health underwriting. The key requirement is that you must already have a Medigap policy.
Published sources describe this window differently:
- MoneyGeek says “within 60 days of your birthday.”
- MedigapSeminars, a broker site, describes a 90-day window running from 30 days before to 60 days after your birthday. The same article also mentions a generic 30-day window.
The 30-day figure matches older wording of the law. The statute text on FindLaw, current as of January 1, 2026, says 60 days or more beginning with the birthday. If you’re relying on the rule, confirm your dates with the insurer and HICAP before you cancel anything.
The rule is useful for changing insurers when your attained-age premium climbs. However, it can’t get you from Medicare Advantage into Medigap. It also can’t upgrade you from Plan N to Plan G.
Some brokers argue that birthday rules push premiums up for everyone because insurers can’t screen for health. MedigapSeminars makes that case, though it’s an industry view rather than an independent study.
Federal trial rights for Medicare Advantage
Medicare.gov describes two federal “trial rights”:
- Joined Medicare Advantage at 65. If you joined a plan when first eligible at 65 and leave within the first year, you can buy certain Medigap policies without health questions.
- Dropped Medigap to try Medicare Advantage for the first time. You get a single 12-month window to return and buy back your old Medigap policy, if the same insurer still sells it.
The rule that didn’t pass
Senator Catherine Blakespear of Encinitas introduced SB 242. It would have created a yearly guaranteed-issue Medigap window open to everyone on Medicare. According to LegiScan, the bill was held in the Senate Appropriations Committee in 2025. It died on February 2, 2026.
For now, the path from Medicare Advantage back to Medigap after the trial period still usually runs through medical underwriting.
Worked Examples for San Diego Households
These examples are illustrations, not quotes. Your actual premiums and costs depend on your ZIP code, age, insurer and health.
Example 1: A healthy 65-year-old in Clairemont
Maria is newly retired and takes two generic medications. She compares two options.
Option A: Kaiser Permanente Senior Advantage San Diego. The plan lists a $0 premium, a $0 drug deductible and a $1,800 in-network cap.
- A quiet year, assuming about $300 in copays: $2,434.80 in Part B premiums + $300 = $2,734.80
- A rough year that hits the cap: $2,434.80 + $1,800 = $4,234.80
Option B: Plan G + a standalone Part D plan. She uses MoneyGeek’s implied statewide Plan G average of about $224 a month ($2,688 a year) and KFF’s national average drug-plan premium of $36 a month ($432 a year).
- A quiet year: $2,434.80 + $2,688 + $432 + the $283 Part B deductible = $5,837.80
- A rough year: essentially the same, $5,837.80, because Plan G covers her Medicare-approved costs above the deductible.
- With the lowest-priced Plan G MoneyGeek found ($166 a month), both totals drop to about $5,141.80.
On both paths, drug spending is capped at $2,100 on top of these figures.
In this example, the Kaiser HMO costs less even in a bad year. What Maria would get for Plan G’s extra cost is different: the freedom to use any Medicare provider, from Scripps to UC San Diego Health to a specialist in another state, without referrals or network changes. Many people in her situation weigh that freedom against the savings. HICAP can help her test both options with her actual doctors.
Example 2: A serious diagnosis in Rancho Bernardo
Tom is 68. In one year he has one four-day hospital stay and about $60,000 in Medicare-approved outpatient cancer treatment, imaging and specialist visits.
| Coverage | Tom’s cost for Medicare-covered care (premiums not included) |
|---|---|
| Original Medicare alone | $1,736 + $283 + 20% of $59,717 = about $13,962, with no cap |
| Original Medicare + Plan G | $283 (the Part B deductible) |
| Original Medicare + high-deductible Plan G | Up to $2,950 |
| Kaiser Senior Advantage San Diego (in-network) | Up to $1,800 |
| HumanaChoice PPO (in-network) | Up to $5,700 |
| Any plan set at the federal maximum | Up to $9,250 in-network |
Tom’s drug costs would be capped at $2,100 on any of these paths. Premiums come on top. On the Medigap side, that means a Plan G premium, which is likely above the age-65 average by 68 if the policy is attained-age priced.
Tom’s example shows why going with no supplemental coverage at all is the riskiest choice. It also shows where the real differences between Medicare Advantage and Medigap lie:
- Access. Will his oncologist and cancer center be in network, and will treatments need prior authorization?
- Flexibility. If he wants a second opinion at a different health system, can he get it?
Those are questions for the plan, and for a licensed agent or HICAP counselor, before enrollment.
San Diego-Specific Factors: Military, the Border and Travel
Military retirees and TRICARE For Life
San Diego’s large military retiree community has a third layer to consider. TRICARE says TRICARE For Life (TFL) is Medicare-wraparound coverage for TRICARE-eligible people who have both Part A and Part B. It has no enrollment fee, but you must pay Part B premiums.
For services both Medicare and TRICARE cover, TRICARE says you generally pay nothing. That’s why many local retirees don’t buy Medigap at all.
You can keep TFL if you join a Medicare Advantage plan. However, TRICARE notes that Medicare Advantage claims don’t automatically cross over, so you would file your own claims for TFL to pay its share. Some plans, like the Humana USAA Honor Giveback PPO listed in San Diego, include no drug coverage. They’re built for people who already have drug benefits elsewhere.
Crossing into Mexico for care
Many San Diegans see dentists or buy medications in Tijuana. Medicare’s April 2026 fact sheet says Original Medicare generally doesn’t pay for care outside the U.S. It also says Medicare plans can’t cover drugs bought outside the U.S.
Medigap Plans C, D, F, G, M and N include a foreign travel emergency benefit:
- It pays 80% of billed charges after a $250 yearly deductible.
- It covers emergencies that begin in the first 60 days of a trip.
- It has a $50,000 lifetime limit.
Medicare Advantage plans may offer more coverage abroad, but it varies. Check the plan’s Evidence of Coverage before a trip south of the border.
Snowbirds and frequent travelers
If you split your year between San Diego and family in another state, a local HMO’s network ends at the county line for routine care. Medigap goes wherever Medicare is accepted. A PPO sits in between, with out-of-network coverage at higher cost.
People with both Medicare and Medi-Cal
If you qualify for both programs, California’s Department of Health Care Services lists five “Medi-Medi” plans in San Diego County for 2026:
- Blue Shield TotalDual
- CommuniCare Advantage
- Kaiser Permanente Dual Complete South P1
- Molina Medicare Complete Care Plus
- SCAN Connections
These integrated plans work differently from the options in this guide.
How to Compare Your Options and Avoid Costly Mistakes
A step-by-step approach
- List your must-keep doctors and hospitals. Include specialists. Then check each plan’s directory and call the provider’s office to confirm. UC San Diego Health, for example, lists tax ID numbers so you can verify its network status with your insurer.
- Enter your drugs into Medicare Plan Finder. Compare Medicare Advantage drug coverage against standalone Part D plans.
- Check San Diego Medigap rates. Use CDI’s 2026 rate guide for your ZIP code, and note each insurer’s pricing method.
- Price out a bad year, not just a good one. Add premiums to the plan’s out-of-pocket cap, then compare that total to the Medigap option.
- Get a free second opinion. HICAP in San Diego is run by Elder Law & Advocacy and serves San Diego and Imperial counties. Call 858-565-8772 or 858-565-1392. HICAP counselors don’t sell insurance.
Mistakes that cost San Diegans money
- Choosing on premium alone. A $0 premium with a $9,250 cap and a $224-a-month Plan G protect you very differently.
- Assuming you can switch to Medigap later. Outside your first six months, the trial rights and specific guaranteed-issue events, insurers can decline you. The birthday rule only helps people who already have Medigap.
- Ignoring the fall paperwork. The October 15 to December 7, 2026 enrollment period sets your coverage for 2027. CMS says the 2027 base Part D premium rises to $41.33 as a temporary premium stabilization program ends. Read your plan’s change notice before assuming nothing changed.
- Forgetting the January reset. UC San Diego Health’s Medicare page notes that people already in Medicare Advantage get a one-time chance each year, from January 1 to March 31, to switch plans or return to Original Medicare.
Money-saving moves
- Compare at least three Medigap insurers for the same letter. MoneyGeek found Plan G premiums in California varied by about $141 a month at age 65.
- If you already have Medigap, put a reminder on your calendar before your birthday each year. That’s when you can shop other insurers’ prices for the same or lesser plan without health questions.
- Ask Medicare Advantage plans about their out-of-pocket cap first and extras second.
Frequently Asked Questions
Is Medicare Advantage or Medigap better in San Diego?
Neither is better for everyone. Medicare Advantage often costs less each month and can have a low yearly cap, especially Kaiser and some local HMOs. In return, you accept a network and prior authorization. Medigap costs more in premiums but lets you see any Medicare provider nationwide with predictable costs. Your doctors, health, travel and budget decide the fit. HICAP or a licensed agent can help compare your situation.
How much does Medigap Plan G cost in San Diego in 2026?
MoneyGeek’s 2026 California analysis priced Plan G for 65-year-olds from $166 to $307 a month. That implies a statewide average around $224. It didn’t break results out by ZIP code or gender. For San Diego-specific approved rates, use the California Department of Insurance’s 2026 Medicare Supplement rate guide. Remember that attained-age policies rise as you get older.
What is the Medicare Advantage out-of-pocket maximum for 2026?
Federal rules cap 2026 Medicare Advantage out-of-pocket costs at $9,250 for in-network care and $13,900 for combined in- and out-of-network care. Plans can set lower limits. KFF reports a national average of $5,421 in-network. Many San Diego HMOs list caps well below that. These caps cover Part A and B services only. Drug costs have a separate $2,100 limit.
Can I switch from Medicare Advantage to Medigap in California?
Yes, but guaranteed acceptance depends on timing. If you joined Medicare Advantage at 65, or dropped Medigap to try it for the first time, federal trial rights generally let you return within 12 months. After that, insurers can usually ask health questions and decline you, unless you have another guaranteed-issue event. One example is your Medicare Advantage plan ending its coverage.
What is the California birthday rule for Medigap?
California law gives current Medigap policyholders an annual open enrollment period of at least 60 days, starting on their birthday. During it, they can buy a policy with equal or lesser benefits from any insurer without health underwriting. Some websites describe 30-day or 90-day windows, reflecting older law or different interpretations. It doesn’t let you move from Medicare Advantage into Medigap.
Does UC San Diego Health accept Medicare Advantage?
Only certain plans, and often with limits. UC San Diego Health lists some SCAN, Blue Shield and Anthem HMOs, mostly for specialty care. It says it’s out of network for the Aetna and Humana PPOs. SCAN removed UC San Diego Health primary care physicians from its HMO network as of March 1, 2026. UC San Diego Health states that it accepts all Medigap plans.
Does Medicare cover medical care in Tijuana?
Generally no. Original Medicare rarely pays for care outside the U.S., and Medicare plans can’t cover drugs bought abroad. Medigap Plans C, D, F, G, M and N pay 80% of emergency care abroad after a $250 deductible, up to $50,000 over your lifetime. Some Medicare Advantage plans offer foreign emergency coverage, so check your plan’s documents before traveling.
Can I have TRICARE For Life and a Medicare Advantage plan?
Yes. TRICARE says you keep TRICARE For Life if you join Medicare Advantage, and TFL still pays second for TRICARE-covered services. However, Medicare Advantage claims don’t automatically cross over, so you may need to file claims yourself. Many military retirees simply use Original Medicare with TFL. For services both programs cover, they generally pay nothing out of pocket.
Where can I get free Medicare help in San Diego?
San Diego’s Health Insurance Counseling and Advocacy Program (HICAP) is operated by Elder Law & Advocacy. It offers free, unbiased counseling on Medicare Advantage, Medigap, Part D and billing problems. Call 858-565-8772 or 858-565-1392. HICAP counselors are registered with the California Department of Aging and don’t sell plans. You can also call 1-800-MEDICARE.
When can I change my Medicare plan for 2027?
The annual enrollment period runs October 15 through December 7, 2026, for coverage starting January 1, 2027. People already in Medicare Advantage also get a one-time switch between January 1 and March 31. Medigap has no annual enrollment period. You can apply any time, but outside protected windows like California’s birthday rule, insurers may review your health.
Next Steps
Comparing Medicare Advantage in San Diego against Medigap comes down to a trade-off.
- Medicare Advantage: lower premiums and a firm yearly cap, in exchange for a network that can change.
- Medigap: higher premiums, in exchange for freedom to use any Medicare provider and very predictable bills.
California’s birthday rule makes Medigap easier to shop once you’re in. The decision you make around age 65 still carries the most weight.
A practical next step: list your doctors and prescriptions, check them in Medicare Plan Finder, and look up your ZIP code’s rates in CDI’s Medigap guide. Then book a free HICAP appointment before the October 15 enrollment period opens. A licensed agent or advisor can tell you which option applies to your situation.
Sources
- Centers for Medicare & Medicaid Services, “2026 Medicare Parts A & B Premiums and Deductibles,” https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles, accessed September 21, 2026.
- Centers for Medicare & Medicaid Services, “Medicare Advantage and Medicare Prescription Drug Programs Expected to Remain Stable in 2026,” https://www.cms.gov/newsroom/press-releases/medicare-advantage-medicare-prescription-drug-programs-expected-remain-stable-2026, accessed September 21, 2026.
- Centers for Medicare & Medicaid Services, “Medicare Part D 2027 National Average Monthly Bid Amount Information,” https://www.cms.gov/newsroom/fact-sheets/medicare-part-d-2027-national-average-monthly-bid-amount-information, accessed September 21, 2026.
- Medicare.gov, “Compare Medigap Plan Benefits,” https://www.medicare.gov/health-drug-plans/medigap/basics/compare-plan-benefits, accessed September 21, 2026.
- Medicare.gov, “Learn How Medigap Works,” https://www.medicare.gov/health-drug-plans/medigap/basics/how-medigap-works, accessed September 21, 2026.
- Medicare.gov, “Medicare Coverage Outside the United States” (fact sheet, April 2026), https://www.medicare.gov/publications/11037-medicare-coverage-outside-the-united-states.pdf, accessed September 21, 2026.
- KFF, “Medicare Advantage in 2026: Premiums, Out-of-Pocket Limits, Supplemental Benefits, and Prior Authorization,” https://www.kff.org/medicare/medicare-advantage-in-2026-premiums-out-of-pocket-limits-supplemental-benefits-and-prior-authorization/, accessed September 21, 2026.
- FindLaw (California Insurance Code), “California Code, Insurance Code – INS § 10192.11,” https://codes.findlaw.com/ca/insurance-code/ins-sect-10192-11.html, accessed September 21, 2026.
- LegiScan, “California SB242 | 2025-2026 | Regular Session,” https://legiscan.com/CA/bill/SB242/2025, accessed September 21, 2026.
- California Department of Insurance, “2026 Guide On Medicare Supplement Insurance,” https://interactive.web.insurance.ca.gov/apex_extprd/f?p=111%3A30, accessed September 21, 2026.
- MoneyGeek, “Best Medicare Supplement Plans in California (2026),” https://www.moneygeek.com/insurance/health/best-medicare-supplement-california/, accessed September 21, 2026.
- Medicare.org, “Medicare Advantage Plans in San Diego County, CA: Your Complete 2026 Guide,” https://www.medicare.org/medicare-advantage-plans/california/san-diego/, accessed September 21, 2026.
- MedicareAdvantage.com, “2026 Medicare Advantage Plans in San Diego County, California,” https://www.medicareadvantage.com/plans-by-state/california/san%20diego, accessed September 21, 2026.
- UC San Diego Health, “Medicare Plans Accepted at UC San Diego Health,” https://health.ucsd.edu/insurance-billing/accepted-health-plans/medicare/, accessed September 21, 2026.
- County of San Diego Health & Human Services Agency, “Financial/Legal and Health Insurance Services,” https://www.sandiegocounty.gov/content/sdc/hhsa/programs/ais/Older-Adults/Financial-Legal-Health-Insurance-Services.html, accessed September 21, 2026.
- TRICARE, “TRICARE For Life,” https://tricare.mil/tfl, accessed September 21, 2026.
- TRICARE, “Will I lose my TRICARE For Life benefits if I sign up for a Medicare Advantage plan?,” https://tricare.mil/FAQs/TRICARE-with-Medicare/TRIMed_Advantage, accessed September 21, 2026.
- California Department of Health Care Services, “Medicare Medi-Cal Plan List,” https://www.dhcs.ca.gov/provgovpart/Pages/Medicare-Medi-Cal-Plan-List.aspx, accessed September 21, 2026.
- MedigapSeminars, “Medicare Supplement Birthday Rule: a Disappointing Surprise?,” https://medigapseminars.org/medicare-supplement-birthday-rule/, accessed September 21, 2026.
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