HMO and PPO in Medicare Advantage: how the two plan types work

Original Medicare (Parts A and B) has no network. You can see any provider who accepts Medicare. When you join a Medicare Advantage plan, you trade that open access for a structured network in exchange for additional benefits and, often, a lower monthly premium.

An HMO builds care around a primary care physician (PCP). You choose one provider who coordinates your care and, in most cases, writes referrals before you see a specialist. See a doctor outside the plan network and the plan generally pays nothing, except in a true emergency.

That tight structure has practical benefits. Because the plan controls the network, it can usually negotiate lower cost-sharing for in-network visits. The administrative path is predictable: you call your PCP, get a referral if needed, and the claim routes through a contracted provider.

A variant called an HMO-POS (point-of-service) adds a limited out-of-network option, typically at significantly higher cost-sharing. It softens the hard boundary without going all the way to a PPO structure.

A PPO gives you two tiers: in-network providers at lower cost and out-of-network providers at higher cost. You do not need a PCP designation, and you do not need referrals before seeing a specialist. Any provider who accepts Medicare and the plan's out-of-network terms is accessible.

That flexibility costs something. PPO premiums tend to run higher than comparable HMOs in the same market, and the out-of-network cost-sharing can be substantial. The plan still has a preferred network, and staying in it keeps your costs predictable.

Both HMOs and PPOs must stay within the federal MOOP (maximum out-of-pocket) caps that CMS (the Centers for Medicare and Medicaid Services) sets each year. In 2026, the in-network MOOP cap is $9,250; plans may set their own limits below that ceiling. The combined in-network plus out-of-network MOOP cap in 2026 is $13,900 for PPOs that include out-of-network coverage. According to KFF, the 2026 enrollment-weighted average in-network MOOP across Medicare Advantage plans is $5,421, meaning most enrollees are in plans with limits well below the federal ceiling.

Once you hit the MOOP, the plan covers 100% of covered in-network costs for the rest of the year. That cap does not exist in Original Medicare, where the Part B coinsurance of 20% has no annual ceiling.

Prior authorization is another cost-control lever both plan types use. Under CMS rule CMS-0057-F, which took effect in 2026, a standard prior-authorization decision must come within 7 calendar days. Expedited decisions, when a delay would seriously harm your health, must come within 72 hours, and any denial must include a specific reason.

A few practical questions narrow the choice quickly.

Do your current doctors participate in the plan network? With an HMO, an out-of-network visit is almost always entirely your expense. With a PPO, you still pay more out of network, but the plan contributes. If you have established specialists you want to keep, verify their participation status before enrolling.

Do you travel frequently or split time between states? HMOs are usually county-level networks. PPOs have broader footprints and recognize out-of-network providers, which matters if you spend months in a second location.

How often do you need specialist care? If you see multiple specialists regularly, the HMO referral step adds a coordination layer. Some people find it useful; others find it burdensome. PPOs skip that step entirely.

What is the premium difference? A lower HMO premium only saves money if you stay in network. A higher PPO premium may cost less overall if you regularly use out-of-network providers and the out-of-pocket difference is smaller than the premium gap.

Neither plan type is universally better. An HMO in a dense urban market with a broad network may cover your care more completely than a PPO in a rural area with a thin preferred tier.

You can join or switch Medicare Advantage plans during the Annual Enrollment Period (AEP), which runs October 15 to December 7, with coverage starting January 1. If you are already in a Medicare Advantage plan and want to switch, or return to Original Medicare, the Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 to March 31 each year.

Choosing the wrong plan type is not permanent. If an HMO's network no longer suits you, you can switch to a PPO at the next AEP or during the MA OEP. Keeping track of your plan's annual Notice of Change, which arrives each fall, tells you about network or cost changes before the AEP opens.

To find out more about coverage, please contact us to discuss plan options.