Which of the following is often not covered under health insurance plans?

Cosmetic surgery is often not covered under health insurance plans because it is typically classified as a procedure that is not medically necessary. Health insurance is primarily designed to cover treatments and services that are essential to maintaining health or treating illness and injuries. Preventive services, acute illness treatment, and emergency care are all critical medical services aimed at maintaining a person's health, managing illness, or addressing urgent medical needs, which is why they are generally included in health insurance coverage. Conversely, cosmetic surgery is usually sought for aesthetic reasons rather than medical ones, leading to its frequent exclusion from standard health insurance policies.