UB04 Diagnosis/Procedure Code Qualifier Code 9: ICD-9-CM

Overview

This qualifier is part of the National Uniform Billing Committee (NUBC) approved coding maintained for the UB-04 form, which is also known as Form CMS-1450 for Medicare billing ^[1]. The UB-04 is a uniform institutional provider bill suitable for billing multiple third-party payers, and each payer may have specific requirements for which code sets are accepted ^[1]. For Medicare, the A/B MACs (A) and (HHH) must be able to capture all NUBC-approved input data for audit trail purposes ^[1]. Providers must ensure that the code set used matches the qualifier code reported to avoid claim rejection or audit findings.

When to Use

Use code 9 in Field 66 when the diagnosis and/or procedure codes reported on the UB-04 claim form are based on the ICD-9-CM coding system. This applies primarily to:

• Historical claims for services provided before October 1, 2015, when ICD-9-CM was the standard coding system.
• Adjustment or replacement claims for original claims that were submitted with ICD-9-CM codes.
• Certain payer-specific requirements where a payer (such as some state Medicaid programs or commercial insurers) may still accept ICD-9-CM codes for specific legacy billing scenarios.

For Medicare, the instructions for completing Form CMS-1450 apply to both inpatient and outpatient claims unless otherwise noted, and the A/B MAC does not need to obtain data not needed to process the claim ^[1]. If you are submitting a claim for services rendered after October 1, 2015, you should use code 0 (ICD-10-CM) instead of code 9, unless a specific payer exception applies. Always verify payer-specific requirements, as some payers may reject claims with ICD-9-CM codes after the transition date.

Step-by-Step Claim Example

Scenario: A hospital is submitting a paper UB-04 claim for an inpatient stay that occurred in September 2015, before the ICD-10 transition. The primary diagnosis is 414.01 (Coronary atherosclerosis of native coronary artery), and the principal procedure is 36.11 (Aortocoronary bypass of one coronary artery).

Step 1: Complete the header information. Enter the billing provider name, address, and NPI in Field 1. Enter the patient's name and identifier in Field 8. Enter the statement covers period (From/Through) in Field 6, e.g., 09/15/2015 – 09/20/2015.

Step 2: Enter diagnosis codes. In Field 67 (Principal Diagnosis Code), enter 41401 (the ICD-9-CM code without the decimal). In Field 68 (Other Diagnosis Codes), enter any additional ICD-9-CM diagnosis codes, such as 4019 (Essential hypertension, unspecified) and 25000 (Diabetes mellitus without mention of complication, type II or unspecified type, not stated as uncontrolled).

Step 3: Enter procedure codes. In Field 74 (Principal Procedure Code/Date), enter 3611 (the ICD-9-CM procedure code without the decimal) and the date of the procedure, e.g., 09/16/2015.

Step 4: Enter the qualifier code. In Field 66 (Diagnosis/Procedure Code Qualifier), enter 9 to indicate that all diagnosis and procedure codes on the claim are ICD-9-CM codes.

Step 5: Complete remaining fields. Fill in Fields 1-81 as required by the payer. For Medicare, follow the instructions in CMS Chapter 25 for each form locator ^[1]. For MassHealth, follow the UB-04 Billing Guide instructions ^[2].

Step 6: Submit the claim. Send the completed UB-04 to the appropriate payer. For Medicare, submit to the A/B MAC (A) or (HHH) ^[1]. For MassHealth, submit electronically unless an approved waiver is in place ^[2].

Common Mistakes & Audit Red Flags

1. Using code 9 for post-ICD-10 claims. The most common error is using code 9 for services provided after October 1, 2015. This will likely result in claim rejection or denial. Always use code 0 (ICD-10-CM) for services on or after that date.

2. Mixing ICD-9-CM and ICD-10-CM codes on the same claim. The qualifier code 9 applies to all diagnosis and procedure codes on the claim. If you mix code sets, the claim will be rejected. Ensure all codes are from the same coding system.

3. Omitting the qualifier code entirely. Field 66 is required for proper claim processing. Leaving it blank may cause the claim to be returned or delayed. The A/B MAC must be able to capture all NUBC-approved input data for audit trail purposes ^[1].

4. Using incorrect code format. ICD-9-CM codes should be entered without decimals (e.g., 41401, not 414.01). Entering decimals or extra characters can cause processing errors.

5. Failing to update for adjustment claims. When submitting an adjustment to a claim originally filed with ICD-9-CM codes, ensure the qualifier code 9 is still appropriate. If the adjustment involves new services after the ICD-10 transition, you may need to use code 0 instead.

6. Not verifying payer-specific requirements. Some payers, including MassHealth, may have specific rules about which code sets are accepted. Always check the payer's billing guide ^[2].

Related Codes/Fields

Code/Field	Description	Source
0	ICD-10-CM (current standard for diagnosis codes)	[1]
1	ICD-10-PCS (current standard for inpatient procedure codes)	[1]
2	CPT-4 (Current Procedural Terminology, 4th Edition)	[1]
3	HCPCS (Healthcare Common Procedure Coding System)	[1]
4	CDT (Code on Dental Procedures and Nomenclature)	[1]
Field 67	Principal Diagnosis Code	[1]
Field 74	Principal Procedure Code/Date	[1]
Field 66	Diagnosis/Procedure Code Qualifier (where code 9 is entered)	[1]

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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