The Centers for Medicare and Medicaid Services (CMS) clarified in Transmittal 1478 (CR 5923), released March 14, 2008, that providers are not to use the JW modifier on claims submitted under the Competitive Acquisition Program (CAP). CAP is the alternative to the average sales price (ASP) system in which physicians opt to buy and bill Part B drugs and biologicals from approved vendors in a competitive bidding process.
The JW modifier is used to identify unused Part B drugs and biologicals from a single vial or package. CMS started to reimburse for discarded drugs and biologicals from single-use vials and packages as of July 1, 2007. Payment is provided for the amount of the drug or biological administered and amount discarded up to the total amount of the drug indicated on the vial or the package as long as the JW modifier is used.
Further information can be obtained from the CMS Web site.