Loop 2010AA, 2010AB/FL 5 | Medicare Billing: CMS-1450 & 837I

Table 6: Loop 2010AA, 2010AB/FL 5 Field
Federal Tax ID Number	Source
Enter the federal tax ID number assigned to the provider by the federal government for tax reporting purposes.	Provider records

We also refer to the federal tax ID number as the Tax Identification Number (TIN) or the employer identification number (EIN). The format is NN-NNNNNNN.