The final rule adopting the National Provider Identifier ("NPI"), which is the standard unique health identifier for health care providers, was published in the Federal Register on Friday, January 23, 2004. The effective date of this final rule will be May 23, 2005. The NPI, to be issued through the National Provider System that CMS is in the process of developing, will replace all "legacy" identifiers. All health care providers, not just covered entities, are eligible for an NPI; covered entities, however, must obtain an NPI and must use NPIs in Standard Transactions as of May 23, 2007 (small health plans, May 23, 2008). Health care providers do not need to take any action to apply for NPIs at this time. CMS' National Provider System will be ready to accept applications after the effective date of this final rule (May 23, 2005). The final rule governing the Standard Unique Employer Identifier was published May 31, 2002. CMS announced that the standards for unique identifiers for
