IMPORTANCE Each year, millions of persons worldwide seek compensation for transport accident and workplace injuries. Previous research suggests that these claimants have worse long-term health outcomes than persons whose injuries fall outside compensation schemes. However, existing studies have substantial methodological weaknesses and have not identified which aspects of the claiming experience may drive these effects. OBJECTIVE To determine aspects of claims processes that claimants to transport accident and workers' compensation schemes find stressful and whether such stressful experiences are associated with poorer long-term recovery. DESIGN, SETTING, AND PARTICIPANTS Prospective cohort study of a random sample of 1010 patients hospitalized in 3 Australian states for injuries from 2004 through 2006. At 6-year follow-up, we interviewed 332 participants who had claimed compensation from transport accident and workers' compensation schemes ("claimants") to determine which aspects of the claiming experience they found stressful. We used multivariable regression analysis to test for associations between compensation-related stress and health status at 6 years, adjusting for baseline determinants of long-term health status and predisposition to stressful experiences (via propensity scores). MAIN OUTCOMES AND MEASURES Disability, quality of life, anxiety, and depression. RESULTS Among claimants, 33.9% reported high levels of stress associated with understanding what they needed to do for their claim; 30.4%, with claim delays; 26.9%, with the number of medical assessments; and 26.1%, with the amount of compensation they received. Six years after their injury, claimants who reported high levels of stress had significantly higher levels of disability (+6.94 points, World Health Organization Disability Assessment Schedule sum score), anxiety and depression (+1.89 points and +2.61 points, respectively, Hospital Anxiety and Depression Scale), and lower quality of life (−0.73 points, World Health Organization Quality of Life instrument, overall item), compared with other claimants. Adjusting for claimants' vulnerability to stress attenuated the strength of these associations, but most remained strong and statistically significant. CONCLUSIONS AND RELEVANCE Many claimants experience high levels of stress from engaging with injury compensation schemes, and this experience is positively correlated with poor long-term recovery. Intervening early to boost resilience among those at risk of stressful claims experiences and redesigning compensation processes to reduce their stressfulness may improve recovery and save money.