Medical necessity

Medical necessity is a United States legal doctrine, related to activities which may be justified as reasonable, necessary, and/or appropriate, based on evidence-based clinical standards of care. Other countries may have medical doctrines or legal rules covering broadly similar grounds. The term clinical medical necessity is also used. In contrast, unnecessary health care lacks such justification.

Medicare pays for medical items and services that are "reasonable and necessary" for a variety of purposes. By statute, Medicare may only pay for items and services that are "reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member", unless there is another statutory authorization for payment.

Medicare has a number of policies, including National coverage determinations (NCDs) and Local Coverage Determinations (LCDs), formerly known as Local Medical Review Policies (LMRP), that describe coverage criteria.

In a small number of cases, Medicare may determine if a method of treating a patient should be covered on a case-by-case basis. Even if a service is medically determined to be "reasonable and necessary," coverage may be limited if the service is provided more frequently than allowed under Medicare coverage policies.

The use of cannabis (also known as marijuana) for medical purposes is a notable 'medical necessity' case. Cannabis is a plant whose active ingredients are widely reported by sufferers to be effective in pain control for various conditions, usually neuropathic in nature, where common painkillers have not had great benefit; however as a Schedule I drug under the Controlled Substance Act, it is illegal and is targeted by government, police, and anti-drug campaigners: in some states, possession is decriminalized for even non-medical purposes, wherein other states possession is a felony offense. In this case the doctrine of medical necessity would be used by a patient who believed marijuana was beneficial to them if charged with use or growing/production of illegal controlled substance relating to marijuana.

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