Some carriers are already testing your readiness You have one less thing to worry about for Jan. 1. CMS has now bumped back its requirement to include a National Provider Identifier (NPI) in all primary fields on the claim to March 1. Starting in March, you must use your providers- NPI numbers in the billing, pay-to and rendering fields. You absolutely must have the NPI -- and only the NPI -- in all relevant fields on your claims by March 1. That includes the NPI of the referring, ordering, attending and service facility provider, CMS notes in MLN Matters article MM674. Be Prepared "Failure to submit an NPI in the primary fields will result in your claim being rejected or returned as unprocessable beginning March 1, 2008," CMS warns. Another change: CMS will allow you to use legacy numbers by themselves in secondary fields -- such as those for referring physicians -- "until further notice." That's a backtrack from the agency's earlier instruction for you to use NPIs in secondary fields by May. Start Now to Avoid Rejections Some carriers are already starting to reject your claims if you-re not using proper NPIs. Example: Noridian Administrative Services sent a notice to providers in late fall. The Part B carrier is now verifying valid matches between the NPI and the legacy identifier on claims. If they don't match, Noridian is now denying claims, the carrier warns. Best bet: Contact your clearinghouse and/or software vendor to see how they are handling this, says Rebecca Marthaller, CMRS, owner of Lower Columbia Medical Billing in Longview, Wash. "For example CollaborateMD states not to remove the legacy numbers for any insurance carriers. They will decide when and who gets what numbers. They send each carrier's claims to the clearinghouse with the carriers- requirements for each claim. This takes the responsibility and worry away from the practice's biller." Don't assume, however, that your vendor or clearinghouse is going to do this for you. If you do not have online software or do not use a clearinghouse, and instead submit claims using a carrier's Web site or other method, be sure you follow their guidelines, Marthaller says.