Bao B, Prasad AS, Beck FW, Fitzgerald JT, Snell D, Bao GW, et al
We explained our belief that this change would further encourage continued participation among high-cost ACOs that serve medically complex beneficiaries by eliminating the potential of a lower benchmark due to an overall negative regional adjustment, and may also encourage ACOs serving such populations that may have otherwise been discouraged from participating in the Shared Savings Program by the prospect of a lower benchmark to join (see 88 FR 79188, see also 88 FR 79494 and 79495)
*Correspondence: Ning Shen, [email protected] Disclaimer All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers

Common Z Codes for Vaccination Encounters Z20 - Contact with and (suspected) exposure to communicable diseases Z20.1 - Tuberculosis Z20.3 - Rabies Z20.4 - Rubella Z20.82 - Contact with and (suspected) exposure to other viral communicable diseases Z20.820 - Varicella Z20.828 - Contact with and (suspected) exposure to other viral communicable diseases Z20.81- * - Contact with and (suspected) exposure to other bacterial communicable diseases Z20.811 - Meningococcus Z20.9 - Contact with and (suspected) exposure to unspecified communicable diseases Z23 - Encounter for immunization Z51.89 - Encounter for other specified aftercare Z41.8 - Encounter for other procedures for purposes other than remedying health state Table 2: Immunization Not Carried Out and Underimmunization Status (Z28 Codes) Z28 - Immunization not carried out and underimmunization status Z28.0 - Immunization not carried out because of contraindication Z28.01 - Due to acute illness of patient Z28.02 - Due to chronic illness or condition of patient Z28.03 - Due to immunocompromised state of patient Z28.04 - Due to patient allergy to vaccine or component Z28.09 - Due to other contraindication Z28.1 - Immunization not carried out because of patient decision for reasons of belief or group pressure Z28.20 - Immunization not carried out because of patient decision for unspecified reason Z28.21 - Immunization not carried out because of patient refusal Z28.29 - Immunization not carried out because of patient decision for other reason Z28.81 - Immunization not carried out due to patient having had the disease Z28.82 - Immunization not carried out because of caregiver refusal (Excludes 1: caregiver refusal based on religious belief - Z28.1) Z28.83 - Immunization not carried out due to unavailability of vaccine Z28.89 - Immunization not carried out for other reason Current Procedural Terminology (CPT) and Medicare Coding for Vaccinations Vaccination Procedures A vaccination service includes two separate elements: Administration of the vaccine The vaccine product (drug) itself Administration may be performed by an obstetriciangynecologist or another qualified health care professional
