Medicare must verify who you are when calling

Medicare can not just talk with anyone so in order to get your question answered please call prepared to answer some questions. As of May 23, 2008 Medicare customer service will not be able to assist you until you verify the providers National Provider Identifier (NPI) (line 33A of the CMS-1500 claim form) and the Provider Transaction Access Number (PTAN) which appears on line 33B of the CMS-1500 claim form.

All providers who enrolled with Medicare before May 23, 2008 their PTAN is their legacy Medicare number. New providers enrolling in Medicare on or after May 23, 2008 will be assigned a PTAN as part of the Medicare enrollment process.