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UB-04 Form Instructions, Field by Field

What goes in every UB-04 form locator, which fields Medicare requires, and how to avoid the errors that get institutional claims denied.

Quick answer: The UB-04 (CMS-1450) has 81 boxes called form locators (FL). The ones that cause the most denials are the type of bill (FL 4), revenue codes (FL 42), HCPCS codes and units (FL 44 and 46), the principal diagnosis (FL 67) and the NPI (FL 56). The table below shows what goes in each one and whether Medicare requires it.

Patient and bill information (FL 1 to 17)

FL	Field	What to enter	Medicare
1	Billing provider name, address and phone	Your facility's name, street address, city, state, ZIP and phone	Required
2	Pay-to name and address	Only if payments go somewhere else	Not required
3a	Patient control number	Your account number for this patient or visit	Required
3b	Medical record number	The patient's chart number	Situational
4	Type of bill	Four digits: a leading 0, facility type, type of care, and frequency (for example 0131)	Required
5	Federal tax number	Your EIN, format NN-NNNNNNN	Required
6	Statement covers period	First and last dates on this bill	Required
7	Unlabeled	Leave blank	Not used
8	Patient name and ID	Last name, first name, middle initial	Required
9	Patient address	Full mailing address	Required
10	Birth date	MMDDCCYY	Required
11	Sex	M or F	Required
12	Admission or start of care date	Date of admission	Inpatient and home health
13	Admission hour	Hour of admission	Not required
14	Priority (type) of admission or visit	For example 1 emergency, 2 urgent, 3 elective	Required
15	Point of origin	Where the patient came from, such as a physician referral	Required (except bill type 014x)
16	Discharge hour	Hour of discharge	Not required
17	Patient discharge status	Status on the through date, for example 01 home	Required

Codes and dates (FL 18 to 41)

FL	Field	What to enter	Medicare
18-28	Condition codes	Codes for conditions or events that affect this bill	Situational
29	Accident state	State where an accident happened	Not used by Medicare
30	Unlabeled	Leave blank	Not used
31-34	Occurrence codes and dates	Events such as an accident date or a benefits exhausted date	Situational
35-36	Occurrence span codes and dates	Events with a start and end date	Required for inpatient
37	Unlabeled	Leave blank	Not used
38	Responsible party name and address	Used when another payer pays before Medicare	Not required
39-41	Value codes and amounts	Codes with a dollar or unit amount the payer needs	Required

Charges (FL 42 to 49)

FL	Field	What to enter	Medicare
42	Revenue codes	Four-digit code for each charge line; 0001 on the total line	Required
43	Revenue description	Short description for each revenue code	Not required
44	HCPCS, rates or HIPPS codes	CPT/HCPCS code and modifiers for outpatient lines; room rate for inpatient	Required
45	Service date	Date of each outpatient line	Required for outpatient
46	Units of service	Days, visits or the number of times a HCPCS service was done	Required
47	Total charges	Charge for each line, and the total on the 0001 line	Required
48	Non-covered charges	Charges the payer does not cover	Required when any apply
49	Unlabeled	Leave blank	Not used

Payer and insured (FL 50 to 65)

FL	Field	What to enter	Medicare
50	Payer name	Primary payer on line A, others on B and C	A required; B and C situational
51	Health plan ID	The payer's plan ID or the number Medicare assigned	A required; B and C situational
52	Release of information	Whether you have the patient's signature on file to release information	Required
53	Assignment of benefits	Whether the patient assigned benefits to you	Not used by Medicare
54	Prior payments	Amounts already paid by this payer	Situational
55	Estimated amount due from patient	What the patient is expected to owe	Not required
56	Billing provider NPI	Your 10-digit NPI	Required
57	Other provider ID	Legacy IDs	Not used by Medicare
58	Insured's name	Name of the person who holds the coverage	Required
59	Patient's relationship to insured	Code for self, spouse, child and so on	Required
60	Insured's unique ID	Member ID; the MBI for Medicare	Required
61	Insurance group name	Employer plan name	Situational (required if known)
62	Insurance group number	Employer plan group number	Situational (required if known)
63	Treatment authorization code	Prior authorization or referral number	Situational
64	Document control number	The payer's original claim number, on replacement (xx7) or void (xx8) bills	Situational
65	Employer name	Insured's employer, for workers' comp or employer plans	Situational

Diagnoses, procedures and providers (FL 66 to 81)

FL	Field	What to enter	Medicare
66	Diagnosis code qualifier	0 for ICD-10	Required
67	Principal diagnosis and POA	Principal ICD-10-CM code; 67A to 67Q hold up to 17 more; POA indicator on inpatient claims	Required
68	Reserved	Leave blank	Not used
69	Admitting diagnosis	Condition that caused the admission	Required for inpatient
70a-c	Patient's reason for visit	Reason for an unscheduled outpatient visit	Situational
71	PPS code	Prospective payment system code	Not used by Medicare
72	External cause of injury codes	Codes for how an injury happened	Not used by Medicare
73	Reserved	Leave blank	Not used
74	Principal procedure code and date	ICD-10-PCS code; 74a to 74e for other procedures	Inpatient, when a procedure was done
75	Reserved	Leave blank	Not used
76	Attending provider	Name and NPI of the provider responsible for the patient's care	Required for most claims
77	Operating provider	Name and NPI of the surgeon	When a surgical procedure is billed
78-79	Other providers	Name and NPI of others, such as the referring provider	Situational
80	Remarks	Extra information the payer needs	Situational
81	Code-code field	Extra codes, such as a taxonomy code with qualifier B3	Situational

The Fields That Cause the Most Denials

FL 4: Type of bill

Four digits. The first is a 0, which Medicare ignores. The second is the type of facility (1 hospital, 2 skilled nursing, 3 home health, 7 clinic, 8 special facility). The third is the type of care (1 inpatient, 3 outpatient). The fourth is the frequency: 1 for a complete claim, 7 to replace a claim, 8 to void it. A wrong type of bill sends the claim down the wrong payment path.

FL 42 to 47: Revenue code lines

Each charge line needs a revenue code (FL 42). Outpatient lines also need the HCPCS code and modifiers (FL 44), the date (FL 45), the units (FL 46) and the charge (FL 47). Put revenue code 0001 on the total line. Units must match what the HCPCS code describes, so check them against the MUE limits.

FL 67: Diagnoses and POA

Enter the principal diagnosis first, without the decimal point. On inpatient claims, add a present on admission indicator to each diagnosis: Y (yes), N (no), U (not documented) or W (cannot be determined). Check codes with our ICD-10 code lookup.

FL 56 and 76: NPIs

FL 56 is the facility's billing NPI. FL 76 is the attending provider's NPI, and FL 77 the surgeon's. A typo in any of them rejects the claim.

UB-04 vs CMS-1500

	UB-04 (CMS-1450)	CMS-1500
Who uses it	Hospitals, SNFs, home health, hospice, dialysis, some clinics	Physicians, therapists, suppliers, ambulatory providers
Electronic version	837I	837P
Main codes	Revenue codes, type of bill, HCPCS, ICD-10-CM and ICD-10-PCS	CPT/HCPCS, place of service, ICD-10-CM
Original claim number	FL 64	Box 22

Billing professional claims too? See our CMS-1500 instructions and check them with our CMS-1500 claim checker.

Sources: CMS Medicare Claims Processing Manual, Pub. 100-04, Chapter 25, Completing and Processing the Form CMS-1450 Data Set (section 75, form locators 1 to 81). Code lists for condition, occurrence, value, revenue and discharge status codes come from the NUBC Official UB-04 Data Specifications Manual.

Frequently Asked Questions

What is a UB-04 form?

The UB-04, also called the CMS-1450, is the claim form institutional providers use: hospitals, skilled nursing facilities, home health agencies, hospices, dialysis centers and some clinics. Its electronic version is the 837I. Doctors and other professionals use the CMS-1500 instead.

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

The UB-04 bills a facility's charges using revenue codes, a type of bill and inpatient details such as admission and discharge status. The CMS-1500 bills a professional's services using CPT codes and place of service codes. A hospital stay often produces both: a UB-04 from the hospital and a CMS-1500 from each doctor.

What does type of bill 0131 mean?

Hospital (1), outpatient (3), admit through discharge claim (1). The last digit is the frequency code: 7 replaces an earlier claim and 8 voids it, and both need the original claim number in FL 64.

Where does the original claim number go on a UB-04?

In FL 64, the document control number. Use it with a type of bill ending in 7 (replacement) or 8 (void).

How many diagnosis codes fit on a UB-04?

FL 67 holds the principal diagnosis and 67A to 67Q hold up to 17 more. Inpatient claims also need a present on admission indicator for each one.

Reviewed by Hassan Raza Awan, Founder — 4+ years of hands-on U.S. medical billing experience. General billing information — verify against current CMS guidance and your payer contracts.

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