Effective Nov. 16, 2026, we’ll no longer accept commercial and Medicare claims submitted with a P.O. Box in the Billing Provider address field. These claims will be front-end rejected back to the provider. This already applies to Medicaid claims and is in alignment with HIPAA standard and NUCC guidance.
Billing guidance
Use a street address* in the following fields:
- CMS-1500 (paper): Item 33
- UB-04 (paper): Field 1
- 837P (electronic): Loop 2010AA – Segment N3*01 (if you need to send a P.O. Box, you can do so in Loop 2010AB – Segment N3*01)
*If you don’t have a street address, you can use your servicing location address.
Identifying front-end rejections
Find your front-end rejections and the reasons for them in our portal’s Claims tool. Use the Up-Front Rejected Claims search to locate your claim. We also notify providers by a front-end rejection letter or, if the claim was submitted electronically, via EDI transaction 277CA.
After you review the front-end rejection letter or 277CA, you can make the necessary corrections and submit a new claim. A "corrected claim" is not required.