For optimal diagnosis coding, get to know carriers’ ICD-9-CM guidelines, and know your state and federal diagnosis reporting requirements, says Glenn Littenberg, a Pasadena, CA, physician and member of the AMA CPT Editorial Panel.

If you demonstrate to payers that you followed their requirements, you can defend yourself if they look askance at your coding decisions. Obtain written rule documentation to safeguard your decisions. For instance, you should be aware that all paper and electronic claims that you submit to Medicare carriers must contain a valid diagnosis code, except for claims submitted by ambulance suppliers, according to a June 6, 2003 CMS program memorandum B-03-045 ( ).