UB04 Patient's Reason for Visit Code Code ICD-10-CM: The field requires a valid ICD-10-CM diagnosis code representing the patient's reason for visit at the time of outpatient registration.

Overview

The Patient’s Reason for Visit Code on the UB-04 (Field 70) is a required ICD‑10‑CM diagnosis code that indicates the patient’s chief complaint or reason for seeking outpatient services at the time of registration. The National Uniform Billing Committee (NUBC) maintains the approved coding sets for the UB‑04 form, and Medicare requires that providers use valid ICD‑10‑CM codes in this field ^[1]. The field is part of the institutional claim data set that Medicare Administrative Contractors must capture for audit trail purposes ^[1]. Although the specific instructions for Field 70 are not detailed in the provided excerpts, the UB‑04 layout includes form locators 66–81, which cover diagnosis and reason‑for‑visit codes ^[1]. Payers such as MassHealth require that all institutional claims be completed in accordance with NUBC standards and that diagnosis codes be reported accurately for claim adjudication ^[2].

When to Use

Field 70 should be used on all outpatient UB‑04 claims where the patient presents for a scheduled or unscheduled visit. It is distinct from the principal diagnosis code (Field 67) because it captures the patient’s stated reason for the visit, which may differ from the final diagnosis after evaluation. The code must be a valid ICD‑10‑CM code from the current code set ^[1]. For Medicare, this field is required when the claim type is outpatient (Type of Bill 13X, 14X, 85X, etc.) and the patient is registered for a visit. MassHealth also requires completion of all diagnosis code fields, including the reason‑for‑visit code, on paper claims submitted to the agency ^[2]. The field is not typically used on inpatient claims, where the principal diagnosis field alone suffices. Providers should verify payer‑specific guidance, as some commercial payers may have different rules for this field.

Step-by-Step Claim Example

A patient arrives for an outpatient clinic visit complaining of “chest pain.” The registration staff enters the appropriate ICD‑10‑CM code for chest pain (e.g., R07.9) in Field 70. The claim is submitted on a UB‑04 with Type of Bill 131 (Hospital Outpatient). The following steps illustrate a typical workflow:

1. Verify patient demographics and insurance – Confirm the patient’s identity and coverage.
2. Record the patient’s stated reason – Ask for the chief complaint and document it.
3. Assign the ICD‑10‑CM code – Use the current code for the symptom or condition described (e.g., R07.9 for chest pain).
4. Place the code in Field 70 – Enter the code left‑justified; no decimals or spaces.
5. Complete remaining diagnosis fields – Field 67 (principal diagnosis) and Fields 68–69 (other diagnoses) as applicable.
6. Review all required data – Ensure admission date (FL12), point of origin (FL15), and discharge status (FL17) are correct per payer rules ^[1].
7. Submit the claim – If paper, mail to the appropriate A/B MAC or managed care plan; otherwise, submit electronically ^[2].

After the visit, if the final diagnosis differs (e.g., acute coronary syndrome, I24.0), that code goes in Field 67, while Field 70 retains the original reason‑for‑visit code.

Common Mistakes & Audit Red Flags

• Using a code that is not a valid ICD‑10‑CM code – The code must be active in the current code set. Invalid codes will cause claim rejection.
• Confusing the reason‑for‑visit code with the principal diagnosis – Field 70 must reflect the patient’s complaint at registration, not the final diagnosis after work‑up.
• Omitting the field entirely – Many payers require this field for outpatient claims; leaving it blank may result in a delayed or denied claim.
• Entering a code for a symptom that is not the actual reason – For example, using “abnormal lab finding” when the patient came in for “shortness of breath.” The code must match the patient’s statement.
• Incorrect formatting – Do not insert decimal points, extra spaces, or leading zeros beyond the code structure (e.g., “R07.9” is correct; “R07.9 ” with trailing space is not). The UB‑04 expects a fixed‑length field; consult payer specifications.
• Using a code from an older ICD‑10‑CM update – Code sets are updated annually (October 1). Using an outdated code is a frequent audit finding.
• Inconsistency with the medical record – The documented chief complaint must support the code submitted. Auditors will compare the code to the clinical note.

Related Codes/Fields

The following table lists key UB‑04 form locators associated with diagnosis and reason‑for‑visit coding.

Field / Code	Description	Source
FL67	Principal Diagnosis Code – ICD‑10‑CM	[1]
FL68	Other Diagnosis Code – ICD‑10‑CM	[1]
FL69	Other Diagnosis Code – ICD‑10‑CM	[1]
FL70	Patient’s Reason for Visit Code – ICD‑10‑CM	[1] (layout includes FL66–81)
FL71	Patient’s Reason for Visit Code – ICD‑10‑CM (second)	[1]
FL72	External Cause of Injury Code – ICD‑10‑CM	[1]
FL04	Type of Bill (e.g., 131 for outpatient)	[1]
FL12	Admission/Start of Care Date	[1]
FL15	Point of Origin for Admission or Visit	[1]
FL17	Patient Discharge Status	[1]
FL18–28	Condition Codes	[1]

Note: Exact field numbers and descriptions for diagnosis codes are maintained by the NUBC and also appear in Medicare instructions for Form CMS‑1450 (UB‑04) ^[1]. MassHealth requires adherence to these same NUBC standards ^[2].

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References

[1] CMS Chapter 25 — https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c25.pdf

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