A more thorough explanation:

Health maintenance organizations (HMO) are a type of medical insurance provider that offer low-cost insurance plans in exchange for limited coverage. HMOs only cover medical services provided by doctors within their network, which helps keep costs low. They also typically charge low or no deductibles and limited copays.

For example, if you have an HMO plan and need to see a doctor, you would need to choose a doctor within the HMO's network. If you choose to see a doctor outside of the network, you may have to pay for the services out of pocket.

HMOs achieve their low prices by hiring doctors directly or through contracts to provide coverage for their patients. They must follow federal and state regulations, such as not increasing payments or limiting coverage after an individual uses the insurance for basic health needs.

Overall, HMOs are a popular choice for individuals who want low-cost insurance and are willing to limit their choice of doctors to those within the HMO's network.