CMS = Centers for Medicare and Medicaid Services; CPC+ = Comprehensive Primary Care Plus; ED = emergency department; FFS = fee for service; HCC = hierarchical condition category; IQR = interquartile range.

Note: Primary care practices include all practices with ≥ 1 practitioner (defined as a physician, nurse practitioner, or physician assistant) with a specialty of primary care (defined as family practice, general practice, geriatrics, or internal medicine). The 2018 starters represent 11% of all practices, 7% of applicants, and 5% of participants.

Sources: Mathematica’s analysis of data on the number, characteristics, and service use and spending of attributed Medicare beneficiaries based on Medicare Enrollment Database and claims data.

↵a Table includes 16,883 of the 19,809 primary care practices in the 2017 and 2018 regions because we excluded 2,926 practices (15%) that had no attributed Medicare FFS beneficiaries in the baseline year.

↵b A total of 4,599 practices applied for CPC+. The number of applicants in this table (4,346) is fewer because some applicants could not be identified in the SK&A data, and some applicants had no attributed Medicare FFS beneficiaries at baseline.

↵c The baseline year is 2016 for the 2017 starters and 2017 for the 2018 starters.

↵d Calculated as the percentage of beneficiaries attributed to a practice in the baseline year who were dually eligible for Medicare and Medicaid in the quarter before the start of the baseline year.

↵e The HCC score is based on beneficiaries’ diagnoses in 2015 (for 2017 starters) or 2016 (for 2018 starters).

↵f The lookback periods for the chronic conditions are 3 years before the baseline year for Alzheimer and related dementia, 1 year before the baseline year for cancer and chronic obstructive pulmonary disease, and 2 years before the baseline year for chronic kidney disease, congestive heart failure, and diabetes.

↵g We deflated the 2017 (baseline) mean and median per beneficiary per month expenditures for the practices in the 2018 CPC+ regions by the 0.9% Medicare inflation rate (CMS Office of the Actuary, personal communication, May 6, 2019).

↵h For the calculation of the weighted (mean/median) monthly Medicare expenditures per beneficiary, the practice-level expenditure variable (mean/median) is weighted by the number of beneficiaries attributed to the practice, so that practices with more attributed beneficiaries get a greater weight. The means and medians for all of the other characteristics in the table are unweighted, meaning that each practice is treated equally, regardless of its size.

↵i This measure was calculated for beneficiaries attributed in the first quarter of the baseline year.