Cut through the noise, find the signal: Intelligence for serious healthcare leaders
Analysis updated November 9, 2026
The Medicare Shared Savings Program (MSSP), officially called the Shared Savings Program, is the largest and longest-running value-based care initiative in the Medicare fee-for-service (FFS) landscape. Authorized under the Affordable Care Act and operational since April 2012, it enables groups of doctors, hospitals, and other health care providers to organize as Accountable Care Organizations (ACOs) and take collective accountability for the quality, cost, and experience of care for an assigned Medicare FFS beneficiary population. The fundamental problem the program addresses is the misalignment between FFS volume-based payment incentives and the clinical and economic goals of high-quality, coordinated, cost-efficient care. When an ACO generates savings relative to its benchmark expenditure target while meeting quality standards, it becomes eligible to receive a share of those savings as performance payments. Two-sided risk tracks additionally expose ACOs to repayment obligations for excess spending, creating symmetric financial accountability.
The program's core value proposition is simultaneously organizational (creating structures for care coordination across provider types), financial (redirecting a portion of generated savings to participating providers), and clinical (establishing quality performance standards tied to shared savings eligibility). Unlike time-limited CMMI demonstration models, MSSP is a permanent Medicare program administered by CMS, which confers institutional durability and establishes it as the backbone of the federal government's alternative payment model (APM) strategy.
MSSP is the dominant vehicle through which Medicare FFS beneficiaries are attributed to value-based arrangements. The program's scale—with participation data released annually and ACO lists publicly available on Data.CMS.gov including ACO participants and Skilled Nursing Facility (SNF) affiliates—makes it the reference architecture for ACO market development. For health system executives, physician group administrators, and CFOs evaluating VBC strategy, MSSP represents the most accessible and policy-supported entry point into Medicare risk arrangements, with a structured glide path from one-sided shared savings toward two-sided performance-based risk.
The program is also the primary qualifying vehicle for Advanced APM status under the Quality Payment Program (QPP). ACO participants who meet Qualifying APM Participant (QP) thresholds—now subject to updated determinations at the TIN/NPI level under the CY 2027 PFS Final Rule—are exempt from MIPS participation and, beginning in 2026, receive a higher fee schedule update that grows by 0.5% annually relative to non-QPs. This QP pathway creates a compounding financial incentive for physician groups and practice networks to pursue MSSP participation as a component of their broader payment strategy.
The program's historical financial performance underscores its materiality: CMS reported that ACOs in MSSP saved Medicare more than $1.8 billion in 2022 and more than $1.6 billion in 2021. Performance Year (PY) 2024 financial and quality results were released on September 29, 2025, with full data available via the Performance Year Financial and Quality Results Public Use File (PUF) on Data.CMS.gov.
MSSP operates under the current Trump administration (second term, inaugurated January 20, 2025), with CMS Administrator Dr. Mehmet Oz and CMMI Director Abe Sutton overseeing CMS operations. The CY 2027 PFS Final Rule, finalized on November 4, 2026, carried a press release framing of "Shift from Sick Care to Healthcare and Curb Waste," signals that are consistent with the current administration's emphasis on prevention, wellness, reduced administrative burden, and elimination of low-value spending. MSSP's accountability structure—rewarding providers only when they demonstrably reduce costs while maintaining quality—aligns naturally with this administrative framing.
The rule's simultaneous emphasis on digital transformation (electronic prior authorization, interoperability, CEHRT requirements) and burden reduction (removal of ONC attestations, Security Risk Analysis measure, and the high-priority measure reporting requirement) reflects a regulatory philosophy of streamlining compliance while pushing forward technology modernization. For ACO operators, this translates to reduced reporting overhead in some domains offset by new electronic prior authorization obligations beginning CY 2028.
MSSP's regulatory evolution has several near-term market transformation implications for healthcare executives:
ACO Formation and Entry. Applications for a January 1, 2027 agreement start date are open, with Phase 1 submission having occurred June 9–23, 2026 and final dispositions issued December 8, 2026. The program's availability of Advance Investment Payments (AIP) for new, low-revenue ACOs and the new Prepaid Shared Savings (PSS) option for experienced two-sided ACOs expand the financial runway for both new entrants and established performers. These payment options signal CMS's intent to sustain and grow ACO participation across the experience spectrum.
Quality Reporting Modernization. The CY 2027 PFS Final Rule establishes a new Medicare eCQM collection type exclusively for MSSP ACOs reporting the APM Performance Pathway (APP) Plus quality measure set. It retroactively applies flat benchmarks to three key Medicare CQMs (Quality ID 001, 134, and 236) for the CY 2026 performance period, and extends this flat benchmarking prospectively for all Medicare CQMs. ACOs that choose to report Medicare eCQMs forfeit eligibility for the Complex Organization Adjustment and the eCQM/MIPS CQM reporting incentive, a material trade-off requiring deliberate organizational evaluation.
MIPS Trajectory. The sunset of traditional MIPS after the CY 2030 performance period—with MVPs becoming mandatory starting CY 2031 for non-APM clinicians—increases the relative attractiveness of MSSP as a pathway to APP/APP Plus reporting, which remains available beyond the traditional MIPS sunset. ACO operators with large employed or affiliated physician workforces should model the downstream QPP reporting implications of MSSP participation as MVP requirements harden over the next five performance years.
SNF Ecosystem Integration. The program's SNF 3-Day Rule Waiver (available to certain risk-track ACOs) and the public listing of SNF affiliates on Data.CMS.gov reflect CMS's intent to integrate post-acute care into ACO accountability structures. For health systems with SNF relationships, this waiver represents both a care coordination tool and a competitive differentiator in beneficiary management.
The Shared Savings Program is a voluntary program open to a defined set of eligible provider and supplier types. Eligible ACO participants include:
An ACO participant is defined as an entity identified by a Medicare-enrolled Taxpayer Identification Number (TIN) through which one or more ACO providers/suppliers bill Medicare. ACOs hold accountability for an assigned Medicare fee-for-service (FFS) beneficiary population, with assignment methodology selected during the application process (prospective or claims-based retrospective). Beneficiaries may select their primary clinician on MyMedicare.gov, and beneficiary alignment allows Nurse Practitioners, Physician Assistants, Certified Nurse Specialists, and certain other clinicians to anchor prospective assignment.
The program offers multiple participation tracks (BASIC and ENHANCED) with varying risk levels. The BASIC track operates as a glide path with increasing levels of risk designated as Levels A through E; Levels C, D, and E constitute two-sided risk. The ENHANCED track represents the highest level of risk and reward. ACOs selecting two-sided risk tracks (Levels C, D, or E of BASIC, or ENHANCED) must establish a repayment mechanism prior to their agreement period start.
Three significant payment mechanisms are available within MSSP:
1. Standard Shared Savings / Shared Losses. ACOs that generate savings against their benchmark receive a performance payment (shared savings). Two-sided risk ACOs that exceed their benchmark are obligated to repay a portion (shared losses).
2. Advance Investment Payments (AIP). Available to initial applicant ACOs (new entrants or re-entering ACOs), AIP provides upfront capital to build the infrastructure needed to succeed in MSSP. ACOs interested in AIP submit supplemental information and a spend plan through ACO-MS as part of their application. AIP eligibility final disposition is issued at the Phase 1 Final Disposition milestone (for the January 2027 cohort, this was October 20, 2026).
3. Prepaid Shared Savings (PSS). A newer payment option available to experienced two-sided risk ACOs with an established history of earning shared savings. PSS allows eligible ACOs to receive a portion of projected shared savings in advance. ACOs applying for PSS submit supplemental information and a spend plan through ACO-MS, and PSS eligibility final disposition is issued alongside AIP at October 20, 2026 for the January 2027 cohort. PSS requires its own repayment mechanism documentation, with specific escrow, surety bond, and letter of credit templates.
4. Beneficiary Incentive Program (BIP). ACOs in certain two-sided models may apply to establish a BIP, enabling them to offer financial incentives to beneficiaries for receiving qualifying primary care services. BIP application disposition is issued at the final application disposition milestone.
The following table documents the complete application timeline for the January 1, 2027 agreement start date:
| Milestone | Date / Window | Key Actions |
|---|---|---|
| Phase 1 Submission | June 9 – June 23, 2026 (noon ET) | ACO-MS registration; ACO Participant List with executed Participant Agreements; Banking Information; SNF 3-Day Rule Waiver application*; SNF Affiliate List*; Draft Repayment Mechanism*; Track selection; MSR/MLR selection*; Assignment methodology selection; Immediate beneficiary assignment estimates provided |
| Phase 1 RFI-1 | July 15 – August 5, 2026 (noon ET) | Update Banking Information; Update RM documentation*; Correct CMS-identified deficiencies; Final opportunity to add ACO participant and/or SNF affiliate TINs; Elect SNF 3-Day Rule Waiver*; Participation Options Report issued; Estimated RM amount provided |
| Phase 1 RFI-2 | August 27 – September 11, 2026 (noon ET) | Update Banking Information; Submit final RM documentation*; Final opportunity to upload executed agreements; Withdraw or delete ACO participants/SNF affiliates; Complete SNF 3-Day Rule Waiver application*; Participation Options Report and final RM amounts issued |
| Phase 1 Final Disposition | October 20, 2026 | ACO Participant List and SNF Affiliate List dispositions; Beneficiary Assignment Eligibility Phase 1; AIP Eligibility Final Disposition; PSS Eligibility Final Disposition |
| Phase 2 Submission | October 21 – October 30, 2026 (noon ET) | Governing body documentation and organizational chart; Governing body narrative*; AIP supplemental information and spend plan*; BIP application*; PSS supplemental information and spend plan* |
| Phase 2 RFI | November 12 – November 17, 2026 (noon ET) | Correct Phase 2 deficiencies; Modify Phase 2 responses; Phase 1 information cannot be modified |
| Final Application Dispositions | December 8, 2026 | Full application disposition; SNF 3-Day Rule Waiver*; BIP*; AIP*; PSS* dispositions issued |
| ACO Signing Event | December 9 – December 16, 2026 (noon ET) | Review, certify, and electronically sign program participation documents; Confirm organizational and contact information |
| Agreement Start Date | January 1, 2027 | New agreement period begins |
Applies only to certain ACOs
MSSP ACOs reporting under the APM Performance Pathway (APP) Plus are required to report a defined APP Plus quality measure set. The CY 2027 PFS Final Rule removes two previously included measures (Quality ID 305: Initiation and Engagement of Substance Use Disorder Treatment and Quality ID 493: Adult Immunization Status), resulting in an 8-measure set for the CY 2027 performance period and subsequent periods.
| Quality ID | Measure Title | Collection Types Available to MSSP ACOs |
|---|---|---|
| 001 | Diabetes: Glycemic Status Assessment Greater Than 9% | eCQMs; Medicare eCQMs*; Medicare CQMs*; Medicare Part B Claims (non-ACOs only); MIPS CQMs |
| 112 | Breast Cancer Screening | eCQMs; Medicare eCQMs*; Medicare CQMs*; Medicare Part B Claims (non-ACOs only); MIPS CQMs |
| 113 | Colorectal Cancer Screening | eCQMs; Medicare eCQMs*; Medicare CQMs*; Medicare Part B Claims (non-ACOs only); MIPS CQMs |
| 134 | Preventive Care and Screening: Screening for Depression and Follow-up Plan | eCQMs; Medicare eCQM*; Medicare CQMs*; Medicare Part B Claims (non-ACOs only); MIPS CQMs |
| 236 | Controlling High Blood Pressure | eCQMs; Medicare eCQMs*; Medicare CQMs*; Medicare Part B Claims (non-ACOs only); MIPS CQMs |
| 321 | CAHPS for MIPS | CAHPS for MIPS Survey (administered by CMS) |
| 479 | Hospital-Wide, 30-day, All-Cause Unplanned Readmission (HWR) Rate | Administrative Claims (calculated by CMS) |
| 484 | Clinician and Clinician Group Risk-standardized Hospital Admission Rates for Patients with Multiple Chronic Conditions | Administrative Claims (calculated by CMS) |
Available to Shared Savings Program ACOs only
Medicare eCQM Collection Type (New for CY 2027). CMS establishes a new collection type—Medicare Electronic Clinical Quality Measures for ACOs Participating in the Shared Savings Program (Medicare eCQMs)—exclusively for MSSP ACOs reporting the APP Plus quality measure set. The patient population is based on the ACO's assigned beneficiaries (consistent with Medicare CQMs). ACOs use existing eCQM specifications but report on assigned beneficiaries and use a different identifier to distinguish Medicare eCQM submissions. ACOs that report Medicare eCQMs are not eligible for the Complex Organization Adjustment or the eCQM/MIPS CQM reporting incentive.
MIPS CQMs Collection Type Extended. The MIPS CQMs collection type for MSSP ACOs remains available through the CY 2027 performance period and subsequent years, extended from its prior sunset. The MIPS CQM reporting incentive is similarly extended.
Medicare CQM Flat Benchmarking. All Medicare CQMs are scored using flat benchmarks beginning with the CY 2026 performance period. This policy is retroactively applied to Quality ID 001, 134, and 236 for CY 2026 and applies to all Medicare CQMs for CY 2027 and beyond. Medicare eCQMs are also scored using flat benchmarks for CY 2027 and subsequent periods. This eliminates the historical benchmark phase-in that previously applied after two years.
Revised Definition of "Beneficiary Eligible for Medicare CQMs." For CY 2027 and subsequent performance periods, the definition is revised to align with the population of beneficiaries assigned to the ACO, creating consistency across Medicare CQM and Medicare eCQM reporting populations.
CEHRT Modifications. The definition of Certified Electronic Health Record Technology (CEHRT) is modified at 42 CFR 414.1305 to align with the ONC HTI-5 Final Rule deregulatory policies, removing several ONC Health IT Certification Criteria from the definition: Family Health History (45 CFR 170.315(a)(12)), Patient Health Information Capture (45 CFR 170.315(e)(3)), Automated Numerator Recording (45 CFR 170.315(g)(1)), Automated Measure Calculation (45 CFR 170.315(g)(2)), and Clinical Quality Measures – Filter (45 CFR 170.315(c)(4)).
MSSP ACO participation qualifies as an Advanced APM, and clinicians meeting QP thresholds achieve Qualifying APM Participant (QP) status. Under the CY 2027 PFS Final Rule, QP and Partial QP determinations are now made at the TIN/NPI level rather than the NPI level, ensuring financial incentives flow only to TINs actively participating in an Advanced APM. Partial QP status is extended to all TIN/NPI combinations for NPIs achieving QP or Partial QP status through individual determinations.
For MSSP ACO clinicians who do not achieve QP status and remain subject to MIPS, the performance threshold remains at 75 points through the CY 2028 performance period / 2030 MIPS payment year. The maximum negative payment adjustment is -9% (applicable from the 2022 payment year forward per MACRA). The 2027 performance period feeds the 2029 MIPS payment year adjustments, with final scores below 18.75 points triggering the full -9% adjustment and scores between 18.76 and 74.99 points triggering a proportional negative adjustment.
Each participating ACO must maintain a compliance plan (certified but submitted only upon CMS request), execute an ACO Signing Event at the start and end of each performance year, maintain a current ACO Participant List with executed participant agreements, and submit banking information with supporting financial documentation as part of the application. Two-sided risk ACOs must maintain an active repayment mechanism in one of three forms: escrow agreement, letter of credit, or surety bond, with CMS-provided templates for each. Repayment mechanism amounts are determined during the application process, with estimated amounts provided at Phase 1 RFI-1 and final amounts at Phase 1 RFI-2.
Participating ACOs and their participants face potential information blocking disincentives under the HHS Information Blocking Disincentives Final Rule (effective June 24, 2024): a provider found by OIG to have committed information blocking may be ineligible to participate in the program for a period of at least one year, with CMS weighing relevant facts and circumstances before applying the disincentive.
The primary operational contact for participating ACOs is their assigned ACO Coordinator, with general operational and data inquiries directed to SharedSavingsProgram@cms.hhs.gov (including ACO ID and ACO name). Beneficiary inquiries are routed to 1-800-MEDICARE (1-800-633-4227).