CurrentPremera BluecrossPolicy N/A

Modifier 90 — Reference (Outside) Laboratory billing and reimbursement

Governance of reimbursement for laboratory tests billed with modifier 90 (reference/outside laboratory), specifying who may bill and when tests are reimbursed across Premera Blue Cross lines of business and affiliated entities.

Policy Summary

PayerPremera Bluecross

PolicyModifier 90 — Reference (Outside) Laboratory billing and reimbursement

Policy CodePolicy N/A

Change TypeMaterial and clarified updates

Effective DateN/A

Next Review DateN/A

Key ActionThe independent reference laboratory that analyzed the laboratory test must bill the Plan directly and append modifier 90; only one laboratory may bill for a referred laboratory service.

SourceLink

POLICY UPDATE CHANGES

Added statement that only one laboratory may bill for a referred laboratory service.

Created new 'Codes and Coding Guidelines' section with drawing fee procedure code(s).

Policy clarified to include facility claims in addition to professional claims for application of modifier 90.

1drawing fee procedure code listed (36415)

All linesApplies to

1Single lab may bill

MultipleAnnual review listed

Coverage Criteria for Modifier 90 Services

Coverage criteria for modifier 90 billed laboratory services

Covered when ALL of the following are met:

Coverage is limited to tests performed by and billed by the independent reference laboratory that analyzed the laboratory test; the independent reference laboratory must bill the Plan directly and append modifier 90.

Only one laboratory may bill for a referred laboratory service.

Tests billed with modifier 90 will not be reimbursed when billed by a party other than the independent reference laboratory that analyzed the test (applies to professional and facility claims).

Modifier 90 is not valid on drawing fee procedure codes such as 36415 (collection of venous blood by venipuncture).

Codes and Coding Guidelines

Policy Summary

PayerPremera Bluecross

PolicyModifier 90 — Reference (Outside) Laboratory billing and reimbursement

Policy CodePolicy N/A

Change TypeMaterial and clarified updates

Effective DateN/A

Next Review DateN/A

Key ActionThe independent reference laboratory that analyzed the laboratory test must bill the Plan directly and append modifier 90; only one laboratory may bill for a referred laboratory service.

SourceLink

On This Page

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.

Billing and Provider Requirements

Billing Rule

Require reference lab to bill with modifier 90; only one lab may bill

The independent reference laboratory that analyzed the laboratory test must bill the Plan directly and append modifier 90. Only one laboratory may bill for a referred laboratory service; the Plan does not reimburse laboratory tests appended with modifier 90 that are billed by a party other than the independent reference laboratory that analyzed the test. If the reference laboratory is not participating with the Plan, member financial liability may increase for services not ordered by a treating provider.

Modifier 90 must be appended by the independent reference laboratory that performed the analysis when submitting claims (professional or facility).
Only one laboratory may bill for a referred laboratory service — duplicate billing by another party will not be reimbursed.
Non‑participating laboratory claim submissions can result in increased member financial liability.

Definitions

Modifier 90 definition — Reference (Outside) Laboratory

DefinitionModifier 90 — Reference (Outside) Laboratory indicates that a third‑party clinical reference laboratory performed the laboratory test analysis rather than the ordering provider.

Billing requirementThe independent reference laboratory that analyzed the laboratory test must bill the Plan directly and append modifier 90.

Single‑biller ruleOnly one laboratory may bill for a referred laboratory service.

Facility and professional claimsPolicy applies to tests billed on professional claims and on facility claims; modifier 90 reimbursement rules cover both claim types.

Effect of non‑participating labsIf the reference laboratory is non‑participating, claim submissions may increase member financial liability for services not ordered by the treating provider.

Drawing fee procedure code definition

DefinitionDrawing fee procedure codes are procedure codes for specimen collection (example: CPT 36415, collection of venous blood by venipuncture).

Modifier 90 applicabilityModifier 90 is not valid on drawing fee procedure codes (e.g., 36415).

Coding status36415 is listed specifically as a drawing fee procedure code in the policy's Codes and Coding Guidelines.