Physicians who perform impairment evaluations should base their ratings on the objective condition of the patient, along with credible subjective findings. In making interpretations and judgments, examiners have obligations that are distinct from the duty of care as a treating physician. An experienced attending clinician, for example, may be unfamiliar with the correct process of rating impairment or may not feel unbiased in performing the rating. If significant new diagnoses are discovered, the physician has a medical obligation to inform the requesting party and individual about the condition and to recommend or refer for further medical assessment. When the physician is uncertain about which method to use to calculate an impairment rating or if more than one method can accurately be used, the physician should calculate the impairment rating using different alternatives and choose the method or combination of methods that best represents the functional impairment of the individual. The attending physician often is the person most knowledgeable about the injured employee and is encouraged to render the final impairment rating, when possible. Depending on the jurisdiction, examiners may be required to comply with specific constraints and duties regarding the rating. Examiners should not question an individual's integrity but can appropriately comment on the person's credibility.