What is Missouri Workers’ Comp Second Injury Fund?

Not every workplace injury happens to a worker who was previously in perfect health. Many Missourians carry old injuries, prior amputations, service related conditions, or lingering impairments from years earlier when a new workplace accident occurs. When a preexisting condition combines with a new work injury to leave someone permanently and totally disabled, Missouri’s Second Injury Fund can become an important source of compensation, separate from what the employer’s workers’ compensation insurance pays. Understanding how this fund works, and how significantly the rules changed in 2014, is essential for any injured Missouri worker who has a history of prior injury or disability.

The Purpose Behind Missouri’s Workers’ Compensation Second Injury Fund

The Second Injury Fund is a special fund maintained by the State of Missouri, created under RSMo 287.220. Its original purpose was to solve a practical problem in the workers’ compensation system. Without some kind of safety net, an employer who hired a worker with a preexisting disability could become fully liable for a much larger, combined disability if that worker was ever hurt again on the job, even though the employer had nothing to do with causing the earlier injury. That kind of exposure discouraged employers from hiring workers who had prior injuries, amputations, or other disabilities.

The Second Injury Fund addresses this by shifting part of the financial responsibility away from the employer. When a work injury combines with a qualifying preexisting disability to produce a greater overall disability than the new injury would have caused on its own, the employer remains responsible only for the disability caused by the new injury, and the fund covers the additional, combined portion. This structure is meant to encourage employers to hire and retain workers with disabilities, rather than viewing them as a greater financial risk.

How the Fund Is Financed

The Second Injury Fund does not draw from general state tax revenue. It is funded through a surcharge assessed on workers’ compensation insurance carriers and self-insured employers under RSMo 287.715. For calendar year 2026, the Missouri Department of Labor and Industrial Relations has set the Second Injury Fund surcharge at 3.0 percent, with no additional supplemental surcharge currently in effect. These funds are collected quarterly and used to pay the fund’s ongoing benefit obligations, legal defense costs, and administrative expenses. The fund’s solvency is closely monitored, and Missouri law requires an annual actuarial study to evaluate the fund’s balance and projected future liabilities.

The Critical Dividing Line: January 1, 2014

Anyone researching the Second Injury Fund needs to understand that Missouri dramatically overhauled how the fund operates for injuries occurring on or after January 1, 2014. The rules are fundamentally different depending on which side of that date an injury falls.

For injuries that occurred before January 1, 2014, the fund could compensate a broader range of claims, including permanent partial disability claims where a preexisting disability combined with a new work injury to produce a substantially greater combined disability than the new injury alone would have caused. These older claims followed a more generous threshold system based on weeks of compensation or percentage of disability to a body part.

For injuries occurring on or after January 1, 2014, the rules narrowed considerably. Under current law, no claims for permanent partial disability may be filed against the Second Injury Fund at all. The fund now compensates only claims for permanent total disability, meaning the worker is unable to work in any capacity as a result of the combined effect of the preexisting condition and the new injury.

What Counts as a Qualifying Preexisting Disability Today

Because permanent total disability claims are now the only claims the fund will pay, Missouri law is specific about what qualifies as a preexisting disability for post-2014 injuries. Under RSMo 287.220.3, a worker must have a medically documented preexisting disability equal to a minimum of fifty weeks of permanent partial disability compensation, and that preexisting disability must fall into one of several defined categories. It must be a direct result of active military duty in any branch of the United States Armed Forces, a direct result of a prior compensable work injury, a condition that directly and significantly aggravates or accelerates the new work injury, or a preexisting permanent partial disability of an extremity, an eye, or an ear, where the new work injury affects the corresponding body part on the opposite side.

Missouri law also extends fund eligibility to certain workers employed in sheltered workshop programs who sustain a compensable work injury that combines with a preexisting disability to cause permanent total disability.

If the preexisting condition does not fall into one of these narrow categories, or if the combined disabilities result in something less than permanent total disability, the Second Injury Fund generally has no liability under current law, even though the fund might have covered a similar claim before 2014.

Related: Understanding Missouri’s Workers’ Compensation Laws and Requirements

How Second Injury Fund Claims Work in Practice

When a Second Injury Fund claim is pursued, the process runs alongside a worker’s regular workers’ compensation claim against the employer. An administrative law judge with Missouri’s Division of Workers’ Compensation first determines what the employer owes for the new injury considered on its own. If the combination of the new injury and the qualifying preexisting disability results in permanent total disability, the employer is generally responsible only for the disability caused by the new work injury by itself, and the Second Injury Fund becomes responsible for the remainder needed to provide permanent total disability benefits.

The Missouri State Treasurer serves as the custodian of the fund and is named as a party in these claims, with the Missouri Attorney General’s office providing legal representation to defend the fund against the claim. Because the fund actively defends against claims made against it, workers pursuing a Second Injury Fund claim should expect the same kind of adversarial process they would face from a private insurance carrier, including independent medical examinations, discovery, and potentially a contested hearing.

Other Situations Involving the Fund

Beyond permanent total disability claims involving preexisting conditions, the Second Injury Fund also serves another important role. When an employer illegally fails to carry required workers’ compensation insurance, the fund may be used to help cover an injured worker’s medical expenses tied to injuries occurring before January 1, 2014, consistent with Missouri’s rules for uninsured employer claims. Missouri law also permits the Attorney General’s office to pursue reimbursement from an uninsured employer for any funds the Second Injury Fund pays out on that employer’s behalf.

Why This Matters for Injured Missouri Workers

For workers with a history of a prior workplace injury, a service connected disability, or an old injury to a hand, eye, or other extremity, the Second Injury Fund can mean the difference between limited benefits and full permanent total disability compensation when a new work injury pushes them over the edge into total disability. But because the current law is narrower than it once was, and because it applies only to permanent total disability claims for injuries after January 1, 2014, many injured workers assume they have no claim against the fund when they may, in fact, qualify, or they pursue a claim that no longer exists under the post-2014 rules.

Given how technical the qualifying categories are, and how aggressively the fund is defended by the Attorney General’s office, workers who believe a preexisting condition may have contributed to a permanent total disability should have their claim evaluated carefully. An experienced Missouri workers’ compensation attorney can determine whether a preexisting condition meets the fund’s current legal requirements and can help ensure that a worker who is entitled to Second Injury Fund benefits does not leave that compensation unclaimed.