Summary: Since 1943 the Washington State Department of Labor and Industries has had a contract with the Department of Energy (DOE) or its predecessor to administer a self-insured workers' compensation/pension program for contractor employees at DOE's Hanford Site near Richland, Washington. This review stemmed from concerns that the contract's implementation could have prevented Hanford employees from filing workers' compensation claims for radiation-related injuries or occupational diseases resulting from their employment at the Hanford Site. GAO found that the procedures since the late 1950s for filing claims contain sufficient checks and balances to ensure they cannot be blocked by DOE. However, this assurance is lacking for claims initiated between 1943, when Hanford was founded, and the late 1950s. Claim-filing procedures in effect at that time required claims to be submitted to the state through the employer. However, no evidence was found that DOE did not forward employee claims to the state before the procedural change, nor were DOE, state officials, or employee union representatives aware of any Hanford employee being denied the right to file a workers' compensation claim.