Claim Forms Guide

UB-04 Claim Form, Locator by Locator

The UB-04 (CMS-1450) is the uniform bill for facility claims - 81 form locators covering hospitals, skilled nursing, home health and hospice. The electronic twin is the 837I. Facility billing runs on bill types and revenue codes, a different language from professional claims.

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The Basics

What the UB-04 Is

Four facts about the facility claim form.

81 Form Locators

FL01 through FL81. Every locator has a defined purpose, from provider identifiers to diagnosis codes to payer details.

837I Is the Electronic Twin

Electronic facility claims go as 837I transactions. The locators map to 837I loops - same data, structured for systems.

Bill Type in FL04

Four characters that tell the payer everything: facility type, bill classification, frequency. 0111 means hospital inpatient, admit through discharge.

Revenue Codes Drive Payment

FL42-49 carry revenue codes (0100-0999) - room and board, pharmacy, lab, radiology. The revenue code tells the payer what kind of charge each line is.

Key Locators

The Form Locators That Decide Payment

The fields that make or break a facility claim.

Locator	Field	Why it matters
FL01	Billing provider name, address, phone	Must match enrollment exactly.
FL04	Type of bill	Four-digit code: facility type + classification + frequency. Wrong bill type, wrong processing.
FL06	Statement covers period	From and through dates of the billing period. Drives timely filing math.
FL12-17	Patient details	Admission date, status, discharge hour - all feed medical review.
FL42-49	Revenue code lines	Each line pairs a revenue code with HCPCS, dates, units and charges.
FL50	Payer name	Primary, secondary, tertiary in A, B, C lines. Order errors cause COB denials.
FL67	Principal diagnosis	The main reason for the encounter. Drives DRG grouping for inpatient claims.
FL76-79	Occurrence codes and dates	Events like accidents or onset dates that affect coverage decisions.

Bill Types

Common UB-04 Bill Types

The first digit is facility type, the second is classification, the third and fourth are frequency.

Bill type	Meaning	Used for
0111	Hospital inpatient, admit through discharge	Standard inpatient hospital claim.
0121	Hospital inpatient Part B	Ancillary Part B services for an inpatient.
0131	Hospital outpatient	Outpatient hospital services, including observation.
0141	Hospital other Part B	Part B only services from a hospital.
0321	Home health, admit through discharge	Home health agency claims.
0811	Hospice, admit through discharge	Hospice claims - note the non-routine bill type series.

FAQ

Questions, Answered

Straight answers, no jargon.

How many form locators are on the UB-04?

81, numbered FL01 through FL81.

What is the difference between the UB-04 and the CMS-1500?

The UB-04 (CMS-1450) is for facility/institutional claims - hospitals, SNFs, home health, hospice. The CMS-1500 is for professional claims - physicians and suppliers. They use different data: bill types and revenue codes vs procedure boxes.

What is a bill type?

The four-character code in FL04. Digit 1 is facility type (1 hospital, 3 home health, 8 hospice), digit 2 is bill classification, digits 3-4 are frequency (1 admit through discharge, 7 replacement, 8 void).

What are revenue codes?

Four-digit codes (0100-0999) in FL42 that classify each charge line - 0110 room and board, 0250 pharmacy, 0300 lab, 0450 emergency room. Payers use them to route lines to the right pricing logic.

What is the 837I?

The electronic version of the UB-04. Nearly all facility claims transmit as 837I through a clearinghouse, with form locators mapped to transaction loops.

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