HMO, PPO, EPO, and HDHP: How the Four Main Plan Types Relate to Each Other

Why Four Plan Types Exist in the First Place

Most people enter open enrollment expecting to choose between an HMO and a PPO. In reality, the landscape includes four major structures — and each one emerged from a different attempt to balance two competing pressures: keeping premiums affordable and giving enrollees access to the care they need.

Here's the core tension: the more freedom a plan gives you to see any doctor, in any network, at any time, the more expensive it becomes for the insurer to administer — and the more of that cost gets passed to you through higher premiums. Plan designers have drawn that line in four different places, producing four distinct plan types.

It helps to think of them along two axes:

• Network restriction: Does the plan pay for out-of-network care at all?
• Referral requirement: Do you need a gatekeeper (your primary care physician) to send you to a specialist?

Once you understand where each plan falls on those two axes, the rest of the comparison becomes much more intuitive. Note that HDHP is slightly different — it describes a cost structure, not just a network type — and we'll address that distinction in detail below.

The Four Plan Types Defined

HMO — Health Maintenance Organization

An HMO assigns you to a primary care physician (PCP) who acts as the central coordinator of your healthcare. Want to see a cardiologist or dermatologist? Your PCP writes you a referral. Want to see a provider outside the plan's network? In most cases, you're paying the full bill out of pocket — the plan simply won't cover it (except in emergencies).

The tradeoff for accepting those constraints is usually the lowest premium of any plan type. HMOs also tend to have lower copays for in-network visits. If you have a regular doctor you trust and rarely need specialists, this structure can work extremely well.

PPO — Preferred Provider Organization

A PPO gives you a list of preferred (in-network) providers where you'll pay the lowest cost-sharing, but it doesn't lock you in. You can see out-of-network doctors and the plan still pays a portion — just less than it would for in-network care. Critically, you don't need a referral to book a specialist appointment directly.

That flexibility comes with a higher monthly premium. PPOs are the dominant plan type on employer-sponsored markets precisely because employees value the option to go out of network, even when they rarely exercise it.

EPO — Exclusive Provider Organization

An EPO is a hybrid: it applies strict network exclusivity (like an HMO) but removes the referral requirement (like a PPO). You can see any specialist in the network whenever you want, but step outside that network for non-emergency care and you're fully responsible for the cost.

EPOs are less widely offered than HMOs or PPOs, but they appear frequently on the ACA Marketplace. They're worth considering if you're comfortable staying within a network but dislike the extra step of getting referrals.

HDHP — High-Deductible Health Plan

An HDHP isn't defined by its network structure — it's defined by its deductible. The IRS sets the thresholds annually; in 2024, a plan qualifies as an HDHP if the deductible is at least $1,600 for an individual ($3,200 for a family). HDHPs can be structured as HMOs, PPOs, or EPOs underneath.

The key benefit of an HDHP is HSA eligibility. Only enrollees in a qualifying HDHP can open and contribute to a Health Savings Account, which lets you set aside pre-tax dollars to pay for qualified medical expenses. This is a significant tax advantage — and one of the most underused benefits in the employer benefits market. Learn more in our guide to HDHPs and HSAs.

How the Four Plans Stack Up Across Key Criteria

The table above lays out the structural differences clearly, but numbers only tell part of the story. Let's work through what each criterion actually means for your day-to-day experience.

Monthly Premiums

HMOs and EPOs are typically less expensive per month because insurers can negotiate steeper discounts with a defined network and predict costs more reliably. PPOs carry a premium for flexibility. HDHPs almost always have the lowest monthly premium of all — that's the trade you're making for a very high deductible.

Deductibles and Out-of-Pocket Costs

The deductible is the dollar amount you pay before insurance starts sharing costs. HMOs and EPOs often have lower deductibles than PPOs. HDHPs, by definition, have the highest deductibles — but this is offset if you're consistently contributing to an HSA and building a balance over time.

Referrals and Specialist Access

This is where daily friction enters the picture. HMOs require you to contact your PCP, get a referral generated, and in some cases wait for prior authorization before your specialist appointment is covered. EPOs and PPOs skip this step. If you manage a chronic condition and see specialists regularly, referral requirements translate directly into wasted time and occasional coverage disputes.

Out-of-Network Coverage

If you travel frequently, split time between cities, or have providers you're loyal to who aren't in-network, out-of-network coverage matters enormously. Only PPOs provide meaningful out-of-network benefits. HMOs and EPOs pay nothing for out-of-network non-emergency care. HDHPs can go either way depending on the underlying network structure.

The HDHP Distinction: Cost Structure vs. Network Structure

The most common point of confusion is treating HDHP as a fourth, parallel option to HMO, PPO, and EPO. It isn't — at least not cleanly. Think of it this way:

• HMO, PPO, and EPO describe how your plan's network and referral rules are organized.
• HDHP describes how your plan's cost-sharing is structured (specifically, a high deductible threshold).

An employer might offer you an HDHP/PPO — a PPO network with a high-deductible cost structure. Or an HDHP/HMO — a gatekeeper model with a high deductible. The HDHP label tells you about deductible size and HSA eligibility; the HMO/PPO/EPO label tells you about network access.

When insurers or employers present an HDHP as a standalone option next to an HMO or PPO, they're usually doing so for simplicity — and because the most common HDHP offering in the employer market is an HDHP with a PPO network. But it's worth asking: what's the underlying network type?

For a deeper look at how the HDHP cost structure compares to traditional HMO and PPO approaches, see our breakdown of HDHP with HSA vs. HMO vs. PPO.

Matching Plan Type to Real-Life Situations

Abstract comparisons only get you so far. Here's how each plan type tends to fit real enrollee profiles:

You're generally healthy and rarely use care

An HDHP makes strong financial sense here. You'll pay a low monthly premium, and since you're not generating large medical bills, you're unlikely to hit that high deductible. Fund an HSA aggressively and you're building a tax-advantaged medical reserve for the future.

You have a chronic condition or see specialists regularly

Look carefully at a PPO or an EPO. If your specialist is in-network and you don't mind staying there, an EPO gives you lower premiums without referral delays. If you need the flexibility to go out-of-network — say, a condition managed by a specialist at a university hospital that's not in most local networks — a PPO is worth the premium difference.

You're focused purely on minimizing monthly costs

HMOs typically win here, with EPOs as a close second. The key is verifying that the doctors you care about are actually in the plan's network before enrolling — network adequacy varies considerably by insurer and region.

You're enrolling your family, including children who may need specialist care

Family dynamics often push people toward PPOs, because the referral process can be especially cumbersome for pediatric subspecialties. However, a family HDHP with a robust HSA contribution from an employer can still compete on total cost, even with kids.

When it's time to make your final decision, our guide to choosing the right plan type at open enrollment walks through each scenario step by step.

One More Consideration: Dental Plan Types Follow the Same Logic

If you're sorting through medical plan types, it's worth knowing that dental insurance uses a nearly identical framework. Dental HMOs (sometimes called DHMOs or prepaid dental plans) assign you to a network dentist and require referrals for specialist care like orthodontics or oral surgery. Dental PPOs let you see any dentist but pay more for in-network visits. Indemnity dental plans — the oldest model — pay a set fee for any licensed dentist regardless of network.

The same cost-versus-flexibility tradeoff applies. Dental plan types explained offers a full comparison if you're evaluating dental coverage at the same time as your medical plan.

Similarly, if you're weighing all the variables that go into an HMO vs. PPO decision — from how often you travel to whether you manage a chronic condition — our comprehensive guide to everything that factors into HMO and PPO plan decisions covers every angle worth considering.

The Bottom Line: A Framework for Deciding

Rather than memorizing plan acronyms, remember the three questions that drive the decision:

1. How often do you use healthcare? Frequent users often benefit from lower deductibles and copays, which points toward HMO or PPO. Infrequent users can tolerate a high deductible in exchange for premium savings via an HDHP.
2. Do your preferred providers — especially specialists — sit inside the plan's network? If yes, an HMO or EPO works. If not, you need a PPO.
3. Can your cash flow absorb a large deductible in a bad year? If the answer is uncertain, think carefully before choosing an HDHP — unless you have or plan to build a meaningful HSA balance as a buffer.

No plan type is universally superior. The right choice is the one that matches your specific usage patterns, provider preferences, and financial situation — not the one with the most features on paper.