occurrence policy /əkur″əns/ [L, occurere, to run, politica, pertaining to the state] , a professional liability insurance policy that covers the holder during the period an alleged act of malpractice occurred. Occurrence policies are said to have a “long tail” because the statute of limitations on malpractice allegations is unlimited. Thus an individual could be sued years after an event took place. If the individual held an occurrence type of malpractice policy, there would be protection under that policy. Under a claims-made policy there would not be protection unless the policy was current.