UB-04 Guide

UB-04 Claim Form Guide

Field-by-field reference, billing tips, and practical insights from processing thousands of UB-04 claims.

Understanding the UB-04 Form in 2026

The UB-04 (also known as the CMS-1450) is the standard claim form used by hospitals, skilled nursing facilities, and other institutional providers to bill Medicare, Medicaid, and commercial insurance.

At FormJuicer, we process thousands of UB-04 documents every month. The most common problems we see are incorrect data in high-risk fields (especially Type of Bill, Revenue Codes, Diagnosis, and Patient Information), which lead to immediate rejections or payment delays.

This guide breaks down every major field with practical explanations, common errors, and how each field maps to the rules our browser-based claim audit checks.

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Why Accurate UB-04 Data Matters

One wrong digit in the Type of Bill or Revenue Code can cause full claim rejection. In our 2025–2026 data, TOB and diagnosis coding errors were responsible for a large percentage of first-pass denials.

FormJuicer audits UB-04 claims against the same rules payers apply — checking types of bill, revenue code pairings, diagnosis coding, and required fields before the claim reaches adjudication.

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Run a sample UB-04 audit in your browser and see every flag explained — before your claim meets a payer.

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Last Updated: April 30, 2026

This guide is based on official CMS and NUBC guidelines. Always verify billing requirements with your payer.