ACO REACH vs Medicare Advantage: What Changes in 2027
Reviewed October 16, 2026. ACO REACH and Medicare Advantage are very different things. ACO REACH is a Medicare payment model for doctors and other providers: if you’re aligned to a REACH ACO, you stay in Original Medicare, keep your Medicare card and can still see any provider that accepts Medicare. Medicare Advantage is a private health plan you choose to join, with its own network, rules and extra benefits. ACO REACH ends on December 31, 2026, and CMS’s new LEAD model takes over on January 1, 2027.
Quick answer: You don’t enroll in ACO REACH, so it can’t replace a Medicare Advantage plan. If your doctor is in an ACO, your coverage is still Original Medicare (plus any Medigap or Part D plan you have). If you want a plan with a network, an out-of-pocket limit and extras like dental or an OTC allowance, that’s Medicare Advantage, and you can switch during Open Enrollment, October 15 to December 7, 2026, for coverage starting January 1, 2027.
ACO REACH vs Medicare Advantage at a glance
| ACO REACH (through 2026) / LEAD (from 2027) | Medicare Advantage | |
|---|---|---|
| What it is | A CMS Innovation Center payment model for groups of providers | A private health plan approved by Medicare (Part C) |
| Do you enroll? | No. You’re aligned to an ACO through your doctor, based on your claims or your choice of primary provider | Yes. You choose a plan and enroll |
| Your coverage | Original Medicare (Part A and Part B) | The plan replaces how Original Medicare pays your claims |
| Choice of providers | Any provider that accepts Medicare, in or out of the ACO | Usually a network (HMO or PPO rules) |
| Medigap | You can keep a Medigap policy | Medigap can’t be used with the plan |
| Extra benefits | Limited model incentives (for example, help with Part B cost sharing) | Often dental, vision, hearing, fitness and OTC benefits |
| Out-of-pocket limit | None in Original Medicare | Every plan has a yearly limit for covered Part A and B services |
What is ACO REACH?
ACO REACH (Realizing Equity, Access, and Community Health) is a model run by the CMS Innovation Center. It started on January 1, 2023 and covers four performance years, 2023 through 2026, and it no longer accepts new applications. (CMS: ACO REACH)
An accountable care organization (ACO) is “a group of doctors, hospitals, and/or other health care providers that accept Original Medicare” and work together to coordinate care. ACOs that keep costs down while meeting quality standards can share in the savings, and in REACH they can also share in losses. In 2026, 74 REACH ACOs serve about 1.7 million people with Traditional Medicare. (CMS, February 2026)
How you end up in an ACO
You’re aligned to a REACH ACO in one of two ways: claims-based alignment, when most of your primary care comes from ACO providers, or voluntary alignment, when you name an ACO doctor as your main provider. Either way, Medicare.gov says your Medicare benefits and rights stay the same, including the “freedom to visit any Medicare provider (even if that provider isn’t part of an ACO).” You can ask Medicare not to share your claims data with the ACO by calling 1-800-MEDICARE. (Medicare.gov: ACOs)
What changes in 2027: ACO REACH ends, LEAD begins
Medicare.gov states that ACO REACH “ends December 31, 2026” and that the LEAD model begins January 1, 2027. LEAD (Long-term Enhanced ACO Design) is a 10-year voluntary model that CMS calls “a successor to the ACO REACH Model.” It runs from January 1, 2027 through December 31, 2036. (CMS: LEAD model)
- Who joins: CMS expects current REACH ACOs and other ACOs, providers new to ACOs, and providers serving underserved areas such as federally qualified health centers and rural health clinics.
- Alignment: the same idea as REACH. You’re aligned based on your claims history or because you chose an ACO-affiliated primary provider. (CMS LEAD overview, PDF)
- Risk options: Professional Risk (up to 50% of savings and losses) or Global Risk (up to 100%).
- Beneficiary incentives: CMS lists Part B cost-sharing support and, by 2029, a Part D premium buy-down.
For you as a patient, the practical point doesn’t change in 2027: an ACO model is not a health plan. If your doctor moves from REACH to LEAD, you’re still in Original Medicare.
How Medicare Advantage is different
Medicare Advantage plans are offered by private insurers such as Humana, UnitedHealthcare, Aetna and Wellcare. You enroll during your Initial Enrollment Period or Open Enrollment, and the plan then covers your Part A and Part B services, usually with Part D drug coverage built in. Medicare.gov is clear that “ACOs are not Medicare Advantage Plans.”
- Networks: HMOs generally require in-network care and referrals; PPOs let you go out of network at a higher cost. See Medicare Advantage HMO vs PPO.
- Out-of-pocket maximum: each plan caps what you pay for covered medical services in a year.
- Extras: many plans include routine dental, vision, hearing, fitness and OTC allowances. See Medicare Advantage dental coverage.
- Prior authorization: plans can require approval before some services, which Original Medicare generally doesn’t.
Costs in 2026 and 2027
If you’re aligned to an ACO, you pay normal Original Medicare costs. For 2026 the Part B premium is $202.90 a month and the Part B deductible is $283; after that you generally pay 20% of the Medicare-approved amount. (CMS 2026 fact sheet) CMS hasn’t published the 2027 Part B premium and deductible yet; Medicare says 2027 amounts will be released in the fall. Many people in Original Medicare add a Medigap policy and a Part D plan to fill the gaps.
With Medicare Advantage you still pay the Part B premium (unless your plan has a Part B giveback), plus the plan’s premium, copays and coinsurance up to its out-of-pocket limit. For 2027 drug coverage, the Part D out-of-pocket cap rises to $2,400, from $2,100 in 2026. (Medicare.gov: Part D costs)
Which is right for you in 2027?
You don’t pick between ACO REACH and Medicare Advantage the way you pick between two plans. The real choice is Original Medicare (where your doctor may be in an ACO) versus Medicare Advantage.
- Original Medicare plus Medigap may suit you if you want to see any provider nationwide, travel often, or want predictable costs with a Medigap policy. See Medigap Plan G vs Plan N.
- Medicare Advantage may suit you if you’re comfortable with a network, want a yearly out-of-pocket cap and value extra benefits. Compare 2027 plans on Medicare Plan Finder.
Before you switch, check that your doctors and drugs are covered and read each plan’s 2027 Summary of Benefits. Our annual Medicare plan review checklist and Open Enrollment guide walk through the steps.
Frequently asked questions
Is ACO REACH a Medicare Advantage plan?
No. ACO REACH is a payment model for providers who treat people in Original Medicare. Medicare.gov says ACOs are not Medicare Advantage plans.
Is ACO REACH ending?
Yes. ACO REACH ends December 31, 2026. CMS’s LEAD model, a 10-year successor, starts January 1, 2027.
Can I be in an ACO and a Medicare Advantage plan at the same time?
ACO REACH and LEAD align people with Traditional Medicare. If you join a Medicare Advantage plan, the plan manages your care instead.
Can I still see doctors outside the ACO?
Yes. Being aligned to an ACO doesn’t limit you to its providers. You can see any provider that accepts Medicare.
What is the Medicare Shared Savings Program?
It’s Medicare’s permanent ACO program. In 2026, 511 Shared Savings Program ACOs serve 12.6 million people. (CMS)
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