UB04 Field 4: Type of Bill

Field 4, “Type of Bill,” is a four‑digit alphanumeric code found on the UB‑04 claim form. The code is structured as follows: the first digit is a leading zero that is ignored by CMS; the second digit identifies the type of facility; the third digit specifies the type of care; and the fourth digit indicates the sequence or frequency of the bill ^[1]. This field provides the facility type, care type, and billing frequency necessary for processing the claim.mass.gov/doc/ub-04-billing-guide-0/download). Understanding the structure of the Type of Bill code helps ensure accurate claim submission and reduces the risk of denials.

When to Use

Field 4 must be included on every UB‑04 claim, whether the service is inpatient or outpatient. The code provides three critical pieces of information that payers use to process the claim. The second digit (facility type) indicates the setting where services were rendered—for example, “1” for a hospital, “2” for a skilled nursing facility, or “7” for a clinic or hospital‑based ESRD facility ^[1]. The third digit (type of care) describes the nature of the services, such as “1” for inpatient Part A, “3” for outpatient services, or “6” for intermediate care level II ^[1]. The fourth digit (frequency) communicates the billing cycle—for instance, “1” for a claim covering the entire stay (admit through discharge), “2” for an interim first claim, or “7” for a replacement of a prior claim ^[1]. Providers must select the correct combination based on the specific episode of care and the billing period. The MassHealth guide confirms that the UB‑04 is used by acute hospitals and other institutional providers, and Field 4 is a mandatory element in completing the form ^[2]. Failure to populate this field correctly can lead to claim rejection or payment delays.

Step‑by‑Step Claim Example

Consider a patient admitted to a general acute care hospital for a three‑day inpatient stay, and the hospital is submitting a single claim for the entire stay. The correct Type of Bill code would be “0111.” The leading zero is the first digit. The second digit “1” denotes a hospital facility. The third digit “1” indicates inpatient Part A care. The fourth digit “1” signifies “Admit Through Discharge” (the full stay) ^[1]. If the same hospital provides an outpatient service, such as a clinic visit, the code would change. For a hospital‑based outpatient encounter, the facility digit remains “1,” but the care digit becomes “3” (outpatient). If this is the first and only claim for the encounter, the frequency digit would be “1” again, yielding “0131” ^[1]. For an interim‑first claim on an inpatient stay, the fourth digit would be “2.” If the claim is replacing a previously submitted incorrect claim, the fourth digit changes to “7” ^[1]. After selecting the code, the provider enters it in Box 4 of the UB‑04 form. The MassHealth guide requires that the UB‑04 be completed accurately for all acute inpatient and outpatient claims, and Field 4 is a critical part of that process ^[2]. This example demonstrates how each digit works together to describe the episode and billing status.

Common Mistakes & Audit Red Flags

One frequent error is using an incorrect facility type digit. For instance, billing a hospital outpatient service with a facility digit of “2” (skilled nursing facility) can cause a denial. Another mistake is misapplying the frequency digit. Using “1” (admit through discharge) on an interim‑last claim would be incorrect because the final claim for a stay should use “4” ^[1]. Providers sometimes omit the leading zero or pad it with other characters, but the leading zero must be present and is ignored by CMS ^[1]. Using an obsolete code, such as the discontinued “5” for religious nonmedical extended care (discontinued 10/1/05), is a compliance red flag ^[1]. Additionally, selecting the wrong care digit for clinic services—for example, using “3” (outpatient) when “4” (other Part B) is required—can lead to audit scrutiny. The MassHealth guidance emphasizes that all claims must be accurate and complete, and incorrect Type of Bill codes are a common reason for claim rejections ^[2]. Providers should also avoid using reserved codes (e.g., “9” for certain digits) without specific authorization, as this can trigger manual review.

Related Codes/Fields

The Type of Bill code interacts with several other fields on the UB‑04. The following table lists the digit positions and their corresponding code sets, which are defined in the Noridian source. These code sets are directly tied to Field 4 and must be used consistently with other claim elements.

Digit Position	Code Set Description	Examples of Valid Codes (from Noridian)
2nd Digit	Type of Facility	1 – Hospital, 2 – SNF, 3 – Home Health, 4 – Religious Nonmedical (Hospital), 6 – Intermediate Care, 7 – Clinic or Hospital‑based ESRD, 8 – Special Facility (CAH, ASC)
3rd Digit	Type of Care	1 – Inpatient Part A, 2 – Inpatient Part B, 3 – Outpatient, 4 – Other Part B, 5 – Intermediate Care Level I, 6 – Intermediate Care Level II, 7 – Subacute/Swing Beds, 8 – NA/Reserved
4th Digit	Frequency / Sequence	0 – Nonpayment, 1 – Admit Through Discharge, 2 – Interim First, 3 – Interim Continuing, 4 – Interim Last, 5 – Late Charge, 7 – Replacement, 8 – Void/Cancel, 9 – Final for HHA PPS, A through Z for various adjustments/encounters

Source for all codes: ^[1]

The MassHealth UB‑04 guide indicates that Field 4 is part of a larger set of required fields on the form, including patient information, revenue codes, and diagnosis codes, which must be completed in accordance with the payer’s instructions ^[2]. Accurate coding of the Type of Bill helps ensure that the correct revenue codes and rate calculations are applied.

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References

[1] Noridian Bill Types — https://med.noridianmedicare.com/web/jea/topics/claim-submission/bill-types

[2] MassHealth UB-04 Guide — https://www.mass.gov/doc/ub-04-billing-guide-0/download