Health Maintenance Organization (HMO)

A health maintenance organization is a health plan that delivers care through a defined group of providers it employs or contracts with, in exchange for a fixed payment made in advance rather than a fee charged for each service. In the commercial market the term is a state licensing category: an insurer is licensed or organized under a state's law as an HMO, and the label on the plan follows from that. Federal regulation assumes the point rather than stating it: 42 C.F.R. 422.4(a)(1)(v)(C), a limb that applies "only for purposes of quality assurance requirements in § 422.152(e)" for a Medicare Advantage preferred provider organization, describes such a plan as one offered by an organization "not licensed or organized under State law as an HMO" — a phrase that means nothing unless the license comes from a state.

There is a federal definition, and it is worth knowing exactly what it covers, because it is routinely quoted as though it defined the market. 42 U.S.C. 300e(a) provides that "[f]or purposes of this subchapter, the term 'health maintenance organization' means a public or private entity which is organized under the laws of any State and which (1) provides basic and supplemental health services to its members in the manner prescribed by subsection (b), and (2) is organized and operated in the manner prescribed by subsection (c)." That subchapter is the Health Maintenance Organization Act of 1973, and the definition is doing a specific job: deciding which organizations are federally qualified. It is also, on its face, circular, since it defers the substance to the two subsections that follow. Those subsections are where the interesting material actually is.

Prepayment is the whole design, and everything else follows from it. 42 U.S.C. 300e(b)(1) requires that each member be provided basic health services for a payment that is "paid on a periodic basis without regard to the dates health services … are provided" and "fixed without regard to the frequency, extent, or kind of health service … actually furnished". Read that as an incentive statement. An organization paid the same amount whether a member comes in twice a year or twenty times has a direct financial interest in the member staying well, and an equally direct interest in limiting care that will not change an outcome. Both halves of the reputation the model carries come from that one sentence. The statute allows "additional nominal payments" for specific services, the ancestor of the modern copayment, but it forbids setting them at a level or in a manner that serves as a barrier to the delivery of health services.

The panel is closed, but not sealed. Section 300e(b)(3)(A) requires that at least 90 percent of the physician services provided as basic health services be delivered through staff of the organization, a medical group, an individual practice association, physicians under contract, or a combination of those. The remaining allowance covers services the organization determines are unusual or infrequently used, and services provided elsewhere because an emergency made it medically necessary. Section 300e(b)(4) is the counterpart obligation: services must be available and accessible within the service area with reasonable promptness, and 24 hours a day and seven days a week where medically necessary, and a member must be reimbursed for expenses in obtaining services elsewhere where they were "medically necessary and immediately required because of an unforeseen illness, injury, or condition." A closed network is therefore a bargain rather than a restriction on its own: the organization narrows where you may go, and in return owes you adequacy and access inside that area.

What the consumer-facing definition says, and what it does not. HealthCare.gov defines a health maintenance organization as "[a] type of health insurance plan that usually limits coverage to care from doctors who work for or contract with the HMO. It generally won't cover out-of-network care except in an emergency. An HMO may require you to live or work in its service area to be eligible for coverage. HMOs often provide integrated care and focus on prevention and wellness." Three things are in that definition: the closed panel, the emergency exception, and the service area. A referral from a primary care doctor is not. Many HMOs do require one, and requiring one is entirely consistent with the model, but it is a plan design decision rather than part of what makes a plan an HMO, and HealthCare.gov attaches the referral requirement to the point of service plan instead. The practical consequence is that "it is an HMO" does not tell you whether you need a referral. The plan documents do.

Where an HMO sits against the other three letters. A preferred provider organization pays something toward care from providers outside its network, which is the single structural difference and the reason its premium is generally higher. An exclusive provider organization is network-only, like an HMO, and the common gloss placing it "between an HMO and a PPO" gets the structure backwards; where an EPO typically differs is in letting a member go straight to a specialist. A point of service plan is the hybrid, combining an HMO-style primary care route with some coverage outside the network.

The employer-side provision most people have never heard of. The 1973 Act also reaches employers. 42 U.S.C. 300e-9 provides that an employer which offers its employees the option of membership in a qualified health maintenance organization must make a contribution for services offered by that organization "in an amount which does not financially discriminate against an employee who enrolls in such organization", and must run payroll deductions for it where the employee consents. The subsection defines non-discrimination by method rather than by amount: a contribution does not discriminate if the employer's way of determining contributions for all employees "is reasonable and is designed to assure employees a fair choice among health benefits plans." That is the rule behind the familiar situation where an employer's subsidy is stated as a flat dollar amount across every plan on the menu rather than as a percentage of each premium.

1. You choose the plan and, usually, a primary care physician from its panel during open enrollment.

2. The plan is paid a fixed amount per member per month, whether or not you use any care.

3. You use providers inside the network. Your cost is a copayment or coinsurance set by the plan.

4. Where the plan requires a referral or prior authorization, obtaining it is a condition of the claim being paid, not a formality.

5. Outside the network, the plan generally pays nothing, except in an emergency or where the organization could not supply the service.

6. Uncovered spending generally does not accumulate toward the deductible or the out-of-pocket maximum, so the annual ceiling protects you only against covered care.

A hypothetical, showing why the network line is different in an HMO. Delphine's HMO charges a $45 copayment for a specialist visit and requires a referral from her primary care physician. Her skin is bothering her, so she books directly with a dermatologist in the network and is seen. The practice bills $640. The plan denies the claim, because the referral condition was not met.

What she owes is now a question about the practice's contract rather than about her plan. Some network contracts hold the member harmless where the provider failed to obtain the referral, and some make an unauthorized service the member's own; where the latter applies she owes $640 rather than $45. And because the plan treated the service as not covered, the $640 generally does not count toward her deductible or toward her out-of-pocket maximum either, so the ceiling that would otherwise cap her year does not move. The referral would have cost her a primary care copayment and a week's delay.

Change one fact and it gets worse rather than better: if the dermatologist had been outside the network, an HMO would generally pay nothing at all regardless of referrals, because a plan that does not cover out-of-network care has no out-of-network cost-sharing tier to fall back to. That is the structural difference from a preferred provider organization, and it is worth pricing before choosing on premium.

Pros

• Premiums are generally the lowest of the common plan types, because a narrower panel gives the plan a stronger bargaining position on price.
• Cost sharing inside the network is usually simple and often a flat copayment, so the price of a visit is knowable in advance.
• The prepayment model gives the organization a direct interest in prevention and in coordinating care rather than in volume.
• Federal qualification standards require services to be available and accessible within the service area, including around the clock where medically necessary.
• A primary care physician who sees the whole picture is a real benefit for someone managing more than one condition, whatever the referral rules.

Cons

• Outside the network there is generally no coverage at all, rather than more expensive coverage, which is a difference in kind from a PPO.
• Uncovered spending generally does not count toward the deductible or the out-of-pocket maximum, so the annual ceiling does not protect against it.
• A referral or prior authorization requirement is a condition of payment, and missing it can convert a routine visit into a full billed charge.
• Eligibility can depend on living or working in the service area, which makes the plan a poor fit for a household split across regions or a student living away.
• The same incentive that funds prevention also funds utilization management, and the two are not separable.
• Provider panels change between plan years, so a plan that fits this year is worth re-checking at every open enrollment.