UB-04 Claim Form (CMS-1450)

What the UB-04 is

The UB-04 Claim Form, also known as CMS-1450, is the institutional claim form that facilities use to bill Medicare, Medicaid, and commercial payers. It is used for inpatient, outpatient hospital, and facility-based behavioral-health services, and is the paper counterpart to the 837I electronic claim.

The form is heavily field-driven. Key areas include:

• Type of Bill (TOB) that signals inpatient, outpatient, interim, or final bill
• Statement From/Through dates that define the billing period
• Condition, occurrence, and value codes that describe clinical and financial context
• Covered and non-covered days for per-diem stays
• Revenue codes, HCPCS/CPT, units, and charges on service lines
• Patient status at discharge (still a patient, transferred, left AMA, expired)

For behavioral health, the UB-04 is the primary vehicle for facility-level billing for residential treatment, detox, PHP, IOP, and hospital-based psych units. Professional services during the stay usually bill separately on a CMS-1500.

Why the UB-04 matters operationally

Errors on a UB-04 skip past simple coding fixes and trigger hard denials, underpayments, and payment delays. Revenue codes, type of bill, statement dates, and covered days drive grouper and payer logic. When those fields are wrong, the payer may:

• Reject the claim as unprocessable (CO-16, MA130)
• Deny all or part of the stay as not covered (CO-50, CO-97, PR-96)
• Pay the wrong per-diem or case rate and apply contractual reductions (CO-45)

Across a residential or PHP program, one bad rule in how UB-04s populate can backlog an entire month of claims. A wrong patient status code, mismatched occurrence span dates, or missing auth number can hold tens or hundreds of thousands of dollars in AR until staff correct and rebill.

Accurate completion of the UB-04 also protects you in audits. Fields like occurrence span dates, condition codes, and value codes must line up with documented medical necessity and authorization. When they do not, payers have an easier time recouping past payments.

How UB-04s are used and read day to day

RCM and billing teams rarely fill out UB-04s by hand. Practice management and hospital billing systems generate the electronic 837I from encounter data, then render a UB-04 view. Operators use this view to confirm that facility, episode, and service details line up with payer rules.

Key UB-04 areas to check before submission:

• Type of Bill (FL 4): correct setting and claim frequency (original, interim, corrected)
• Statement dates (FL 6): align with admission, discharge, and authorization span
• Patient status (FL 17): accurate discharge or still-a-patient status
• Condition, occurrence, and value codes (FL 18-39): required by many Medicaid and commercial plans for behavioral health
• Covered / non-covered days (FL 39-41 / FL 46 by units): match UR decisions and concurrent auth
• Revenue codes, HCPCS/CPT, units, and charges (FL 42-47): right mix of per-diem versus ancillary services
• Payer and subscriber fields, including authorization number (FL 50-63): match benefits-verification and auth records

On the back end, payers and clearinghouses convert the UB-04 or 837I into adjudication data you see on the 835 remittance advice. When you triage a denial, you often pull up the stored UB-04 image side by side with the remit to spot where the data broke payer rules.

• Billing behavioral-health residential stays with an outpatient Type of Bill (for example, 013X instead of 011X), which causes Medicaid or commercial payers to reject the whole claim as an invalid service setting (CO-16, MA130).
• Letting the Statement From/Through dates run beyond the approved concurrent auth span on a per-diem PHP or IOP claim, so units past the auth deny as not covered (CO-197, N130) and require split claims and appeals.
• Putting all days as covered on a long residential stay when UR has denied specific days, which leads to partial recoupments or CO-97 / CO-50 denials in audit rather than clean up-front adjustments with clear non-covered days.
• Using generic or hospital-medical revenue codes instead of behavioral-health specific ones (for example, 0120 instead of 0912/0913/0915), which can push claims into manual review, incorrect grouping, or CO-96 medical-necessity denials.
• Leaving patient status as "still a patient" on the final claim after discharge from detox or residential treatment, which conflicts with later claims or readmissions and can cause CO-18 duplicate or CO-109 billing error denials.

Behavioral-health facilities depend on the UB-04 for almost all facility-side revenue: residential treatment, inpatient psych, detox, PHP, IOP, and hospital-based intensive outpatient programs. Each level of care is commonly mapped to specific Type of Bill and revenue code patterns, and payers watch those tightly. If your UB-04 does not match how a payer classifies the service, the claim often goes straight to denial instead of payment.

Carve-out behavioral-health plans create extra UB-04 friction. A client might have medical benefits with one payer and behavioral-health benefits administered by another. The UB-04 has to carry the behavioral-health payer and subscriber data that match the carve-out vendor, plus the correct authorization number. If your front desk or intake staff picks the wrong payer or miskeys the auth into the UB-04, the claim can deny for no coverage or no auth even when benefits are valid.

Concurrent authorization adds another layer. For long per-diem stays, state Medicaid and Medicaid MCOs often approve in short blocks. Statement dates and occurrence span codes on the UB-04 must line up with each auth period. When they do not, everything after the last approved day often denies as CO-197. Cleaning this up means split claims, corrected Type of Bill codes, and careful rebilling.

State Medicaid programs frequently have state-specific UB-04 rules for behavioral health. Examples include mandatory value codes to report number of therapy hours in PHP, special condition codes for court-ordered services, or exact revenue code and HCPCS pairings. Missing these on the UB-04 does not just slow payment. It can trigger repeated CO-16 or N130 denials and put your facility on the radar for focused payment reviews and audits.

AI can help your team treat the UB-04 as a structured data problem instead of a form-filling headache. An agent can pull admission, discharge, and auth data from your EHR, then generate and validate UB-04 fields for each payer: Type of Bill, statement dates, revenue codes, occurrence spans, and covered days. It can also compare each UB-04 against payer rules and historical denial patterns to flag likely problems before you submit.

Supabill's claims-scrubbing agent holds payer- and state-specific UB-04 rules in memory, reads each 837I or UB-04 image, and links it to 835 remittances and CARC/RARC codes. The agent can spot patterns like "PHP claims to this Medicaid MCO deny when value code is missing" or "residential claims over 14 days need split billing". A human still owns judgment calls: deciding how to split a long stay across multiple claims, how to respond to policy-driven CO-50 or CO-97 denials, and when to escalate to payer reps. AI carries the repetitive checks, but your team keeps clinical context, appeals strategy, and payer relationship management.

What is the difference between the UB-04 and the CMS-1500 for behavioral-health billing?

The UB-04 (CMS-1450) is used for institutional or facility claims such as residential treatment, inpatient psych, PHP, IOP, and hospital-based outpatient programs. It reports stay-level information like type of bill, statement dates, revenue codes, and covered days. The CMS-1500 is used for professional claims and focuses on individual providers, CPT/HCPCS codes, and units. In many behavioral-health settings, the facility bills per-diem services on a UB-04 while psychiatrists, psychologists, and therapists bill their professional services on CMS-1500 forms or 837P claims. Source

When should a behavioral-health program bill on a UB-04 instead of a CMS-1500?

Use a UB-04 when billing as a facility for levels of care that are treated as institutional services by the payer, such as inpatient psych, residential treatment, detox, PHP, and IOP. Most Medicaid programs and many commercial plans require these to be billed on a UB-04 or 837I, with specific Type of Bill and revenue code requirements. The CMS-1500 is reserved for office-based therapy, psychiatry visits, and other professional services, even when the clinician is employed by the same organization. Source

Do I still need to care about the paper UB-04 if we only submit electronic 837I claims?

Yes. Even if your clearinghouse submits only 837I transactions, your billing system usually generates a UB-04 layout as the human-readable view of the claim. Payer rules and CMS instructions are written against the UB-04 fields, and remittance denials often reference those fields. When you troubleshoot denials or train staff, you are usually mapping from the UB-04 layout to your system fields and the 837I segments behind them. Source

How does concurrent authorization affect how I fill out the UB-04 for PHP or IOP?

Concurrent authorization means the payer approves only a limited block of days or units at a time. On the UB-04, the Statement From/Through dates and occurrence span codes must align with those approved periods, and the number of covered units or days should not run past the last authorized day. If the billing period crosses an auth boundary, you often need separate claims: one per auth span. When the dates extend beyond the auth, units after the last approved day commonly deny as CO-197 or N130 on the remit. Source

Where can I find official UB-04 billing instructions for Medicare claims?

Medicare UB-04 billing instructions are published in the Medicare Claims Processing Manual, particularly the general instructions and institutional chapters. These manuals explain how to complete each field, including type of bill, occurrence and value codes, patient status, and service lines. Your MAC may also publish local UB-04 billing guidance and training materials on its website, which supplement the national CMS rules. Source

• CMS, CMS Forms
• CMS, Manuals
• Medicaid.gov, Medicaid and CHIP basics