Distinguish "from" and "through" dates. You know you'll need to start using ICD-10 diagnosis codes for services provided on or after Oct. 1, 2013 -- but what about claims for services that begin prior to Oct. 1 and end on or after that date? Example: You can't report both ICD-9 and ICD-10 codes on the same claim CMS has said -- those claims will be returned to providers unpaid and marked as "unprocessable." In an "ICD-10 National Provider Teleconference", CMS's Sarah Shirey-Losso stated that "Some claims will continue to use the discharge date, some will use the 'from' date, and some may be required to be split," but indicated that specific instruction would be forthcoming. Follow Guidance Transmittal 950 Providers recently received the promised guidance for different provider types when CMS issued Transmittal 950, which breaks down how each facility and provider should report claims that span the ICD-10 implementation date. Following you'll find some examples of how various entities will report these claims: Inpatient hospitals: Providers, Part B hospital services, outpatient hospitals, hospices, and outpatient home health: Expect return, not denial: "For dates of service on or after October 1, 2013, claims may not contain ICD-9 codes. Please re-submit claim with the appropriate ICD-10 code." To read Transmittal 950, which includes the full list of potential provider types, visit www.cms.gov/transmittals/downloads/R950OTN.pdf.