The OIG has reviewed the extent to which states have improved collection of third-party liability (TPL) payments in situations where Medicaid beneficiaries have additional sources of health insurance that are responsible for payment. According to the OIG report, Medicaid Third-Party Liability Savings Increased, But Challenges Remain, states reported that TPL savings increased from almost $34 billion in 2001 to more than $72 billion in 2011. Nevertheless, states generally were not able to recover all of third-party obligations, leaving an estimated $4 billion at risk of not being recovered. The OIG recommends that CMS: work with states to address longstanding challenges related to identification of insurance coverage and recovery of payments; address states' challenges with 1-year timely filing limits for Medicare and TRICARE; and strengthen enforcement mechanisms designed to deal with uncooperative third parties. CMS concurred with the recommendations.