The largest primary care transformation model in Medicare history improved some utilization and still produced no net savings. This case covers why the null result is instructive.
Not every case study is a success story, and the honest ones matter most. Comprehensive Primary Care Plus (CPC+) was the largest primary care delivery model in Medicare’s history, and its independent evaluation is the clearest documentation of a hard truth: care can genuinely improve while the arithmetic of savings fails.
The model
| Element | Detail |
|---|---|
| Period | 2017 through 2021 for the main cohort |
| Scale | 2,905 practices in the regions that began in 2017, with commercial and Medicaid payers participating alongside Medicare |
| Mechanic | Monthly care management fees plus performance incentives layered on fee-for-service, in two tracks with different requirements |
| Evaluator | Mathematica, under contract to CMS |
The care management fees did what they were designed to do: practices reported them as the most useful support they received, funding care managers, behavioral health clinicians, and other staff, the team-based model described in Module 5.
What the evaluation found
- CPC+ reduced emergency department visits, acute inpatient hospitalizations, and acute inpatient spending relative to comparison practices.
- Those reductions were not large enough to offset the enhanced payments and spending growth in other categories (such as physician services), so the model produced no net Medicare savings in either track.
- Track 2, with greater funding and heavier care delivery requirements, showed no systematically better results than Track 1.
- Results were more favorable among independent practices and practices already in the Shared Savings Program, hinting that accountability for total cost, not payment enhancement alone, is where savings come from.
Worth remembering: a model can succeed at delivery transformation and fail at savings simultaneously. Which verdict matters depends on what you believe primary care investment is for.
What to take from it
CPC+ is the strongest evidence for a design lesson that echoes through Module 2: paying practices more, without accountability for total cost of care, buys real care improvements but not savings. Subsequent Medicare primary care models have paired investment with exactly that accountability.
Sources
Check your understanding
CPC+ reduced emergency department visits and acute hospitalizations. Why did it still fail to produce net Medicare savings?
The independent evaluation found real utilization effects, but after accounting for care management fees and higher spending in areas like physician services, total Medicare expenditures did not fall.