Which of the following is a common type of health insurance plan?

A Health Maintenance Organization (HMO) is a common type of health insurance plan designed to provide comprehensive health services for a set fee. Members of an HMO generally choose a primary care physician who manages their healthcare and provides referrals to specialists when necessary. This structure encourages coordinated care and typically emphasizes preventive services, which can help reduce overall healthcare costs. HMOs often require members to use a network of doctors and hospitals within the plan to receive the highest level of benefits, making them a popular choice for individuals seeking affordable and managed health care options.

In contrast, the other options listed pertain to financial or retirement planning rather than health insurance. A 401(k) is a retirement savings plan, a certificate of deposit (CD) is a type of savings account with a fixed interest rate and maturity date, and an individual retirement account (IRA) is another form of savings account designed for retirement. These options do not offer health insurance coverage or related services, thus illustrating the unique role that HMOs play in the health insurance landscape.