Hello. Thank you for your question for CMS347v6: Statin Therapy for the Prevention and Treatment of Cardiovascular Disease. There is a denominator exception for patients meeting denominator criteria and having a statin allergy. As defined by the eCQI Resource Center ( https://ecqi.healthit.gov/sites/default/files/eCQM-Logic-and-Guidance-v7.pdf), a denominator exception is any condition that should remove a patient, procedure, or unit of measurement from the denominator of the performance rate only if the numerator criteria are not met. A denominator exception provides for the exercise of clinical judgment. The measured entity removes denominator exception cases from the denominator. However, the measured entity may still report the number of patients with valid exceptions. In your case, the patient in question who was prescribed a statin and subsequently found to have an allergy would obviously qualify for a denominator exception for future encounters where the patient was found to qualify for the measure denominator.