The new ICD-9 diagnosis codes went into effect on October 1st, 2004. In the past years, we had a three month grace period to use the new and revised codes. This year in 2004, CMS eliminated the grace period. Which means claims are going to be denied if you have not updated your diagnosis codes. If you have not already, you can view or download the 2004 code updates by visiting http://www.cms.hhs.gov/medlearn/icd9code.asp. Those interested in the proposed new diagnosis coding sytem, ICD-10-CM, being developed as a replacement for ICD-9-CM, volumes 1 and 2, should visit http://www.cdc.gov/nchs/icd9.htm