A health insurance company covers the cost of the benefits that are mentioned in their health insurance policies. These may include both tests and treatments. Benefits offered by a health insurance policy that are covered by the insurance company are known as “covered services”. The policyholder is responsible for paying for medical care that is not covered by insurance company.

Some health insurance companies provide cover for specific critical illnesses, accidents, disability, non-urgent healthcare services, orthopedic surgery, hospitalization, and loss of limbs. But each plan is different: the health insurance coverage basically depends upon the particular plan purchased. Most health insurances in the U.S are bound by law to cover mandated benefits like treatment for diabetes and screening for prostate cancer.

There has been a gradual trend of seeking policies that offer surgical coverage instead of coverage for ailments treated by the family doctor. It is not uncommon for a health insurance policyholder to find that the medical service that he most requires is not covered by his policy. It is helpful if a policyholder's family doctor is conversant with what the policy covers so that if possible he can prescribe medical treatment that is covered in the policy.

Health insurances may also cover disability and provide the policyholder with an income, which is a percentage of his actual income. This is applicable if the disablement occurs due to a mishap or an illness and renders the policy holder incapable of work. Ideally, the policy should provide coverage at least until the age of 65.

The important fact to remember is that every health insurance program is unique, and offers different coverage. You shouldn't ever assume you have a particular coverage, but instead should make sure to read the fine print of the policy. Finally, to be safe, only seek insurance from a reputable company.