As a general proposition, insurers and plans cannot cancel an individual's coverage under a policy or plan arbitrarily. In addition, federal and state laws prohibit discrimination based upon race, national origin, gender or age. Some states have been proactive, as well, in the area of discrimination involving particular medical conditions or traits. For instance, some states prohibit insurers and plans from denying health care coverage to, or canceling health care coverage of, persons with mental dementia (such as Alzheimer's disease) or human immunosuppressive virus (HIV) or mental illness.

Health care insurance policies or plans can be canceled (rescinded) if there is a material omissions or misrepresentations made by the insured or member in the application for coverage. Recession, in general, works as follows: when you apply for insurance and sign an application, you answer questions and provide information about the medical history of anyone who will be covered under the policy or plan. In doing so, you must reveal any serious medical condition or treatment that might reasonably affect the decision by the insurer or plan to undertake the risk associated with providing the coverage.

Even if the policy or plan is issued and premiums are paid, the insurer or plan can cancel or rescind the policy later if they discover that the policyholder or insured did not disclose in the application significant medical history. The result is that the insurer or plan does not pay for the care that was rendered, the policy is canceled and the premiums that were paid on the policy are returned to the policyholder less a reasonable cost of insurance associated with the period of time during which the policy was in force.

A limited form of cancellation can occur involving reduction or elimination of benefits. Other than a requirement of reasonable notice, insurers and plans may reduce or eliminate benefits, unless the contract or plan prohibits it or limits it. In some states there is a major exception known as "vesting," which means that if the insured or member already has a claim or has received benefits for a particular injury or illness, they may continue to receive the benefit even if it is otherwise canceled.