An Impairment Rating is a medical assessment of a claimant’s injury represented by a percentage value. A physician may assign an impairment rating to the body as a whole or to a specific body part depending on the state’s regulations. The rating may then be used to calculate the workers’ comp benefits owed to a claimant. Impairment ratings are important in determining permanent partial disability benefits. An impairment rating evaluation can be performed in conjunction with an IME exam or as a separate evaluation.