(a) For performance years 2012 through 2015, CMS employs the following step-wise methodology to assign Medicare beneficiaries to an ACO after identifying all patients that had at least one primary care service with a physician who is an ACO professional of that ACO:
(1)(i) Identify all primary care services rendered by primary care physicians during one of the following:
(i) Identify all primary care services rendered by primary care physicians during one of the following:
(A) The most recent 12 months (for purposes of preliminary prospective assignment and quarterly updates to the preliminary prospective assignment).
(B) The performance year (for purposes of final assignment).
(ii) The beneficiary is assigned to an ACO if the allowed charges for primary care services furnished to the beneficiary by all the primary care physicians who are ACO professionals in the ACO are greater than the allowed charges for primary care services furnished by primary care physicians who are--
(A) ACO professionals in any other ACO; and
(B) Not affiliated with any ACO and identified by a Medicare-enrolled TIN.
(2) The second step considers the remainder of the beneficiaries who have received at least one primary care service from an ACO physician, but who have not had a primary care service rendered by any primary care physician, either inside or outside the ACO. The beneficiary will be assigned to an ACO if the allowed charges for primary care services furnished to the beneficiary by all ACO professionals in the ACO are greater than the allowed charges for primary care services furnished by--
(i) All ACO professionals in any other ACO; and
(ii) Other physicians, nurse practitioners, physician assistants, clinical nurse specialists who are unaffiliated with an ACO and are identified by a Medicare-enrolled TIN.
(b) For performance year 2016 and subsequent performance years, CMS employs the following step-wise methodology to assign Medicare fee-for-service beneficiaries to an ACO:
(1) Identify all beneficiaries that had at least one primary care service with a physician who is an ACO professional in the ACO and who is a primary care physician as defined under Sec. 425.20 or who has one of the primary specialty designations included in paragraph (c) of this section.
(2) Identify all primary care services furnished to beneficiaries identified in paragraph (b)(1) of this section by ACO professionals of that ACO who are primary care physicians as defined under Sec. 425.20, non-physician ACO professionals, and physicians with specialty designations included in paragraph (c) of this section during the applicable assignment window.
(3) Under the first step, a beneficiary identified in paragraph (b)(1) of this section is assigned to an ACO if the allowed charges for primary care services furnished to the beneficiary by primary care physicians who are ACO professionals and non-physician ACO professionals in the ACO are greater than the allowed charges for primary care services furnished by primary care physicians, nurse practitioners, physician assistants, and clinical nurse specialists who are--
(i) ACO professionals in any other ACO; or
(ii) Not affiliated with any ACO and identified by a Medicare-enrolled billing TIN.
(4) The second step considers the remainder of the beneficiaries identified in paragraph (b)(1) of this section who have not had a primary care service rendered by any primary care physician, nurse practitioner, physician assistant, or clinical nurse specialist, either inside the ACO or outside the ACO. The beneficiary will be assigned to an ACO if the allowed charges for primary care services furnished to the beneficiary by physicians who are ACO professionals with specialty designations as specified in paragraph (c) of this section are greater than the allowed charges for primary care services furnished by physicians with specialty designations as specified in paragraph (c) of this section--
(i) Who are ACO professionals in any other ACO; or
(ii) Who are unaffiliated with an ACO and are identified by a Medicare-enrolled billing TIN.
(c) ACO professionals considered in the second step of the assignment methodology in paragraph (b)(4) of this section include physicians who have one of the following primary specialty designations:
(1) Cardiology.
(2) Osteopathic manipulative medicine.
(3) Neurology.
(4) Obstetrics/gynecology.
(5) Sports medicine.
(6) Physical medicine and rehabilitation.
(7) Psychiatry.
(8) Geriatric psychiatry.
(9) Pulmonary disease.
(10) Nephrology.
(11) Endocrinology.
(12) Multispecialty clinic or group practice.
(13) Addiction medicine.
(14) Hematology.
(15) Hematology/oncology.
(16) Preventive medicine.
(17) Neuropsychiatry.
(18) Medical oncology.
(19) Gynecology/oncology. [76 FR 67973, Nov. 2, 2011, as amended at 80 FR 32841, June 9, 2015]