The letters attached to a health plan describe its network rules, not its benefit level. Two plans with identical deductibles can behave very differently depending on which of these four types they are.
Every one of them answers the same two questions. Once you know the answers, the acronyms stop being mysterious.
The two questions that define a plan type
Do you need a referral to see a specialist? Some plans require a primary care provider to coordinate your care and issue referrals before the plan will pay a specialist. Others let you book directly.
Is out-of-network care covered? Some plans pay a reduced share for providers outside the network. Others pay nothing at all except in an emergency.
Those two answers produce four combinations, and the four combinations are the four plan types.
| Plan type | Out-of-network coverage | Referral needed for specialists |
|---|---|---|
| HMO | No, except emergencies | Yes |
| EPO | No, except emergencies | No |
| PPO | Yes, at higher cost | No |
| POS | Yes, at higher cost | Yes |
HMO: Health Maintenance Organization
An HMO generally limits coverage to providers who work for or contract with the HMO, and it typically will not cover care outside that network except in an emergency. It may also require you to live or work in its service area to be eligible.
HMOs usually route care through a primary care provider, who handles routine care and issues referrals for services they do not provide themselves. That structure is often described as integrated care with an emphasis on prevention.
The practical consequence: if you see an out-of-network provider without an emergency, you may be responsible for the entire bill, and that spending typically does not count toward your deductible or out-of-pocket maximum.
EPO: Exclusive Provider Organization
An EPO covers services only when you use providers in the plan's network, again with an exception for emergencies. Unlike an HMO, an EPO generally does not require a referral to see a specialist.
It is, in effect, the HMO network rule without the referral requirement. You choose your own specialists, but you choose them from the network list.
PPO: Preferred Provider Organization
A PPO contracts with a network of providers and pays more when you use them. You can also use providers outside the network for an additional cost, and you do not need a referral to do so.
Two things about that out-of-network access are worth being precise about:
- It costs more, in more than one way. Out-of-network care typically carries higher coinsurance, and it frequently applies against a separate and higher deductible and out-of-pocket maximum.
- The provider has not agreed to the plan's rates. Outside the protections described in in-network, out-of-network and surprise bills, an out-of-network provider may bill you for the difference between their charge and what your plan pays.
Premiums are generally higher for a PPO than an HMO, which reflects the broader provider flexibility rather than a richer benefit package.
POS: Point of Service
A POS plan pays less when you go outside the network, like a PPO, but requires a referral from your primary care provider to see a specialist, like an HMO.
It is the combination people most often misread, because the out-of-network option makes it feel like a PPO right up until a specialist claim is denied for want of a referral.
Network type is separate from metal level
This trips up a lot of shoppers. On the marketplace, a plan's network type and its metal level are independent.
You can find a bronze HMO and a bronze PPO, a gold EPO and a gold POS. The metal level describes roughly what share of costs the plan is designed to cover, while the network type describes which providers you may use and under what conditions. Both matter, and neither substitutes for the other. The metal levels are covered in health plan metal tiers explained.
Every marketplace plan, regardless of network type, must cover the same ten essential health benefits. Network type changes who you can see, not what is covered.
What to check before you enroll
Network directories change, and the single most expensive assumption in health insurance is that a provider is in network when they are not.
- Search the plan's own directory, not a general search engine, and confirm the specific location and practice, since a physician can be in network at one facility and not another.
- Call the provider's billing office and ask whether they are contracted with that specific plan for the coming plan year. Being contracted with an insurer is not the same as being contracted with every plan that insurer offers.
- Check the hospital as well as the doctor, because a facility and the clinicians who practice there contract separately.
- Ask about the service area if you split time between locations, since HMO eligibility can depend on where you live or work.
- Check the prescription formulary, which is a separate list from the provider network and has its own tiers.
- Ask how out-of-area care is handled for a student, a frequent traveler, or a household spread across states. Some plans have national arrangements and some do not.
Choosing between them
There is no plan type that is better in general. The trade is between flexibility and structure, and the right side of that trade depends on facts about your own household.
A narrow network with a referral requirement may work well when your care is concentrated in one health system and you value a coordinated primary care relationship. Broader out-of-network access may matter more when you have established specialists across systems, live near a state line, or expect to need care away from home.
Availability differs sharply by geography. Some counties offer several network types and some offer only one. What is available where you live is a fact about your local market rather than a preference you get to exercise.
Plan designs, network composition and availability vary by insurer and by state, and can change from one plan year to the next. For anything specific to your situation, talk to a licensed agent, the insurer directly, or your state Department of Insurance. To start, you can request health insurance quotes and get connected with licensed carriers and agents offering plans in your area.