The Centers for Medicare & Medicaid Services (CMS) implemented the Comprehensive Error Rate Testing (CERT) program to measure improper payments in the Medicare Fee-for-Service (FFS) program.  CERT is designed to comply with the Improper Payments Information Act (IPIA) of 2002, as amended by the Improper Payments Elimination and Recovery Improvement Act (IPERIA) of 2012.  IPIA and IPERIA require the heads of Federal agencies, including the Department of Health and Human Services (HHS), to annually review programs it administers to improve agency efforts to reduce and recover improper payments. The Medicare FFS improper payment rate was first measured in 1996. HHS Office of Inspector General (OIG) was responsible for estimating the national Medicare FFS improper payment rate from 1996 through 2002. Based on available resources, OIG reviewed about 6,000 claims.  Currently CERT selects a stratified random sample of approximately 50,000 claims submitted to Part A/B Medicare Administrative Contractors (MACs) and Durable Medical...