UB04 Field 74: Principal Procedure Code/Date

Overview

Field 74 on the UB‑04 claim form captures the Principal Procedure Code and Date for inpatient services. According to CMS Chapter 25, this field is situational and “required on inpatient claims when a procedure was performed. Not used on outpatient claims.” ^[1] The Maryland Medicaid UB‑04 instructions list FL 74 as “Principal Procedure Code and Date” without additional detail, but confirm its placement on the form. ^[2] CMS transmittal R1915CP reiterates that FL 74 is situational. ^[3]

When to Use

Field 74 must be completed on inpatient claims when any surgical or therapeutic procedure was performed during the admission. ^[1] If no procedure was performed, the field should be left blank. The field is not used on outpatient claims; outpatient procedure codes are reported in the revenue code lines (FL 42‑49) with HCPCS/CPT codes and dates. ^[1] Maryland Medicaid’s instructions do not modify this requirement, simply listing the field as part of the standard UB‑04 layout. ^[2] CMS R1915CP confirms the situational nature of the field. ^[3] Therefore, providers should only populate FL 74 on inpatient claims where a procedure was performed, and must ensure the code and date are accurate to avoid claim rejections or audit findings.

Step-by-Step Claim Example

Consider an inpatient stay for a patient who underwent a laparoscopic cholecystectomy (ICD‑10‑PCS code 0FT44ZZ) on March 15, 2025. The principal diagnosis is cholelithiasis (K80.20). The claim is being submitted to Medicare Part A.

1. Verify inpatient status – The claim type is 131 (Hospital Inpatient) or 121 (Medicare Part A). Field 74 is only used for inpatient claims. ^[1]
2. Determine principal procedure – The cholecystectomy is the definitive treatment and is the most significant procedure performed. No other procedures were done.
3. Enter the procedure code – In FL 74, enter the ICD‑10‑PCS code 0FT44ZZ. The code qualifier (ICD version indicator) is reported in FL 66. ^[2]
4. Enter the procedure date – In the date portion of FL 74, enter 03152025 (MMDDYYYY format as required by the payer). The date must match the date the procedure was performed.
5. Leave FL 74A‑74E blank – Since no other procedures were performed, the “Other Procedure Code and Date” fields (FL 74A‑74E) are not required. ^[1]
6. Submit the claim – The completed FL 74 ensures the claim reflects the principal procedure. If the field were omitted, the claim might be returned as incomplete or denied for lack of required data.

Common Mistakes & Audit Red Flags

• Using FL 74 on outpatient claims – CMS explicitly states this field is not used on outpatient claims. ^[1] Submitting an outpatient claim with data in FL 74 may cause the field to be ignored or trigger a rejection.
• Omitting the field when a procedure was performed – On inpatient claims, if a procedure was done, FL 74 is required. Leaving it blank can lead to claim suspension or denial. ^[1]
• Incorrect procedure code or date – The code must be a valid ICD‑10‑PCS code for the principal procedure. Using a CPT code or an outdated ICD‑9 code will cause errors. The date must match the actual procedure date; discrepancies are audit red flags.
• Confusing principal with other procedures – Only the most significant procedure should be entered in FL 74. Additional procedures go in FL 74A‑74E. Misplacement can lead to incorrect DRG assignment or payment.
• Ignoring payer‑specific requirements – While CMS and Maryland Medicaid treat FL 74 as situational, some payers may require it even when no procedure is performed (e.g., entering “None”). Always verify payer instructions. ^{[2] [3]}

Related Codes/Fields

The table below lists fields on the UB‑04 that interact with or are related to FL 74.

Field	Description	Relationship to FL 74
FL 66	Diagnosis and Procedure Code Qualifier (ICD Version Indicator)	Indicates the code set used for FL 74 (e.g., ICD‑10‑PCS). [2]
FL 67	Principal Diagnosis Code and POA Indicator	The principal diagnosis should relate to the principal procedure in FL 74.
FL 74A‑74E	Other Procedure Codes and Dates	Used for additional procedures performed during the same inpatient stay. [1]
FL 71	PPS Code	May affect DRG assignment; the principal procedure in FL 74 is a key DRG determinant.
FL 42‑49	Revenue Code Lines (with HCPCS/CPT)	On outpatient claims, procedure information is reported here instead of FL 74. [1]

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References

[1] CMS Chapter 25 — FL 74 — https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c25.pdf

[2] Maryland Medicaid — FL 74 — https://health.maryland.gov/mmcp/provider/Documents/ffs-billing/UB04-Hospital-Billing-Instructions%20%281%29.pdf

[3] CMS R1915CP — https://www.cms.gov/Regulations-and-Guidance/Guidance/Transmittals/downloads/R1915CP.pdf