A type of health insurance plan that usually limits coverage to care from providers who work for or contract with the HMO. HMOs require a primary care physician (PCP) as well as a referral from a PCP to access care from a specialist. These plans generally do not cover healthcare services accessed from out-of-network providers 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.