A complete guide to UB-04 forms
At a glance
- A UB-04 form is the standard claim form institutional healthcare facilities use to bill payers. It is also known as the CMS-1450.
- The National Uniform Billing Committee (NUBC) maintains the form, and the Centers for Medicare & Medicaid Services (CMS) originally created it.
- Facilities use the UB-04 for institutional billing, while individual clinicians and group practices generally use the CMS-1500.
- The UB-04 has 81 fields, called Form Locators, that capture client demographics, service and revenue codes, and billing details.
Table Of contents
A UB-04 form is the standard claim form that institutional healthcare facilities use to bill payers for services. Also called the CMS-1450, it’s maintained by the National Uniform Billing Committee (NUBC) and uses 81 fields, known as Form Locators, to capture client, service, and billing details. Facilities such as hospitals, residential treatment centers, and inpatient behavioral health programs bill on the UB-04, while individual clinicians and group practices typically use the CMS-1500 instead.
Getting the form right matters, because a single missing or mismatched field can hold up payment. This guide covers what the UB-04 form is, when to use it instead of the CMS-1500, how to fill it out, and what each Form Locator captures.
What is a UB-04 form?
The UB-04 form is the standard claim form institutional facilities use to submit healthcare claims to payers. It’s maintained by the National Uniform Billing Committee (NUBC) and is also known as the CMS-1450, the name it carries from the Centers for Medicare & Medicaid Services (CMS), which created it. You will sometimes see it written without the hyphen, as UB04, but it refers to the same form.
Over time, the UB-04 has become the standard for institutional billing and is recognized by essentially every major payer. 98% of hospital claims for healthcare providers such as hospitals are submitted electronically using UB-04 forms electronically rather than on paper, though completing the form itself is still a manual, detail-heavy task for many billing teams.
Once you submit a UB-04, the payer runs it through the claims adjudication process to decide whether and how much to pay. The cleaner your form, the smoother that review tends to go.
Why the UB-04 form matters for your practice
The UB-04 matters because it is the form most major payers require for institutional claims across a wide range of client conditions and treatments. It can be detailed, but it is a far better option than piecing together separate forms, and it cuts down the administrative load for you and your billing team. Filing accurate claims the first time is one of the most reliable ways to protect a steady revenue stream, which helps you absorb other pressures like payer mix changes and shifting regulations.
UB-04 form vs CMS-1500: which one to use
The UB-04 and the CMS-1500 exist for the same reason, uniform and simplified billing, but they differ in layout and coding structure, and they are not interchangeable. The distinction comes down to who is billing and for what.
The UB-04 is for institutional and facility billing. The CMS-1500 is for professional billing by individual clinicians and group practices.
For behavioral health specifically, this is worth spelling out, because it is a common point of confusion. Most outpatient behavioral health practices bill their professional services on the CMS-1500. Facility-based programs, such as inpatient psychiatric units, residential treatment centers, and many partial hospitalization or intensive outpatient programs, bill on the UB-04. In other words, the setting and the type of billing decide the form, not the fact that the care is behavioral health.
| UB-04 form (CMS-1450) | CMS-1500 | |
|---|---|---|
| Used for | Institutional and facility billing | Professional billing by individual clinicians |
| Typical filers | Hospitals, facilities, and institutional billing teams | Solo clinicians and group practices |
| Behavioral health examples | Inpatient psychiatric care, residential treatment, partial hospitalization and intensive outpatient programs | Outpatient therapy and private practice |
| Maintained by | National Uniform Billing Committee (NUBC) | National Uniform Claim Committee (NUCC) |
When you are unsure which form a specific payer expects for a specific service, confirm it with the payer before you submit.
Filling out a UB-04 form: tips to get it right
The UB-04 has a lot of fields, and small mistakes are the ones that hold up payment most often. A few habits make the form easier to complete correctly:
- Check each payer’s requirements, since they can differ from one payer to the next.
- Have your 10-digit National Provider Identifier (NPI) and the necessary tax ID numbers on hand.
- Learn the Form Locators (FLs), the 81 separate fields on the UB-04, and what each one needs.
- Know when to use specific procedure codes and diagnosis codes, and use current ICD-10 codes where required.
- Consult the NUBC manual for accurate codes rather than relying on memory.
- Enter client information exactly as it appears on the insurance card.
Breaking down the UB-04 form locators
The UB-04 has 81 fields, called Form Locators. Each one has a specific purpose and calls for particular information. The table below summarizes what belongs in each. Where a Form Locator is marked “not used,” it is left blank on the standard form.
| Form Locator | What to enter |
|---|---|
| FL 1 | Billing facility name, address, and contact details (name; street address; city, state, ZIP; telephone, fax, country code) |
| FL 2 | Pay-to name and address, only if different from FL 1 |
| FL 3a/b | Client number and medical record number |
| FL 4 | Type of bill (TOB), a four-digit code (leading zero; two digits for bill type; final digit for frequency) |
| FL 5 | Federal tax number |
| FL 6 | Statement covers period, “from” and “through” dates (MMDDYY); for single-day billing, enter the same date in both |
| FL 7 | Not used |
| FL 8 | Client’s name (last, first, MI) |
| FL 9 | Client’s mailing address (street or PO box, city, state, ZIP) |
| FL 10 | Client’s date of birth |
| FL 11 | Client’s sex |
| FL 12 | Admission or start-of-care date |
| FL 13 | Admission hour, in military time (2 characters) |
| FL 14 | Priority of the visit (1-digit code) |
| FL 15 | Source of referral for the visit (1-digit code) |
| FL 16 | Discharge hour, in military time (2 characters) |
| FL 17 | Client discharge status (2-digit code from the NUBC manual) |
| FL 18-28 | Condition codes (from the NUBC manual) |
| FL 29 | Accident state code (2-digit code from the NUBC manual) |
| FL 30 | Not used |
| FL 31-34 | Occurrence codes and dates (from the NUBC manual) |
| FL 35-36 | Occurrence span codes and dates (MMDDYY) |
| FL 37 | Not used |
| FL 38 | Name and address of the party responsible for the bill |
| FL 39-41 | Value codes and amounts for special circumstances (from the NUBC manual) |
| FL 42 | Revenue code (from the NUBC manual) |
| FL 43 | Revenue code description, IDE number, or Medicaid drug rebate NDC |
| FL 44 | HCPCS code, HIPPS rate code, or accommodation rate code |
| FL 45 | Service date (MMDDYY) |
| FL 46 | Units of service (visits, days, and so on) |
| FL 47 | Total charges for the revenue code in FL 42 |
| FL 48 | Non-covered charges for the revenue code in FL 42 |
| FL 49 | Not used |
| FL 50 | Payers, listed in order of liability (primary, secondary, tertiary) |
| FL 51 | Health plan ID for each payer in FL 50 |
| FL 52 | Release-of-information code for each payer in FL 50 |
| FL 53 | Assignment-of-benefits indicator for each payer in FL 50 |
| FL 54 | Prior payments received toward the bill (dollars and cents) |
| FL 55 | Estimated amount due |
| FL 56 | Billing facility’s 10-digit National Provider Identifier (NPI) |
| FL 57 | Other provider ID, if required |
| FL 58 | Insured’s name |
| FL 59 | Client’s relationship to the insured |
| FL 60 | Insured’s unique identifier (member ID) |
| FL 61 | Insured’s group name |
| FL 62 | Insured’s group number |
| FL 63 | Treatment authorization code |
| FL 64 | Document control number (internal control number) |
| FL 65 | Employer name |
| FL 66 | Diagnosis and procedure code qualifier (indicates the ICD version, currently ICD-10) |
| FL 67 | Principal ICD-10-CM diagnosis code and present-on-admission (POA) indicators |
| FL 68 | Not used |
| FL 69 | Admitting ICD-10-CM diagnosis code |
| FL 70 | Client’s reason-for-visit codes |
| FL 71 | Not used |
| FL 72 | External cause of injury ICD-10-CM code |
| FL 73 | Not used |
| FL 74 | Principal procedure code and date, plus other procedure codes |
| FL 75 | Not used |
| FL 76 | Attending provider name and identifiers |
| FL 77 | Operating physician name and ID |
| FL 78-79 | Other provider names and identifiers |
| FL 80 | Remarks |
| FL 81 | Additional codes or overflow from another Form Locator |
With a clear understanding of the requirements, you and your billing team can manage these forms efficiently and keep claims moving through billing and processing.
Submitting UB-04 forms electronically
Filling out UB-04 forms by hand is slow and easy to get wrong, and a rejected claim means chasing payment you have already earned. The right billing software can generate and submit UB-04 forms electronically, apply the payer-specific rules and revenue codes that behavioral health billing depends on, and route claims through an electronic claims clearinghouse that checks them for errors before they reach the payer.
Catching a missing code or a mismatched client detail before submission is what keeps a claim out of the rejection and denial pile, so more of your UB-04 claims move toward payment the first time.
Additional resources
Experience the Ensora Health difference.
See how we can transform your practice.
