Governor Tony Evers signed Assembly Bill 651 on April 6, 2026, enacting 2025 Wisconsin Act 145. The law extends workers’ compensation PTSD presumption coverage to emergency medical responders, EMS practitioners, and volunteer or part-time firefighters, applying the same standards already in place for law enforcement officers and full-time firefighters.
The bill was developed through Wisconsin’s Workers Compensation Advisory Council, a consensus body representing labor and management. It also raises the maximum weekly compensation rate for permanent total disability, expands supplemental benefits eligibility, and eliminates the statute of limitations for traumatic injuries requiring shoulder replacement.
Who it affects
Self-insured municipalities, counties, and special districts that employ or contract with EMS personnel and volunteer fire departments face the most direct exposure. Wisconsin has hundreds of volunteer and combination fire departments, many of which also provide ambulance services. Public entities that carry their own workers’ comp risk for these workers now have an expanded class of eligible mental health claims under a rebuttable presumption framework. Hospital-based EMS programs with self-insured WC exposure should also take note.
The reserve mechanism
The primary reserve impact is a frequency increase. Before Act 145, EMS workers and volunteer firefighters filing a PTSD claim had to meet Wisconsin’s standard mental-mental injury threshold, which requires proof that workplace conditions were extraordinary compared to normal employment. The new presumption shifts the burden: the employer must now rebut the presumption that a diagnosed PTSD condition is work-related. This lower barrier will produce claims that would not have been filed, or would have been denied, under the old standard.
The secondary effect is a development pattern lengthening. PTSD claims differ from physical-injury workers’ comp claims in ways that matter for the loss development triangle. Treatment is often extended, with therapy courses running 12 to 24 months or longer. Relapse is common, meaning claims that appear closed can reopen. These characteristics push paid development further into the tail, which means standard link ratios (cumulative development factors) derived from historical physical-injury patterns will understate the ultimate cost of a growing mental-health claim population.
Act 145 also increases the maximum weekly compensation rate for permanent total disability. For the subset of PTSD claims that result in a total disability finding, this raises the per-claim severity. The stacking prohibition (which bars adding permanent partial disability ratings for repeat procedures on the same limb) provides a modest offset on the physical-injury side, but it does not offset the mental-health frequency expansion.
What to ask your actuary
- How many emergency medical responders, EMS practitioners, and volunteer or part-time firefighters are currently covered under our WC program, and what incremental PTSD claim frequency should we model now that the presumption applies?
- Should we segment mental-health claims into a separate development triangle (or at least separate link ratios) so that the longer tail does not get blended into and distorted by physical-injury development patterns?
- Has our case reserving protocol for psychological injury claims been updated to reflect the higher recurrence rates typical of first-responder PTSD?
What to watch next
Two developments will clarify the size of the exposure. First, whether NCCI files a loss cost adjustment for Wisconsin reflecting the expanded presumption classes, which would signal that the rating bureau sees a measurable frequency shift. Second, whether Assembly Bill 778, which would further amend the conditions for PTSD presumption claims, advances in the current legislative session. Wisconsin joins Connecticut, Montana, Kentucky, and Oklahoma in expanding mental-health WC presumptions in 2026, so the pattern is worth watching beyond a single state.