On the CMS-1500 claim form, Box 33 identifies the billing provider — the practice submitting the claim and receiving payment — with its name, address, and phone number. Box 33a carries that provider's NPI, and Box 33b is reserved for a non-NPI identifier. This guide explains what each box means and where Pabau takes the values from.
NOTE: This article is part of the US Insurance Billing Additional Resources series, which walks through every box of the CMS-1500. If you are new to claims in Pabau, start with Creating a US Professional (CMS 1500) Claim.
Box 33 — Billing Provider Info & Phone
Box 33 holds the billing provider's name, full address, and phone number. This is the pay-to identity your payers remit against — the practice the check, the electronic payment, and the remittance advice are addressed to — so payers expect it to match what they have on file from your enrollment.
How Pabau fills it
Everything in Box 33 comes from your practice's billing profile in Setup > Claims > Claim.MD > Billing profile: the Billing organisation name, the address fields, and the Phone (10 digits). As the tab itself puts it, these details identify your practice as the billing provider on every claim submitted to Claim.MD — there is one billing profile per practice, and every claim uses it.
TIP: Enter the name and address exactly as they appear on your payer enrollment — right down to abbreviations. A billing identity that does not match what the payer has on file is a common reason payments stall.
Box 33a — Billing Provider NPI
Box 33a carries the billing provider's NPI. When a practice bills as an organization — the normal case in Pabau — this is the group (Type 2) NPI, not an individual practitioner's number.
How Pabau fills it
The value comes from the Billing NPI (group) field on the same Billing profile tab. The practitioner who actually performed the services is identified separately — the rendering provider's NPI travels on the charge lines (Box 24J) and signs the claim (Box 31), from the Providers tab of the same Setup page — while Box 33a always stays the practice-level group NPI.
On the electronic claim: the whole billing provider block is sent to Claim.MD exactly as saved in the Billing profile, and printed claims render from the same validated claim data, so paper and electronic always match.
Box 33b — Other ID Number
Box 33b is reserved for a non-NPI identifier for the billing provider — a legacy or payer-assigned number used only when a specific payer instructs it. Pabau leaves Box 33b blank. The NPI in Box 33a is the standard identifier, and for most professional claims it is all payers need.
If a payer does require a value in 33b, add it in the Claim.MD portal after sending the claim (Manage Claim), or print the claim and fill the box by hand.
The billing profile is set up once as part of connecting Claim.MD — for the full walkthrough, see Insurance Guide Part 1: Set Up the Insurance Essentials in Pabau.