For a generation, states have taxed hospitals, nursing homes and health plans and used the proceeds to draw down federal Medicaid dollars. On October 1, 2026, the federal ceiling on that practice froze. California, which relies heavily on a tax on managed-care plans, faces a second and separate deadline on December 31, 2026. Both deadlines bear directly on what Medi-Cal can pay physicians.
How provider taxes work
A state levies a tax on a class of health-care providers or health plans and uses the revenue as part of its own share of Medicaid spending, which the federal government then matches. Federal law forbids "hold harmless" arrangements that guarantee taxed providers their money back. Since 1999, CMS has treated a tax at or below 6 percent of the taxed class's net patient revenue as falling within a safe harbor from the indirect form of that prohibition (Holland & Knight).
What changed on October 1, 2026
Primary recordSection 71115 of Public Law 119-21 amended the Social Security Act's provider-tax provision to set new indirect hold-harmless thresholds effective October 1, 2026 (CMS guidance letter, November 14, 2025). In practice, the thresholds are frozen at the level of taxes both enacted and imposed as of July 4, 2025, so a state cannot impose a new or increased provider tax (State Health and Value Strategies). In states that expanded Medicaid, including California, the threshold then phases down beginning October 1, 2027 (Federal Register), reaching 3.5 percent by 2032 (LeadingAge).
What CMS has proposed but not finalized
CMS's proposed rule, published July 23, 2026, would replace the uniform 6 percent threshold with state-specific and class-specific thresholds based on taxes in place on July 4, 2025, with a threshold of zero for any class that had no qualifying tax that day. It would apply "interim" thresholds from October 1, 2026, to September 30, 2028, while CMS reviews state data; end the alternative "75/75" compliance test after September 30, 2026; add "services of health insurers" as a new class of permissible tax; and require quarterly state reporting starting October 1, 2026 (Federal Register; Becker's Payer).
CMS's Office of the Actuary estimates the proposed rule would cut federal Medicaid spending by about $246 billion from 2026 through 2035, more than the Congressional Budget Office's $183 billion estimate for the statutory provision alone (Avalere Health). That figure belongs to the proposal. It is not the measured effect of the October 1 statute, and the rule may change before it is final.
California: two clocks, not one
The MCO tax clock: December 31, 2026. California's tax on managed-care organizations is authorized through December 31, 2026. In February 2026, CMS finalized a separate rule on health-care-related taxes that leaves California's tax intact through that date, after which the same structure will no longer be federally approvable (DHCS, Medi-Cal financing).
The Proposition 35 constraint. Proposition 35, approved by voters in November 2024, made the MCO tax permanent subject to federal approval, dedicated its revenue to specified Medi-Cal purposes, and requires the state to seek approval of a substantially similar tax (DHCS). The 2026 Budget Act assumes a renewed, federally conforming MCO tax beginning January 1, 2027, and reflects MCO tax revenue of $2.5 billion in 2026–27, down from $4.5 billion in 2025–26 (DHCS budget highlights; May Revision summary). The May Revision describes the 2027 tax as having two components: one substantially similar to the current tax under Proposition 35, and one dissimilar component authorized by the Legislature.
The provider-tax clock: October 1, 2026. California's other provider taxes are now held at their July 4, 2025 levels and, because California expanded Medicaid, face the phase-down beginning October 1, 2027. State-directed payments are on a third track: CMS issued revised preliminary guidance in February 2026 and a proposed rule in May 2026 (DHCS).
What is settled and what is not
| Settled | Not settled |
|---|---|
| The statutory threshold change took effect October 1, 2026 | Whether and when CMS finalizes its proposed rule, and in what form |
| California's current MCO tax ends December 31, 2026, in its present form | Whether CMS approves California's 2027 MCO tax |
| Proposition 35 requires the state to seek a substantially similar tax | How Proposition 35's rate increases are funded if the renewed tax yields less |
| New or increased provider taxes are effectively barred | California's interim class-specific thresholds |
| The expansion-state phase-down begins October 1, 2027 | Final federal limits on state-directed payments |
Why physicians should care
AnalysisSince 2024, MCO tax revenue has paid for targeted Medi-Cal rate increases for primary care, specialty care and other services, and Proposition 35 earmarked future revenue for the same purposes. A smaller or restructured tax from January 2027 therefore bears directly on what Medi-Cal pays physicians. The exposure is greatest where Medi-Cal covers a large share of patients, which describes much of the San Joaquin Valley.
What to watch
- CMS's final rule on provider-tax thresholds.
- CMS's decision on California's 2027 MCO tax.
- Meetings of the Proposition 35 Stakeholder Advisory Committee.
- The new Governor's first budget proposal in January 2027.