CurrentHighmark Blue Cross Blue Shield WnyPolicy G-06020

Modifier 91 reimbursement policy

Governs reimbursement for repeat clinical diagnostic laboratory tests billed with Modifier 91 for Highmark BCBS MMC, HARP, and Child Health Plus members; applies to both participating and non-participating professional providers and facilities unless contracts or mandates state otherwise.

Policy Summary

PayerHighmark Blue Cross Blue Shield Wny

PolicyModifier 91 reimbursement policy

Policy CodePolicy G-06020

Change TypeClarified (no material changes)

Effective DateJul 17, 2024

Next Review Date

Key ActionMedical documentation may be requested to support the use of Modifier 91.

SourceLink

POLICY UPDATE CHANGES

Review approved and effective: no changes.

100%reimbursement for tests billed with Modifier 91

MMC, HARP, CHPlusprograms covered

07/17/2024effective date

1denial risk (duplicate)

Modifier 91 Reimbursement Criteria

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Reimbursement is allowed when clinical diagnostic laboratory tests are repeated on the same day and billed with Modifier 91, unless provider, state, federal, or CMS contracts and/or requirements indicate otherwise.

Reimbursement amount: 100% of the applicable fee schedule or contracted/negotiated rate for the clinical diagnostic laboratory test billed with Modifier 91.

Medical documentation may be requested to support the use of Modifier 91. Services must meet authorization and medical necessity guidelines and be supported in the medical record.

ALL of the following

NOT allowed when any of the following apply
- Modifier 91 is used to repeat a test to confirm initial results.
- Modifier 91 is used because there was a problem with the specimen or equipment when performing the initial test.
- Modifier 91 is used when other code(s) describe a series of test results.

Failure to use Modifier 91 appropriately may result in denial of the repeated laboratory test as a duplicate service; standard correct coding applies.

Modifier and Reimbursement Rate

ModifierModifier

Modifier 91

Used to indicate a clinical diagnostic laboratory test was repeated on the same day for the same member to obtain multiple test results.

Reimbursement for Modifier 91

Reimbursement rate100% of the applicable fee schedule or contracted/negotiated rate for tests billed with Modifier 91

ApplicabilityApplies to repeat clinical diagnostic laboratory tests appended with Modifier 91 unless provider, state, federal, or CMS contracts/requirements indicate otherwise

Programs addressedMMC, HARP, Child Health Plus (as referenced in policy scope)

DocumentationMedical documentation may be requested to support the use of Modifier 91

Policy effective date07/17/2024 (review approved; no changes)

Documentation, Authorization, and Claims Submission

Documentation Required

Documentation may be requested to support Modifier 91

Medical documentation may be requested to support the use of Modifier 91. Ensure supporting records are available in the medical record to justify the repeat clinical diagnostic laboratory test billed with Modifier 91.

Denial Risk

Meet authorization, medical necessity, and billing requirements

Services must meet authorization and medical necessity guidelines and be billed with industry-standard, compliant codes; failure to follow billing or submission guidelines may result in claim rejection, denial, recovery, or adjustment of reimbursement.

Use CPT, HCPCS, and/or revenue codes that fully reflect services performed and are supported in the medical record.
Failure to use Modifier 91 appropriately (e.g., when only a single test result is required) may result in denial as a duplicate service.

Modifier 91 Definition and Restrictions

Modifier 91 — Definition

DefinitionModifier 91: Used to indicate a clinical diagnostic laboratory test was repeated on the same day for the same member to obtain multiple test results.

Scope of useApplies specifically to repeat clinical diagnostic laboratory tests performed the same day for the same member

Coding contextListed under Modifier code group in policy coding section

Modifier 91 — Restrictions

Primary restrictionModifier 91 may not be used to repeat a test to confirm initial results (inappropriate use may result in denial as a duplicate service)

Specimen/equipment issuesMay not be used when the repeat is due to a problem with the specimen or equipment for the initial test

Series of test resultsMay not be used when other codes describe a series of test results

ConsequencesFailure to use the modifier appropriately may result in denial, recovery, or adjustment of reimbursement per standard correct coding and authorization rules