When you buy health insurance, one of the first choices you're asked to make is plan type. HMO. PPO. EPO. POS. The letters don't mean much on their own — but they determine everything from which doctors you can see to how much you'll pay to whether you need a referral to see a specialist.
Most people pick a plan based on premium price alone and only find out the constraints when they actually need care. This guide breaks down each plan type clearly so you can make a real choice at enrollment — and understand exactly what your plan requires when you need it.
of people with private health insurance are in a managed care plan (HMO or EPO) and don't realize there's a difference — or what network restrictions actually mean at the point of care (KFF Employer Health Benefits Survey, 2025).
The Four Plan Types, Explained
Each plan type controls three things: which providers you can use, how much you pay in different scenarios, and whether you need permission to see a specialist.
HMO — Health Maintenance Organization
HMOs require you to pick a primary care physician (PCP) and get a referral from that PCP before seeing any specialist. They only cover care delivered by in-network providers — going outside the network means you pay the full bill. In exchange, HMOs typically have the lowest premiums and lowest copays of any plan type. If you want to see a dermatologist, cardiologist, or any other specialist, your PCP has to send a referral first.
PPO — Preferred Provider Organization
PPOs give you the most freedom. You can see any doctor — in-network or out-of-network — without a referral. Going to an in-network provider costs you less; going out of network costs more, but the plan still contributes toward the bill. PPOs have higher premiums than HMOs but more flexibility. If you want to self-refer to a specialist without asking your PCP, a PPO lets you do that. If you want to keep your current specialist who happens to be out of network, a PPO is usually the only option that covers them at all.
EPO — Exclusive Provider Organization
An EPO is a hybrid. Like a PPO, you don't need a referral to see a specialist — you can book directly with any in-network specialist you choose. Like an HMO, you only have coverage for in-network providers — going out of network is entirely at your own expense with no plan contribution. EPOs sit between HMO and PPO in cost: lower premiums than PPOs, slightly higher than HMOs, but no referral hassle and no coverage for out-of-network care.
POS — Point of Service
POS plans combine HMO and PPO features. You pick a PCP who provides referrals — like an HMO — but you can also go out of network for some coverage, paying a higher share of the cost. POS plans offer more flexibility than HMOs for out-of-network care, but typically cost more than HMOs. They're less common than the other three types but still available, particularly through some employer plans.
Side-by-Side Comparison
Here's how each plan type stacks up across the five dimensions that matter most:
| Feature | HMO | PPO | EPO | POS |
|---|---|---|---|---|
| Primary care required | Yes — must choose a PCP | No | No | Yes — must choose a PCP |
| Referral needed for specialists | Yes | No — self-refer freely | No — self-refer in-network | Yes, for in-network; optional for out-of-network |
| In-network coverage | Full coverage | Full coverage, lower cost-share | Full coverage | Full coverage, lower cost-share |
| Out-of-network coverage | None — you pay 100% | Partial — plan pays some, you pay more | None — you pay 100% | Partial — higher cost-share required |
| Typical premium level | Lowest | Highest | Middle | Middle to high |
| Best for | Budget-conscious, healthy people who don't mind PCP coordination | People who want maximum flexibility or see out-of-network providers | People who want no referrals without paying PPO prices | People who want PCP coordination with some out-of-network flexibility |
In-Network vs. Out-of-Network: Why It Matters More Than You Think
Every health insurance plan has a network — a set of doctors, hospitals, labs, and other providers that have contracted with the insurer to provide care at negotiated rates. These negotiated rates are significantly lower than what providers charge uninsured patients. That's the whole point of being "in-network."
When you see an in-network provider:
- Your copay or coinsurance is based on the contracted (lower) rate
- The provider cannot "balance bill" you for the difference between the bill and the allowed amount
- The plan's cost-sharing applies normally
When you see an out-of-network provider:
- Your plan may not cover anything, or may cover only a small fraction
- The provider can bill you for the full amount — the difference between their charge and what insurance allowed — in a practice called balance billing
- Your in-network deductible and OOP max don't apply to out-of-network costs
For HMO and EPO plans specifically, going out of network means you have zero coverage. You pay 100% of whatever the provider charges. There is no safety net.
If you've already received an out-of-network bill and didn't know it was out-of-network, our out-of-network billing guide covers exactly what options you have — including No Surprises Act protections that may apply.
Understand your coverage before you need it
Enter your plan type and the care you're considering — ClaimSage's Benefits Navigator explains what's covered, what requires authorization, and what it'll cost you.
Check my benefits → Estimate my costsWhat "In-Network" Actually Looks Like at the Doctor's Office
Here's how it plays out in practice. Say you need an MRI:
With an in-network provider: The MRI center bills $2,400. Your insurer has a contracted rate of $900 with that center. Your plan's cost-sharing applies to the $900 rate — if you've met your deductible and the plan covers MRI at 20% coinsurance, you pay $180. The insurer pays the difference.
With an out-of-network provider (on a PPO): The MRI center bills $2,400. Your insurer applies an "allowed amount" for out-of-network care — say $600. Your plan covers 60% of that $600, so it pays $360. You're responsible for the rest: $600 - $360 = $240, plus the $1,800 difference between the $2,400 charge and the $600 allowed amount. Total you pay: $2,040 instead of $180.
On an HMO or EPO, the out-of-network provider isn't covered at all. You'd owe the full $2,400.
This is why using in-network providers is the single biggest lever for reducing health care costs — more impactful than any deductible or coinsurance percentage. The math is stark.
Referrals: How They Work and When They Matter
The referral requirement is the most visible constraint of HMO plans. Here's the process:
- You schedule an appointment with your PCP for a problem you think needs a specialist
- The PCP evaluates you and decides whether to refer you to a specialist
- If the PCP refers you, the HMO authorizes the visit — the plan will cover it
- If you self-refer (go to a specialist without PCP authorization), the HMO typically denies the claim and you pay out of pocket
This process exists to control costs and prevent unnecessary specialist visits. In practice, most PCP referrals are approved — but the process adds time and friction. If you have a condition that requires ongoing specialist monitoring (chronic conditions, post-surgical care, fertility treatments), that friction compounds quickly.
Some HMOs have "open access" or "direct access" provisions that allow you to see certain specialists — often gynecologists, mental health providers, or dermatologists — without a referral. Check your plan documents to see what's covered without authorization.
PPOs and EPOs have no referral requirement. You book directly with any in-network specialist. The tradeoff for that flexibility is higher monthly premiums.
Which Plan Type Should You Choose?
There's no universally correct answer — it depends on your health needs, budget, and which doctors you want to keep. Here are the main scenarios:
Choose an HMO if:
- You're generally healthy and don't expect to need frequent specialist care
- You want the lowest possible monthly premium
- Your current doctors are in the HMO's network
- You're comfortable coordinating through a PCP and don't mind the referral process
Choose a PPO if:
- You see specialists regularly or have a complex health condition
- You want to keep doctors who are out of network
- You value the ability to self-refer without PCP involvement
- You can afford higher monthly premiums in exchange for more flexibility
Choose an EPO if:
- You want to see specialists directly without referrals but don't want to pay PPO prices
- All your current providers are in-network (so the out-of-network restriction doesn't affect you)
- You're comfortable with network-only coverage in exchange for lower premiums than a PPO
For a deeper comparison of actual dollar costs — premiums, deductibles, and out-of-pocket maximums across all plan types — see our guide to Deductibles, Copays, and Coinsurance.
Check what your plan already paid
Upload a past EOB to see how your plan processed in-network vs. out-of-network claims — and whether balance billing already hit your account.
Read my EOB →Network Size: Not All Plans Are Equal
Networks vary significantly between insurers and even between plan types from the same insurer. An HMO with a broad network can actually give you more in-network access than a narrow-network PPO. Don't assume a plan type tells you anything about network size — check directly.
Key things to verify about any plan's network:
- Is your PCP in-network? This determines whether you need to switch doctors or pay out of network rates
- Are your specialists in-network? If you have ongoing specialist relationships, confirm they're covered before you enroll
- What hospitals are in-network? For any planned surgery or hospitalization, the network status of the facility matters enormously
- Is the network HMO-only, or does the insurer offer broader access? Some insurers run HMOs and PPOs in the same service area with different network sizes — a PPO from the same insurer often has a larger network than their HMO
For more on how network status affects what you actually pay, see our guide to out-of-network billing and the No Surprises Act.
What Happens When You Need Care and Aren't Sure of Your Plan
If you already have a plan and aren't sure whether it's an HMO, PPO, EPO, or POS, check:
- Your insurance card — the plan type is usually labeled on the card itself
- Your Summary of Benefits — the first page usually names the plan type
- Your insurer's member portal — log in and look for "plan type" in your account settings
If you've already gotten a bill from an out-of-network provider, you may have options — particularly if the provider was at an in-network facility (anesthesia, radiology, and assistant surgeons are common examples of OON providers at in-network hospitals). Our out-of-network guide covers how to identify and dispute those bills.
Also see: ClaimSage's Insurance Glossary for plain-English definitions of in-network, balance billing, allowed amount, prior authorization, and all other plan-related terms.