Health Maintenance Organization (HMO)
Updated for plan year 2026
In plain terms
A Health Maintenance Organization (HMO) is a plan built around a single local network and a primary care physician who coordinates your care. You generally need a referral from that doctor to see a specialist, and care outside the network isn't covered except in an emergency. In exchange for those rules, HMOs usually have the lowest premiums and may require you to live or work in the service area. They suit people who want lower costs and don't mind a coordinated, in-network approach.
A plain example
On your HMO, knee pain sends you first to your primary care doctor, who examines you and writes a referral to an in-network orthopedist. With the referral, your specialist visit is covered at your normal cost share. Skip that step and see the orthopedist directly, and the plan can deny the claim, leaving the bill to you.
Why it matters
An HMO trades flexibility for a lower price. If you're happy to route care through one doctor and stay in network, it's often the cheapest way to get covered. If you want to self-refer to specialists or keep out-of-network providers, its rules can feel like friction at the worst moment.
A common point of confusion
The referral requirement trips people up. On an HMO, seeing a specialist without your primary doctor's referral can mean the visit isn't covered at all, even if the specialist is inside the network. The referral, not just the network, is what unlocks coverage.