Many ACOs quietly lose ground on performance in Q1, long before quality scores or shared savings reports arrive. Attribution drift—when the population you are accountable for no longer matches how care is staffed, managed, and delivered—silently erodes care management efficiency, quality measure performance, and financial predictability. Left unmanaged, it turns January’s “quiet” reporting period into the moment when performance problems are locked in for the rest of the year. This article explains how attribution drift starts, the early warning signs leaders should watch, and how proactive attribution governance can protect both outcomes and teams by treating attribution as a core leadership responsibility, not a static CMS output.

The 2025 Medicare Shared Savings Program (MSSP) refresh brings critical updates for ACOs—including new risk tracks, quality benchmarks, and payment incentives. Whether you’re a new or experienced ACO participant, choosing between BASIC, ENHANCED, and ENHANCED+ tracks will shape your financial and operational success.

The CMS 2025 Final Rule introduces major updates for ACOs, including the shift to digital quality measures (dQMs) and the phase-out of the CMS Web Interface after 2024. With incentives for eCQMs/MIPS CQMs and alignment to the Universal Foundation of quality measures, ACOs will benefit from streamlined, digital reporting focused on value-based care.