7.3 UB-04 / CMS-1450 (Institutional) Claim

Purpose of the UB-04

The UB-04, formally the CMS-1450, is the standard claim form for institutional providers — hospitals (inpatient and outpatient), skilled nursing facilities, home health agencies, hospice, and other facilities. It is maintained by the National Uniform Billing Committee (NUBC). The electronic equivalent is the 837I (I for institutional).

Unlike the CMS-1500's 33 boxes, the UB-04 has 81 numbered fields called Form Locators (FLs).

FL 4: Type of Bill (TOB)

The Type of Bill is a coded value (commonly shown as a four-digit field with a leading zero) where each digit position has a meaning:

Reading TOB ranges as "x" placeholders for the frequency digit:

So 0111 is a hospital inpatient admit-through-discharge claim, and 0137 is a hospital outpatient replacement claim.

FL 42: Revenue Codes

Revenue codes in FL 42 classify every charge line by the department or type of service that produced it. Each revenue line pairs with a charge amount and, for outpatient claims, often a CPT/HCPCS code.

Occurrence and Value Codes

Institutional claims also carry coded supplemental data:

• Occurrence codes (FLs 31–34) report a dated event — accident date, onset of symptoms, or the date a benefit period started.
• Occurrence span codes (FL 35–36) report a date range, such as a qualifying inpatient stay before SNF care.
• Value codes (FLs 39–41) report a code paired with a dollar amount or numeric value — for example, the most common semi-private room rate or blood deductible.
• Condition codes (FLs 18–28) flag special situations affecting adjudication.

CMS-1500 vs UB-04: Choosing the Right Form

The deciding factor is who is billing, not the patient's diagnosis. A physician who treats a patient inside a hospital still bills the CMS-1500/837P for the professional component; the hospital bills the UB-04/837I for the facility component (room, nursing, supplies). Many inpatient encounters therefore generate both a professional and an institutional claim.