On July 24, 2025, the OIG released reports evaluating the prevalence of patient harm in hospitals and the extent to which hospitals detect and report such events. These evaluations follow up on OIG’s 2022 report and provide additional detail on internal patient harm incident tracking and external reporting practices among hospitals serving Medicare beneficiaries.
Background
As a Condition for Participation in the Medicare program, hospitals must establish and maintain a Quality Assessment and Performance Improvement (QAPI) program. To meet QAPI requirements under 42 CFR § 482.21, hospitals must “track medical errors and adverse patient events, analyze their causes, and implement preventive actions and mechanisms that include feedback and learning throughout the hospital.” Under OIG’s definition of “patient harm,” patient harm includes “as any undesirable clinical outcome. . . that was the result of medical care or that occurred in a health care setting” and not a result of the underlying disease.
May 2022 Report: A Quarter of Medicare Patients Experienced Harm in October 2018
In its previous May 2022 report (OEI-06-18-00400), the OIG found that 25% of Medicare patients experienced harm during acute-care hospital stays in October 2018. Of these, 12% experienced adverse events causing longer stays, life-sustaining interventions, or permanent harm, and 13% experienced temporary harm requiring intervention. Physician reviewers determined that 43% of all harm events were preventable, often due to substandard care or inadequate monitoring.
Only a small fraction of the identified harm events appeared on CMS’s hospital-acquired conditions (HAC) lists, which are used in payment and quality incentive programs: 5% were listed in the HAC Reduction Program and 2% were listed under the Deficit Reduction Act’s requirements.
July 2025 Report: Hospitals Did Not Capture Half of Patient Harm Events
In a follow-up July 2025 report (OEI-06-18-00401), OIG found that hospitals failed to capture in their incident reporting systems 49% of harm events that occurred among hospitalized Medicare patients. For this report, the OIG assessed whether hospitals had captured the harm events identified in the 2022 study described above through internal systems and evaluated whether hospitals externally reported captured events as required by CMS and state authorities. Specifically, OIG traced the 299 harm events identified in the previous 2022 report and administered a survey to the hospitals at which the harm events occurred. OIG received responses for 266 of the 299 harm events. In total, hospitals captured only 94 of 266 harm events, and a much smaller subset was reported externally. Of the 15 events identified as reportable under federal or state requirements, hospitals reported only 5.
In many cases, staff did not recognize the events as reportable or did not consider reporting to be standard practice. For the harm events that were captured, hospitals rarely conducted investigations or implemented corrective actions to improve patient safety and reduce the risk of future harm.
The OIG recommended that CMS and the Agency for Healthcare Research and Quality align harm event definitions, strengthen oversight of QAPI requirements, and direct Quality Improvement Organizations to help hospitals identify gaps in their incident reporting and surveillance systems.
The May 2022 report regarding Adverse Events in Hospitals is available here, the July 2025 report regarding uncaptured patient harm events is available here, and the companion memo to the July 2025 report is available here.
