A more thorough explanation:

A Health Maintenance Organization (HMO) is a type of medical insurance provider that offers low-cost health insurance plans. HMOs have a network of healthcare providers that they work with, and they only cover services provided by these providers. HMOs charge low or no deductibles and limited copays, making them an affordable option for many people.

For example, if you have an HMO plan and need to see a doctor, you will need to choose a doctor from the HMO's network. If you see a doctor outside of the network, you may have to pay for the services yourself. However, HMOs do cover emergency services, even if they are provided by an out-of-network provider.

HMOs are regulated by state and federal agencies to ensure that they provide quality healthcare services to their members. They must follow certain rules and regulations, such as not increasing payments or limiting coverage after an individual uses the insurance for basic health needs.