Most inpatient diagnostic error claims come from general medical-surgical units rather than intensive care, according to new closed-claims analysis from Coverys.
The insurer said the gaps in patient monitoring on those wards are a key driver of severe and costly outcomes.
The Massachusetts-based medical professional liability (MPL) carrier reviewed 403 closed inpatient diagnostic error events from 2021 to 2025. General medical-surgical units accounted for 68% of them, compared with 16% in critical care. The results appear in the third part of Coverys' series on the drivers of diagnostic error, which focuses on hospital stays.
Across Coverys' wider dataset of 6,302 closed claims, diagnostic-related events made up 28% of claims but 43% of total indemnity paid across all care settings. That was the largest financial impact of any category.
The inpatient claims involved serious harm. Some 55% of events resulted in a patient's death, and a further 19% caused high-severity, permanent injury.
More than three-quarters involved patients with underlying comorbidities. More than 90% involved factors in clinical decision-making, such as diagnostic differentials affected by testing issues or cognitive bias.
Hospitalist medicine was the specialty most often involved, accounting for 37% of inpatient diagnostic events and 30% of indemnity paid.
"Our data shows that general medical-surgical units, where monitoring is periodic rather than continuous, represent specific vulnerabilities," said Dana Siegal, vice president of risk management and analytics at Coverys.
Siegal said inpatient diagnostic errors rarely come down to a single oversight. She described them as a systemic problem caused by breakdowns in information and communication, made worse by patient complexity and heavy workloads.
The report recommends standardized processes for monitoring and communicating patient assessments, and "diagnostic time-outs" when patients don't respond to treatment as expected. It also recommends bringing clinical pharmacists into diagnostic teams for complex infection cases, and actively incorporating concerns raised by patients and families. Coverys has also published a self-assessment tool that hospitals can use to evaluate their diagnostic processes, escalation of vital signs, shift handoffs and safety culture.
The findings come as hospitals face rising MPL costs. S&P Global Market Intelligence estimated that MPL produced a calendar-year combined ratio above 105% in 2025, the fifth time in eight years. American Medical Association data showed that 39.9% of reported MPL premiums rose year on year in 2025, the second-highest share since 2005.
Coverys is among the larger writers in the line, holding a market share of about 3.8%, according to Insurance Business's ranking of the top medical malpractice insurers.
For brokers placing hospital professional liability, the report points to where underwriters are likely to look hardest. Diagnostic claims on general wards involve high death rates and large indemnity payments, which makes them exactly the losses that drive severity and erode excess layers.
Hospitals that can show structured handoffs, clear rules for escalating vital signs, and diagnostic review processes for patients who aren't improving will be in a stronger position at renewal. The self-assessment tool gives brokers a ready framework for gathering that evidence before submission. With the market still under pressure, a documented risk management program on general medical-surgical units could make a meaningful difference to terms.
