Medical Billing • CPT Modifiers • Surgery

Modifier 66

Modifier 66 = Surgical Team. Learn what Modifier 66 means, when it may be reported, how it differs from Modifier 62, what documentation is required, how Medicare evaluates team surgery and how AR callers can handle Modifier 66 denials.

Start Learning Quick Cheat Sheet

Surgical Team

Modifier 66 at a Glance

The essential concepts every biller, coder and AR caller should understand.

Surgical Team

Modifier 66 identifies qualifying services performed by a surgical team.

Team Concept

Medicare describes team surgery as involving more than two surgeons of different specialties for a specific procedure.

DOC

Documentation

Documentation must support the medical necessity of the surgical team.

PBR

By Report

Medicare requires sufficient information to allow pricing by report for team-surgeon claims.

What Is Modifier 66?

Start with the basic definition.

Simple Definition

Modifier 66 indicates that a surgical procedure required the services of a surgical team.

For Medicare, the team-surgeon concept applies when more than two surgeons of different specialties are required to perform a specific procedure.

Each surgeon who is appropriately participating as a member of the surgical team reports the applicable procedure with Modifier 66 when the requirements are met.

Easy Way to Remember Modifier 66

Think:

“66 = A true surgical team is required.”

It is not simply a situation where multiple physicians happen to participate in the same patient’s care.

What Does a Surgical Team Look Like?

A team involves multiple surgeons working together on a qualifying procedure.

SURGEON
1

SURGEON
2

SURGEON
3

ADDITIONAL
TEAM

Important

Simply having several physicians involved in a patient’s treatment does not automatically make the service a Modifier 66 surgical-team service.

The procedure must qualify and the medical record must support the necessity for the surgical team.

When May Modifier 66 Be Appropriate?

Complex Procedure

The procedure is sufficiently complex to require a surgical team.

Multiple Surgeons

More than two surgeons of different specialties are required under Medicare’s team-surgery concept.

Medical Necessity

Documentation supports why a surgical team was medically necessary.

Qualifying CPT

The procedure is eligible for team-surgeon reporting under the applicable fee schedule and coding rules.

Team Participation

The reporting surgeon actually participated as part of the qualifying surgical team.

Complete Documentation

The claim can be supported with sufficient information for payer review and pricing.

Important: Modifier 66 Is Not for Two Surgeons

For Medicare, Modifier 66 is not the appropriate modifier simply because two surgeons participate in the same procedure.

When two surgeons of different specialties are required to perform a specific procedure, Medicare’s Claims Processing Manual identifies Modifier 62 for co-surgery.

Modifier 66 is associated with a surgical team involving more than two surgeons of different specialties when the requirements are met.

Modifier 62 vs Modifier 66

One of the most important modifier distinctions in surgical billing.

Feature	Modifier 62	Modifier 66
Basic Concept	Co-surgeons	Surgical team
Medicare Team Size	Two surgeons	More than two surgeons of different specialties
Same Procedure	Yes, under applicable co-surgery rules	Yes, when the procedure qualifies for team surgery
Medical Necessity	May require supporting documentation depending on the Medicare indicator	Documentation must support the medical necessity of the surgical team
Payment	Subject to applicable co-surgery rules	Subject to team-surgery indicators and review
Key Memory	62 = Two surgeons	66 = Surgical team

Modifier 66 vs Other Surgical Modifiers

Co-Surgeons

Used when two surgeons of different specialties are required for the same procedure under applicable rules.

Surgical Team

Used for qualifying team-surgery circumstances involving more than two surgeons of different specialties under Medicare’s team-surgery concept.

Assistant Surgeon

Identifies an assistant surgeon rather than a surgical team.

Minimum Assistant Surgeon

Used for an assistant surgeon when minimum assistant-surgeon services are required.

Assistant When Qualified Resident Unavailable

Identifies qualifying assistant-surgeon circumstances involving resident availability.

Not an Assistant Modifier

Modifier 66 represents team-surgery circumstances and should not be substituted for assistant-surgeon modifiers.

How to Bill Modifier 66

General workflow for evaluating a team-surgery claim.

1 Identify the exact CPT procedure performed.

2 Determine whether the procedure is eligible for team-surgery reporting.

3 Identify all surgeons participating in the procedure.

4 Confirm that the circumstances represent a true surgical team.

5 Determine whether more than two surgeons of different specialties were required under Medicare’s applicable rules.

6 Confirm medical necessity for the team.

7 Review the applicable Medicare Physician Fee Schedule indicator.

8 Verify payer-specific requirements.

9 Append Modifier 66 when all applicable requirements are met.

10 Submit supporting documentation and monitor adjudication.

Modifier 66 Documentation Checklist

Procedure

Clearly document the procedure performed.

Team Members

Identify the surgeons who participated in the surgical team.

Specialties

Document the specialties involved when applicable.

Medical Necessity

Explain why the complexity of the procedure required a surgical team.

Operative Report

The operative documentation should support the services and team participation.

Pricing Support

Medicare requires sufficient information on team-surgeon claims to allow pricing by report.

Medicare Team-Surgery Indicators

CMS uses indicators to identify procedures for which Medicare may pay team surgeons.

Team Not Allowed

Medicare does not allow payment for team surgeons for that procedure.

Team Could Be Paid

Team surgeons could be paid, but Medicare requires supporting documentation to establish medical necessity of the team.

Team Allowed

Team surgeons are allowed and payment is made by report under the applicable Medicare rules.

What About Indicator 9?

CMS identifies indicator 9 as meaning the team-surgery concept does not apply.

Modifier 66 Examples

Educational examples. Always verify the specific CPT code, Medicare indicator and payer policy.

Example 1 — Qualifying Surgical Team

A highly complex procedure requires more than two surgeons from different specialties, and the medical record supports the medical necessity of the team.

CPT XXXXX-66

Each participating surgeon appropriately reports the procedure with Modifier 66 when the applicable Medicare and CPT requirements are satisfied.

Example 2 — Two Surgeons

Two surgeons of different specialties are required to perform a procedure.

CPT XXXXX-62

Under Medicare’s general co-surgery rules, this is a Modifier 62 situation rather than Modifier 66.

Example 3 — Three Surgeons, Same Specialty

Three physicians participate, but the circumstances do not establish the required surgical-team criteria.

3 physicians ≠ automatic 66

The number of physicians alone does not establish Modifier 66 eligibility.

Example 4 — Assistant Surgeon

A primary surgeon performs the procedure with an assistant surgeon.

Modifier 80

This is not automatically a Modifier 66 situation.

Example 5 — Procedure Not Eligible

Multiple surgeons participate, but the Medicare team-surgery indicator does not allow payment for team surgeons.

Indicator 0

Modifier 66 should not be used simply because several surgeons were involved.

Example 6 — Documentation Missing

The claim includes Modifier 66, but the medical record does not support why the surgical team was medically necessary.

Documentation Gap

The payer may request records or deny/review the claim.

Common Modifier 66 Denials

Blue-only denial cards matching the rest of your modifier library.

Denial 01

Team Surgery Not Allowed

The procedure is not eligible for Medicare team-surgeon payment.

Denial 02

Team Medical Necessity Not Supported

Documentation does not establish why a surgical team was medically necessary.

Denial 03

Incorrect Modifier

Modifier 66 was used when another modifier, such as 62 or an assistant-surgeon modifier, may apply.

Denial 04

Insufficient Documentation

The claim does not contain enough information for the payer to evaluate or price the service.

Denial 05

Team Criteria Not Met

The circumstances do not establish a qualifying surgical team.

Denial 06

Payer Policy Restriction

The payer may apply additional reimbursement or documentation requirements.

Denial 07

Wrong Medicare Indicator

The procedure’s current team-surgery indicator does not support payment as billed.

Denial 08

Duplicate Team Billing

Multiple claims or claim lines may not correctly reflect the qualifying team-surgery circumstances.

Denial 09

Pricing by Report Required

The payer requires sufficient operative and supporting information before determining reimbursement.

How an AR Caller Should Work a Modifier 66 Denial

Practical denial-management workflow.

Review the EOB / ERA

Identify the exact denial reason, CARC, RARC and affected claim line.

Identify the CPT Code

Determine the exact procedure billed with Modifier 66.

Verify the Medicare Indicator

Check whether the procedure is identified as eligible for team-surgeon payment under the current applicable Medicare fee-schedule indicator.

Review the Team

Determine who participated and whether the circumstances establish a qualifying surgical team.

Verify Specialties

For Medicare, review whether the team involved more than two surgeons of different specialties as required by the applicable rules.

Review Medical Necessity

Confirm that the medical record supports the necessity of a surgical team.

Check Documentation

Review the operative report and other documentation required for team-surgery review and pricing.

Compare Modifier 62 / 66

Determine whether the actual circumstances support co-surgery rather than team surgery.

Correct or Appeal

If incorrectly billed, follow the payer’s corrected-claim process. If properly supported, submit reconsideration or appeal with documentation.

Document Follow-Up

Record payer representative, call reference number, action taken and next follow-up date.

AR Caller Script for Modifier 66

“I’m calling regarding a claim that was denied involving Modifier 66.”

“Could you please provide the exact denial reason and the applicable claim adjustment reason code?”

“Can you confirm whether CPT [CODE] is eligible for team-surgeon reimbursement under your current policy?”

“Can you confirm the current team-surgery indicator for this procedure?”

“Can you confirm whether your policy requires documentation establishing medical necessity for the surgical team?”

“The operative documentation identifies the participating surgeons and their specialties. Can you confirm what documentation is required for reconsideration?”

“Is the denial related to the Modifier 66 itself, the procedure eligibility, the number or specialties of surgeons, or insufficient documentation?”

“If the claim is eligible, may we submit the operative report and supporting documentation for reconsideration?”

“Could you please provide the claim reference number and the appropriate submission method?”

Modifier 66 Appeal Strategy

Identify Denial

Clearly identify the denied CPT line and the payer’s denial reason.

Establish Eligibility

Demonstrate that the procedure is eligible for team-surgeon reporting.

Establish Team

Identify the surgeons and specialties involved.

Establish Necessity

Explain why the complexity of the procedure required a surgical team.

Submit Operative Report

Provide the documentation required by the payer.

Request Reprocessing

Request reconsideration or reprocessing when the claim is correctly supported.

Root Causes of Modifier 66 Denials

Wrong Modifier

Modifier 66 was used when Modifier 62 or another modifier may apply.

Procedure Not Eligible

The procedure is not eligible for team-surgeon reimbursement.

Insufficient Documentation

The operative record does not establish team participation or medical necessity.

Incorrect Team Assumption

Multiple physicians were involved, but the circumstances did not constitute a qualifying surgical team.

How to Prevent Modifier 66 Denials

Verify CPT

Confirm the procedure’s current team-surgery status before billing.

Confirm Team

Verify that the actual circumstances meet the applicable team surgery criteria.

Verify Specialties

Confirm the participating surgeons and their specialties.

Document Necessity

Ensure the operative record supports why the surgical team was required.

Check Payer

Review current Medicare, Medicaid or commercial payer requirements.

Audit Denials

Track Modifier 66 denials by CPT, payer and provider to identify recurring billing problems.

Modifier 66 Decision Workflow

Use this checklist before billing or appealing.

1 Is the procedure eligible for team-surgeon reporting?

2 How many surgeons participated?

3 What specialties were involved?

4 Does the situation meet the applicable definition of a surgical team?

5 Is the team medically necessary?

6 Does the documentation support the team?

7 Is Modifier 66 the correct modifier?

8 Does the payer require pricing by report?

9 Submit the claim with required documentation.

10 Monitor adjudication and work any denial using the payer’s correction or appeal process.

      
        Modifier 66 Quick Cheat Sheet
      
        Modifier 66 = Surgical Team.
      
        For Medicare, team surgery involves more than two surgeons of
        different specialties for a specific procedure.
      
        The procedure must qualify for team-surgeon reporting.
      
        Medical necessity for the team must be supported.
      
        Documentation must be sufficient for payer review.
      
        Medicare team-surgery claims require sufficient information
        to allow pricing by report.
      
        Do not use Modifier 66 simply because multiple physicians were
        involved.
      
        Two surgeons of different specialties generally point to
        Modifier 62 under Medicare’s co-surgery rules.
      
        An assistant surgeon is not automatically a surgical team.
      
        Check the current Medicare team-surgery indicator.
      
        Indicator 0 means team surgeons are not allowed.
      
        Indicator 1 means team surgeons could be paid with supporting
        documentation establishing medical necessity.
      
        Indicator 2 means team surgeons are allowed and payment is by
        report.
      
        Indicator 9 means the team-surgery concept does not apply.
      
        Always verify current payer-specific requirements.

Modifier 66 and Medicare

Medicare Review Checklist

Verify the CPT procedure.
Check the current team-surgery indicator.
Identify all surgeons involved.
Verify the specialties involved.
Establish medical necessity for the team.
Review the operative documentation.
Confirm sufficient information for pricing by report.

CMS Guidance

CMS’s Medicare Claims Processing Manual states that when a team of surgeons involving more than two surgeons of different specialties is required for a specific procedure, each surgeon bills the procedure with Modifier 66.

The same guidance states that claims for team surgeons must contain sufficient information to allow pricing by report.

CMS also identifies team-surgery indicators in its status indicator resources.

Modifier 66 and Medicaid

Medicaid Review

Identify the state Medicaid program.
Check state Medicaid modifier policy.
Verify team-surgery reimbursement rules.
Review the state fee schedule.
Check MCO-specific requirements.
Verify documentation requirements.

Important Medicaid Point

Medicaid reimbursement rules can vary by state and managed-care organization.

CMS Medicaid NCCI resources should be considered alongside the applicable state Medicaid program and MCO policy.

Modifier 66 and Commercial Insurance

Check Contract

Verify whether the payer recognizes team-surgery services under its current reimbursement policy.

Verify CPT

Confirm that the specific procedure supports Modifier 66.

Documentation

Maintain operative and supporting documentation demonstrating the team and medical necessity.

CMS NCCI Reminder

CMS states that NCCI promotes correct coding and reduces improper Medicare Part B payments.

CMS also explains that claim-specific NCCI questions and appeals should be directed to the responsible Medicare Administrative Contractor.

Do not add a modifier merely to bypass a coding edit. The clinical circumstances must actually support the modifier.

Modifier 66 FAQs

What is Modifier 66?

Modifier 66 identifies a qualifying surgical-team service. Under Medicare’s general team-surgery guidance, this involves more than two surgeons of different specialties required to perform a specific procedure.

What does Modifier 66 mean in medical billing?

It tells the payer that the procedure required the services of a surgical team under the applicable coding and reimbursement rules.

How many surgeons are required for Modifier 66?

For Medicare, the Claims Processing Manual describes a surgical team as more than two surgeons of different specialties required for a specific procedure.

Is Modifier 66 the same as Modifier 62?

No. Modifier 62 is associated with co-surgeons, while Modifier 66 is associated with qualifying surgical-team services.

Can two surgeons use Modifier 66?

For Medicare’s general rules, two surgeons of different specialties required for a specific procedure fall under the co-surgery concept and Modifier 62 rather than Modifier 66.

Does having three surgeons automatically mean Modifier 66?

No. The number of physicians alone does not automatically establish a surgical team. The procedure, specialties, actual team participation, medical necessity and payer rules must be evaluated.

Does Modifier 66 guarantee additional payment?

No. Payment depends on the procedure’s eligibility, payer rules, documentation, medical necessity and applicable reimbursement methodology.

What documentation supports Modifier 66?

Documentation should support the procedure, participating surgeons, relevant specialties, medical necessity for the surgical team and other information required by the payer.

What does Medicare require for Modifier 66?

Medicare’s Claims Processing Manual states that when a team of surgeons involving more than two surgeons of different specialties is required for a specific procedure, each surgeon bills with Modifier 66. Claims must contain enough information to establish team medical necessity and allow pricing by report.

What is the Medicare team-surgery indicator?

CMS identifies team-surgery indicators: 0 means team surgeons are not allowed; 1 means they could be paid with supporting documentation establishing medical necessity; 2 means team surgeons are allowed and payment is by report; and 9 means the concept does not apply.

What should an AR caller check first on a Modifier 66 denial?

Start with the EOB or ERA. Identify the denial reason, CPT code, current team-surgery indicator, number and specialties of surgeons, medical-necessity documentation and payer requirements.

Can Modifier 66 be appealed?

If the claim is correctly supported and the payer denied it incorrectly, an appeal or reconsideration may be appropriate. Submit the documentation required by the payer and follow its appeal process.

Is Modifier 66 an NCCI modifier?

Modifier 66 is a surgical-team modifier. CMS’s NCCI materials distinguish the modifiers used to bypass NCCI Procedure-to-Procedure edits from other CPT modifiers. Do not use Modifier 66 simply to bypass an NCCI edit.

Is Modifier 66 used for assistant surgeons?

No. Modifier 66 identifies a surgical-team circumstance. An assistant surgeon is reported using the applicable assistant-surgeon modifier when its requirements are met.

What is the biggest Modifier 66 billing mistake?

One common mistake is treating any situation involving multiple physicians as a surgical team without verifying the procedure, team criteria, medical necessity and payer rules.

      
        Before You Bill Modifier 66
      
        Confirm the exact CPT procedure.
      
        Verify that the procedure is eligible for team-surgeon
        reporting.
      
        Identify all participating surgeons.
      
        Verify their specialties.
      
        Confirm that the circumstances represent a true surgical team.
      
        Establish medical necessity for the team.
      
        Review the operative report.
      
        Check the current Medicare team-surgery indicator.
      
        Ensure sufficient information is available for pricing by
        report.
      
        Do not confuse Modifier 66 with Modifier 62.
      
        Do not confuse Modifier 66 with assistant-surgeon modifiers.
      
        Check payer-specific requirements before submission.

Official CMS References

Use current official sources when validating Medicare coding, team-surgery and NCCI requirements.

CMS — Medicare Claims Processing Manual, Chapter 12 Official Medicare physician/nonphysician practitioner claims processing guidance, including co-surgery and team-surgery rules. CMS — Status Indicators CMS guidance identifying Medicare team-surgery indicators 0, 1, 2 and 9. CMS — Medicare NCCI Policy Manual Current 2026 Medicare NCCI Policy Manual, effective January 1, 2026. CMS — Medicare NCCI Official CMS National Correct Coding Initiative resources, including policy manuals, edits and appeal information. CMS — Medicare NCCI FAQ Library Official CMS FAQs covering NCCI policies and modifier guidance. CMS — Medicaid NCCI Policy Manual Official Medicaid NCCI policy resource.

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