Medicare Shared Savings Program (MSSP)

Analysis updated November 9, 2026

Strategic questions for your team

Given that MSSP ACOs in two-sided risk tracks (BASIC Levels C, D, E or ENHANCED) must establish and maintain a repayment mechanism before the agreement period starts — with final repayment mechanism amounts determined by the Phase 1 RFI-2 deadline (September 11, 2026 for a January 1, 2027 start) — does our organization have sufficient capital reserves, credit capacity, or surety bond access to satisfy this requirement, and have we modeled our required repayment mechanism amount against projected shared losses under our chosen track?
Considering that MSSP ACOs pursuing Advance Investment Payments (AIP) or Prepaid Shared Savings (PSS) must submit supplemental information and spend plans during Phase 2 (October 21–30, 2026 for a January 1, 2027 start), and that PSS eligibility requires an established history of earning shared savings in two-sided risk models, does our ACO's performance history and financial infrastructure qualify us for either payment option, and what is our specific spend plan for deploying these funds to build care coordination infrastructure?
Given that the CY 2027 PFS Final Rule maintains a 75-point MIPS performance threshold through the CY 2028 performance period — with a maximum negative payment adjustment of -9% for scores between 0 and 18.75 points and a 2029 MIPS payment year impact — and that MSSP ACOs reporting the APP Plus quality measure set now have a finalized 8-measure set (reduced from 10 by removing Quality IDs 305 and 493), are our participating clinicians operationally ready to report all required APP Plus measures including CAHPS for MIPS, the two administrative claims measures calculated by CMS, and at least one of the available collection types (eCQMs, Medicare eCQMs, Medicare CQMs, or MIPS CQMs) for the remaining six measures?
With all Medicare CQMs now permanently scored using flat benchmarks for CY 2026 and all subsequent performance periods — including the retroactive application of flat benchmarks to Quality IDs 001, 134, and 236 for CY 2026 — and with the new Medicare eCQM collection type available for CY 2027 (but ineligible for the Complex Organization Adjustment or the eCQM/MIPS CQM reporting incentive), which collection type strategy maximizes our ACO's quality score and shared savings eligibility given our current EHR infrastructure and assigned beneficiary population?
Since the CY 2027 final rule modifies CEHRT requirements by removing five ONC Health IT Certification Criteria from the CEHRT definition (including Family Health History 45 CFR 170.315(a)(12), Patient Health Information Capture (e)(3), Automated Numerator Recording (g)(1), Automated Measure Calculation (g)(2), and Clinical Quality Measures Filter (c)(4)) and aligns with the HTI-5 Final Rule, and since the Electronic Prior Authorization measure becomes required starting CY 2028 while the new Electronic Prior Authorization for Prescription Drugs measure also becomes required in CY 2028, does our ACO's current CEHRT meet the updated definition and do we have a 12-to-24-month technology roadmap to achieve full electronic prior authorization capability for both medical items/services and prescription drugs before the 2028 performance period?
Given the MSSP application timeline for a January 1, 2027 agreement start date — with Phase 1 Submission open only June 9–23, 2026, Phase 1 Final Disposition issued October 20, 2026, Phase 2 Submission open October 21–30, 2026, Final Application Dispositions on December 8, 2026, and ACO Signing Event December 9–16, 2026 — have we assigned dedicated staff to manage each application phase, secured all required ACO Participant Agreements and ACO Participant List submissions, and established a governance structure with an organizational chart and governing body narrative ready for Phase 2 submission?
Since traditional MIPS will sunset after the CY 2030 performance period and MVPs will become the only MIPS reporting option for non-MIPS APM clinicians beginning in the CY 2031 performance period — with 30 MVPs now available for 2027 including three new ones (Diabetic Disease, Hypertension, and Hospitalist) and all 27 existing MVPs modified to include MIPS core measure selections — and since reporting a MIPS core measure is now required (with a 0-out-of-10-point penalty for non-compliance absent a small practice exemption or attestation of non-applicability), which MVP or combination of MVPs best aligns with our ACO's specialty mix, and have we identified applicable MIPS core measures from the 77-measure inventory for each major clinician cohort within our network?
Given that QP and Partial QP determinations will now be applied at the TIN/NPI level rather than the NPI level — ensuring financial incentives flow only to TINs actively participating in an Advanced APM — and that QPs receive a higher fee schedule update growing by 0.5% annually relative to non-QPs beginning in 2026, have we audited which of our participating clinicians' TIN/NPI combinations will achieve QP or Partial QP status under the updated thresholds finalized in response to the Consolidated Appropriations Act, 2026, and have we modeled the net financial impact of QP status versus MIPS participation for each distinct billing TIN in our ACO?
Given that ACOs or their participants found to have committed information blocking — as defined under Section 4004 of the 21st Century Cures Act and enforceable through the June 2024 HHS final rule — may be ineligible to participate in MSSP for at least one year, have we conducted a comprehensive information blocking compliance audit across all ACO participants and ACO providers/suppliers, and do we have documented policies and corrective action procedures that satisfy CMS's requirement for a compliance plan that must be certified and available for submission upon request?

Traps and concerns

Benchmark Erosion from SAHS Billing Anomalies
MSSP ACOs face payment/reconciliation risk from Significant, Anomalous, and Highly Suspect (SAHS) billing activity that distorts financial benchmarks outside the ACO's control. CMS demonstrated this vulnerability in a September 2024 final rule (CMS-1799-F) that had to retroactively mitigate the impact of anomalous intermittent urinary catheter billing on PY 2023 ACO financial performance, as well as on benchmarks for ACOs starting agreement periods in 2024, 2025, and 2026. ACOs cannot predict or prevent third-party billing anomalies from corrupting their historical benchmarks, potentially suppressing shared savings calculations or inflating shared loss determinations by millions of dollars across a three-year agreement period before CMS intervenes with a corrective rule.
Repayment Mechanism Miscalibration at Track Entry
ACOs entering two-sided risk models (BASIC track Levels C, D, or E, or ENHANCED track) must establish an adequate repayment mechanism—escrow, letter of credit, or surety bond—before their agreement period begins. The repayment mechanism amount is calculated by CMS and communicated during the Phase 1 RFI-2 window (closing September 11, 2026 for January 1, 2027 start dates), with final amounts binding at that point. If an ACO's patient population shifts materially between application and performance year start, or if leadership underestimates the required amount, the ACO risks either being deemed non-compliant and disqualified from two-sided participation, or being locked into an overcapitalized repayment mechanism that constrains working capital. ACOs must monitor the ACO-MS system precisely within the narrow RFI-2 window to course-correct.
Medicare eCQM Submission Disqualifies Incentive Payments
Beginning with the CY 2027 performance period, CMS is establishing a new Medicare eCQM collection type exclusively for Shared Savings Program ACOs reporting the APP Plus quality measure set. However, ACOs that elect to report Medicare eCQMs are explicitly ineligible for the Complex Organization Adjustment and the eCQM/MIPS CQM reporting incentive under the Shared Savings Program. ACOs that migrate to the new Medicare eCQM pathway to reduce operational burden or align with digital transformation priorities without recognizing this financial trade-off will forfeit incentive payments they would have retained under the MIPS CQMs or standard eCQMs collection types. This regulatory compliance trap is embedded in a seemingly administrative collection-type election decision.
Retroactive Flat Benchmark Application Distorts Quality Scoring Strategy
CMS finalized in the CY 2027 PFS Final Rule (November 4, 2026) that all Medicare CQMs will be scored using flat benchmarks for the CY 2026 performance period and subsequent periods—including retroactive application to three measures already reported in CY 2026: Diabetes Glycemic Status Assessment (Quality ID: 001), Screening for Depression and Follow-up Plan (Quality ID: 134), and Controlling High Blood Pressure (Quality ID: 236). ACOs that built their CY 2026 quality improvement strategies and resource allocation decisions around anticipated historical benchmarks for these three measures will find their quality scoring recalculated retroactively under flat benchmarks, potentially shifting their quality performance category scores and altering shared savings eligibility or payment amounts after the performance period has already closed.
MIPS Core Measure Workflow Gap Triggers Zero-Point Scoring
Beginning with the CY 2027 performance period, MSSP ACOs reporting under traditional MIPS or MVPs must report at least one MIPS core measure (drawn from a 78-measure pool, finalized in Appendix H of the CY 2027 PFS Final Rule) as one of their required quality measures. If an ACO fails to report a MIPS core measure and does not submit a timely attestation that no applicable core measure exists, it receives 0 out of 10 points for one of its required quality measures—a scoring penalty that cannot be corrected post-submission. ACOs with narrow specialty compositions or limited EHR infrastructure for new measure specifications face operational risk from this hard scoring floor, particularly given that historical benchmarks for 2027 core measures will not be available until late January 2027, compressing implementation timelines.
ACO Participant List Freeze Creates Mid-Cycle Network Risk
The MSSP application timeline creates an irrevocable lock on the ACO Participant List at Phase 1 RFI-2 (closing September 11, 2026 for the January 1, 2027 agreement start). After that deadline, ACOs cannot add or edit ACO participant or SNF affiliate TINs, even through Phase 2 or the Signing Event (December 9–16, 2026). If a key participant group merges, is acquired, changes ownership, or exits between September 2026 and the agreement start date, the ACO cannot update its network composition. This creates a structural mismatch between the ACO's contracted provider network and its CMS-approved participant list, risking beneficiary misassignment, diluted care coordination reach, and potential compliance deficiencies if participant agreements are no longer executed as submitted.
Information Blocking Violation Triggers Multi-Year Program Exclusion
Under the HHS Information Blocking Disincentives Final Rule (June 24, 2024, implementing 21st Century Cures Act Section 4004), any ACO, ACO participant, or ACO provider/supplier found by the HHS Office of Inspector General to have committed information blocking may be rendered ineligible to participate in the Shared Savings Program for a period of at least one year. CMS retains discretion to consider mitigating factors (time since conduct, remediation efforts, other disincentives applied), but there is no guaranteed safe harbor. For ACOs with large, decentralized participant networks—including hospitals, physician groups, and SNF affiliates—a single participant's EHR configuration decision that restricts data exchange could trigger an OIG referral and program exclusion that disrupts the entire ACO's shared savings track record, benchmark continuity, and advanced investment payment or prepaid shared savings obligations.