Hoag, Providence, UCI Health, MemorialCare, or Kaiser: How Orange County Health Systems Work With Medicare

If you live in Orange County, the Medicare question that matters most is usually not “which plan has the lowest premium.” It is: can I keep seeing my doctors at Hoag, Providence St. Joseph, UCI Health, MemorialCare, or Kaiser Permanente?

Orange County has dozens of Medicare plan options and several large health systems competing for the same patients, which makes networks — not brochures — the deciding factor for most people. This guide explains how the county’s major health systems fit into Medicare, why the “medical group” line in a plan directory matters, and how to check before you enroll or make a change.

The health systems most Orange County beneficiaries use

• Hoag — Hoag Hospital Newport Beach and Hoag Hospital Irvine, plus health centers and urgent care locations around the county. Hoag has operated as an independent system since its affiliation with Providence ended in January 2022.
• Providence — Providence St. Joseph Hospital in Orange, Providence St. Jude Medical Center in Fullerton, and Providence Mission Hospital in Mission Viejo and Laguna Beach, along with affiliated medical groups such as St. Joseph Heritage, St. Jude Heritage, and Mission Heritage.
• UCI Health — the county’s academic health system: UCI Health – Orange (the former UCI Medical Center), UCI Health – Irvine (opened in December 2025), and community hospitals including those in Fountain Valley, Los Alamitos, and Placentia.
• MemorialCare — Orange Coast Medical Center in Fountain Valley and Saddleback Medical Center in Laguna Hills, with MemorialCare Medical Group and an affiliated network of independent physicians.
• Kaiser Permanente — an integrated system where the health plan and the doctors are the same organization, with Orange County medical centers in Anaheim and Irvine.

City of Hope also opened a cancer specialty hospital in Irvine in late 2025, and community hospitals serve the rest of the county. Which of these you can use depends on how you receive your Medicare coverage.

Medicare Advantage in Orange County: the medical-group layer

Medicare Advantage (Part C) plans are offered by private insurers and typically use a network of local providers. In Orange County, many of these plans are HMOs, and HMOs in California add a layer that national websites rarely explain: you don’t just choose a plan — you (or the plan) also assign you to a medical group or IPA. That medical group, not the insurer, largely decides which specialists and hospitals you can use.

Orange County’s medical groups include Optum (which includes the former Monarch HealthCare), the Providence-affiliated Heritage medical groups, MemorialCare Medical Group, and the physician groups affiliated with Hoag and UCI Health. Two neighbors on the identical plan can have very different access depending on which medical group each is assigned to. So when you check a plan, check three things:

1. Is my doctor in the plan’s current directory?
2. Which medical group is my doctor listed under in that plan?
3. Does that medical group admit to the hospital I want — Hoag, St. Joseph, St. Jude, Mission, UCI Health, Orange Coast, Saddleback, or another?

Two Orange County details trip people up:

• Hoag and Providence are separate systems. They were affiliated for about a decade, but that ended in January 2022. A plan or medical group that includes Providence doctors does not automatically include Hoag, and the reverse is also true. Check each one by name.
• One system can mean several campuses. UCI Health now includes the academic medical center in Orange, the new Irvine hospital, and community hospitals including those in Fountain Valley, Los Alamitos, and Placentia. If a specific location matters to you, confirm that location — not just the system name — in the plan’s directory.

Kaiser Permanente works differently again: its Medicare Advantage plans are built around Kaiser’s own doctors and facilities, so they generally suit people who want to receive their care within the Kaiser system.

Networks are not permanent — and Orange County has seen that recently. Providence announced on its own website that, effective January 1, 2026, the Providence Clinical Network — which includes the St. Joseph Heritage, Mission Heritage, and St. Jude Heritage medical groups — would no longer be contracted with one large national insurer’s Medicare Advantage plans. According to that insurer’s own notice, the change applies to its individual Medicare Advantage HMO plans, while Providence hospitals remain in network and employer group retiree plans were not affected. A second change is already scheduled for 2027. Hoag says on its own website that its contract with one Medicare Advantage HMO insurer ends December 31, 2026, and that Hoag providers, services, and facilities will be out of network for that insurer’s Medicare Advantage HMO members beginning January 1, 2027. Changes also run the other way. On September 8, 2026, another Medicare Advantage insurer announced an expanded arrangement with Hoag. According to that announcement, beginning January 1, 2027, members of select HMO plans will have in-network access to Hoag Hospital Newport Beach, Hoag Hospital Irvine, Hoag Medical Group, and Hoag Physician Partners, among other Hoag locations in Orange County. “Select” matters: it is not every plan that insurer offers, so look for your exact plan name in that plan’s 2027 provider directory and confirm with the plan. If you use Hoag, read Hoag’s insurance page and confirm your 2027 plan’s network before Annual Enrollment ends on December 7. The lesson is bigger than any one contract: a plan can keep a hospital and lose the doctors’ medical group, or the reverse.

That is exactly why the Annual Notice of Change (ANOC) your plan mails each September deserves a careful read. Our guide to reading your Annual Notice of Change walks through what to look for, and if your plan is ending, see what to do when a Medicare Advantage plan is discontinued. For the plan-comparison side — HMO vs. PPO, drug coverage, and costs — see how to compare Medicare Advantage plans in Orange County.

What to do if your plan will no longer include your doctor or hospital

If a network change like the ones above affects you, these are the options to look at. None of them is automatic, so confirm each one before you act.

• Stay in your plan and choose another in-network provider.
• Switch plans during Annual Enrollment (October 15 to December 7), after confirming in the new plan’s 2027 provider directory, and with the provider’s office, that it includes that provider. For an HMO, check the medical group too. The change takes effect January 1, and networks can still change during the year.
• Return to Original Medicare during the same window. Confirm the provider accepts Original Medicare. You need a separate Part D plan to keep drug coverage, and a Medigap insurer can decline you unless you have a guaranteed-issue or open enrollment right.
• Ask your current plan about continuity of care if you are in the middle of treatment. For example, Hoag’s notice about its contract with one Medicare Advantage HMO insurer ending December 31, 2026 (read October 7, 2026) says affected patients may have the right to keep seeing their provider for a designated period, and that the plan decides who is eligible.
• Check California’s guaranteed-issue rule for Medigap. California law may give you a guaranteed-issue right to a Medigap policy, generally from your plan’s insurer or a related company first, when your plan ends its contract with a provider who is currently treating you for a reason other than quality of care. The conditions and limits are in our guide to switching from Medicare Advantage to Medigap in California. Whether it applies to your situation is for the Medigap insurer to confirm, so get its answer in writing before you leave your plan, and check with HICAP or the California Department of Insurance.

If you miss December 7, people enrolled in a Medicare Advantage plan can switch plans or return to Original Medicare once during the Medicare Advantage Open Enrollment Period, January 1 to March 31.

If you have both Medicare and Medi-Cal in Orange County

CalOptima Health, a public agency, is Orange County’s public Medi-Cal health plan. It also offers CalOptima Health OneCare Complete (HMO D-SNP), a type of Medicare Advantage plan that combines Medicare and Medi-Cal benefits in a single plan. To qualify, you must live in Orange County, have Medicare Parts A and B, have full Medi-Cal with no share of cost, and be age 21 or older.

It is one option among the dual-eligible special needs plans that may be available in the county; whether it, or any plan, fits you depends on your doctors, prescriptions, and needs. (This is a description, not a recommendation.) If you have both programs, free counseling from HICAP — in Orange County, a program of the Council on Aging – Southern California — is a good first call.

Original Medicare + Medigap: system choice without networks

If provider flexibility is your priority, the other route is Original Medicare with a Medicare Supplement (Medigap) policy. Medigap works alongside Parts A and B and lets you see any provider in the country that accepts Medicare — which includes the large Orange County systems for Medicare-participating services. There is no network to check and no medical-group assignment.

The trade-offs: Medigap has its own monthly premium, and it doesn’t include drug coverage, so most people pair it with a standalone Part D plan. California also gives Medigap policyholders the Birthday Rule — a window of at least 60 days each year, starting on your birthday, to switch to another Medigap plan of equal or lesser benefits without medical underwriting. For a fuller comparison, see Medicare Advantage vs. Medicare Supplement.

How to check your doctors before you enroll or switch

1. Make your list: every doctor you see, the hospital you’d choose, and your prescriptions with dosages.
2. Search the plan’s current-year provider directory for each doctor, and note the medical group shown next to your primary doctor.
3. Check the health system’s own insurance page. Hoag, Providence, UCI Health, and MemorialCare each publish information about accepted plans. Hoag’s page, for example, advises patients to confirm directly with the health plan.
4. Call the doctor’s office and ask directly: “Which Medicare Advantage plans and medical groups are you accepting for next year?”
5. Re-check every fall. Between October 15 and December 7 — the Annual Enrollment Period (AEP) — you can join, switch, or drop a Medicare Advantage or Part D plan for the following year. 2027 plan details are now in Medicare’s Plan Finder. Our Annual Enrollment guide for Southern California has a month-by-month checklist, and what’s changing in 2027 covers the numbers published so far.

If you’d rather not do this alone, this is exactly what an independent Medicare broker in Orange County does: check your doctors, medical groups, and prescriptions against the plans I represent in your ZIP code, at no cost to you, because brokers are paid by the insurance carriers. New to Medicare in the county? Start with Medicare in Orange County: enrollment and local help.

More local guides: how health systems work with Medicare in Los Angeles, Orange County, and San Diego.

Frequently asked questions

Are Hoag and Providence St. Joseph part of the same health system?

No. Hoag and Providence ended their affiliation in January 2022 and operate as separate systems. A Medicare Advantage plan or medical group that includes one does not automatically include the other, so check each by name in the plan’s current directory.

Which Medicare Advantage plans do Hoag, Providence, and UCI Health accept for 2027?

It depends on the specific plan and medical group, and it can change every year, so no single list stays accurate. As of October 7, 2026, Hoag’s own insurance page marks certain Medicare Advantage HMO plans with a contract end date of December 31, 2026 and lists a different plan as effective January 1, 2027. 2027 plan details are now available in Medicare’s Plan Finder. Search for your doctor and their medical group in each plan’s 2027 provider directory, check the health system’s own insurance page, and ask the office directly which plans they will accept.

Which hospitals are part of UCI Health?

In Orange County, UCI Health includes UCI Health – Orange (the former UCI Medical Center), UCI Health – Irvine, which opened in December 2025, and community hospitals in Fountain Valley, Los Alamitos, and Placentia. Confirm the specific location you want in a plan’s directory, not just the system name.

What is a medical group, and why does it matter in Orange County?

With most California HMO plans, your primary doctor belongs to a medical group or IPA that coordinates referrals to specialists and hospitals. A medical group can contract with some hospitals and not others, so the medical group, not just the plan name, determines where you can be treated.

I have both Medicare and Medi-Cal in Orange County. What should I look at?

People with both programs may qualify for a dual-eligible special needs plan (D-SNP), a type of Medicare Advantage plan that coordinates Medicare and Medi-Cal benefits. CalOptima Health, the county’s public Medi-Cal plan, offers one; others may be available. HICAP offers free, unbiased counseling, and Medicare.gov lists every plan in your ZIP code.

Does it cost more to get help from a broker when comparing Orange County plans?

No. Working with a licensed independent broker costs you nothing and doesn’t change your premium, because brokers are paid by the insurance carriers. You always remain free to compare every plan yourself at Medicare.gov.

Sources & official references

• Medicare.gov — Understanding your Medicare Advantage plan’s provider network (PDF)
• Medicare.gov — Joining a plan (enrollment periods)
• Medicare.gov — Plan Finder (2027 plans)
• Medicare.gov — Medigap (Medicare Supplement Insurance)
• Hoag — Insurance accepted
• Hoag — Providence and Hoag agree to end affiliation (January 10, 2022)
• UCI Health — UCI Medical Center becomes UCI Health – Orange (July 1, 2025)
• UCI Health — UCI Health – Irvine
• MemorialCare — Health insurance guide
• Providence — Insurance accepted (Southern California)
• CalOptima Health — OneCare (plan’s own site, cited for identification only)
• Council on Aging – Southern California — HICAP (Orange County)
• California HICAP — free, unbiased Medicare counseling (California’s State Health Insurance Assistance Program (SHIP)), 1-800-434-0222

Last reviewed: October 2026. Educational information only, not individualized advice. Health-system, medical-group, and plan names are used for identification only and do not imply affiliation or endorsement. Plan networks and benefits change annually — confirm current details with the plan and at Medicare.gov. This is a non-government resource and is not affiliated with or endorsed by Medicare.gov or the federal Medicare program. We do not offer every plan available in your area. Currently we represent 12 organizations which offer 442 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. For free, unbiased counseling, contact your local State Health Insurance Assistance Program (SHIP) — in California, the Health Insurance Counseling and Advocacy Program (HICAP), 1-800-434-0222. Matt Medicares Insurance is an independent insurance brokerage and is not affiliated with or endorsed by Medicare, the Centers for Medicare & Medicaid Services, or any government agency.