Glossary · Coding

Modifier 62 (co-surgeon)

Modifier 62 is appended by each of two surgeons to the same CPT code when both are required as primary surgeons—each performing a distinct portion of a single procedure during the same operative session. Medicare pays each surgeon 62.5% of the fee schedule allowable (125% split equally) rather than the full 100%.

Verified May 8, 2026 · 8 sources ↓

Drawn from NovitasCMSComplianceNoridianAAPC

Definition

Source · Editorial summary grounded in 8 cited references ↓

Co-surgery exists when a single procedure is so complex—technically or because of patient condition—that two surgeons must each perform distinct, inseparable components simultaneously or in defined sequence under one operative session, all captured by one CPT code. Classic orthopedic examples include bilateral simultaneous joint replacements and complex anterior-posterior spinal reconstruction where one surgeon manages the approach and closure while the other performs the definitive spinal work. Each surgeon independently appends modifier 62 to that shared CPT code and submits a separate claim; neither surgeon bills a different code for their portion.

The Medicare Physician Fee Schedule assigns every CPT code a co-surgery indicator. An indicator of '0' means co-surgery is not payable—period. An indicator of '1' means co-surgery may be paid, but the claim suspends for manual review and the surgeon must submit documentation establishing medical necessity. An indicator of '2' means co-surgery is routinely recognized; if the two-specialty requirement is satisfied, no additional documentation is needed, though it is still best practice to include operative notes.

Reimbursement math is straightforward: Medicare prices the procedure at 125% of the standard allowable and divides that equally, so each surgeon receives 62.5% of the fee schedule amount. If only one surgeon appends modifier 62 and the other does not, the unmodified claim processes first at 100% and the second claim is rejected as a duplicate—costing one surgeon their entire payment. Coordination between co-surgeons on both documentation and claim submission is therefore not optional.

Why it matters

Failing to coordinate modifier 62 billing creates a concrete financial and compliance risk: the surgeon whose claim arrives second—without the modifier aligned—faces outright denial or duplicate-claim rejection, with no straightforward path to recovery after the fact. On the audit side, CMS and commercial payers scrutinize co-surgery claims because they represent a higher payment than a single-surgeon procedure; missing documentation of medical necessity for indicator-1 codes is one of the OIG's recurring targets in orthopedic and spine billing reviews. Incorrectly using modifier 62 on a code with a '0' indicator results in automatic denial, while applying it to procedures that are actually sequential (not simultaneous or interdependent) can trigger fraud-and-abuse inquiries.

Common mistakes

Where people most often go wrong with this concept.

Source · Editorial brief grounded in cited references ↓

Appending modifier 62 to a CPT code that carries a co-surgery indicator of '0'—those codes are categorically ineligible and will be denied regardless of clinical justification.
One surgeon submitting the claim without modifier 62 while the co-surgeon uses it, causing the unmodified claim to process at 100% and the modified claim to be rejected as a duplicate.
Using modifier 62 when two surgeons perform different, separately coded procedures through the same incision—that scenario requires each surgeon to bill their own distinct CPT code without modifier 62, not a shared code with modifier 62.
Confusing co-surgery (modifier 62) with team surgery (modifier 66) or assistant-at-surgery (modifier 80/82); modifier 62 requires both surgeons to function as primary surgeons on the same code, not one assisting the other.
Submitting a co-surgery claim for indicator-1 procedures without attaching an operative note that names the co-surgeon, explains medical necessity, and describes each surgeon's distinct operative work—resulting in automatic suspension and likely denial.
Treating 'tag-team' sequential surgeries—where two surgeons of the same specialty each perform separate, independently codeable procedures back-to-back—as co-surgery; those cases do not meet the definition and should not use modifier 62.
Failing to link the same diagnosis code to the shared procedure on both claims, which can trigger a mismatch denial during payer adjudication.

Related codes

Codes commonly involved when this concept appears in practice.

CPT

ICD-10

M43.16 M51.16 M16.11 M17.11

Modifiers

80 Assistant surgeon AS PA / NP / CNS assistant at surgery 51 Multiple procedures

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 8 cited references ↓

01Do both surgeons have to be from different specialties to use modifier 62?

Medicare's classic definition requires different specialties, but the operative test is whether both surgeons perform distinct, primary components of a single procedure. For indicator-2 codes, the two-specialty requirement triggers automatic payment; for indicator-1 codes, documented medical necessity can support co-surgery even when specialties overlap. Commercial payer rules vary, so verify each payer's policy before billing.

02What happens if only one of the two co-surgeons appends modifier 62?

The claim without the modifier typically processes first at 100% of the fee schedule. When the second claim arrives with modifier 62 on the same code and date of service, the payer treats it as a duplicate and denies it. The surgeon who omitted the modifier may also face a post-payment audit or recoupment if the payer later determines co-surgery rules applied.

03How much does each co-surgeon get paid under Medicare?

Medicare prices the procedure at 125% of its standard allowable and splits that equally, so each surgeon receives 62.5% of the fee schedule amount for that code. For example, if the allowable for a procedure is $1,272, each co-surgeon receives approximately $795.

04Can modifier 62 be used when two surgeons each perform a different, separately codeable procedure on the same patient during the same session?

No. If each surgeon's work corresponds to a distinct CPT code, each surgeon bills their own code without modifier 62. Co-surgery applies only when both surgeons' combined work is captured by a single CPT code.

05What documentation is required for co-surgery claims?

Each surgeon must write their own operative note describing the specific work they personally performed, naming the co-surgeon, explaining why two primary surgeons were medically necessary, and linking the same diagnosis to the shared code. For indicator-1 codes, this documentation must be submitted with the claim via the PWK process; for indicator-2 codes with the two-specialty requirement met, additional documentation is not mandatory but remains best practice.

06Is modifier 62 the same as modifier 66?

No. Modifier 62 covers two-surgeon co-surgery where each surgeon performs a distinct portion of one procedure. Modifier 66 applies to team surgery—typically three or more surgeons required simultaneously for highly complex procedures. Both have separate eligibility indicators on the Medicare Physician Fee Schedule, and the reimbursement rules differ.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

When Mira detects an operative note describing two attending surgeons each performing distinct, primary surgical work under a single procedure, it flags the case for modifier 62 review. The scribe layer checks whether both surgeons' notes are present, whether each note identifies the co-surgeon by name, describes that surgeon's specific operative contribution, and articulates the medical necessity for having two primary surgeons. If the shared CPT code carries a co-surgery indicator of '1', Mira prompts the coder to confirm that compliant documentation is attached via the PWK process before claim release. If the indicator is '2', Mira verifies that the two-specialty requirement is met (different specialty NPIs on both claims) and pre-populates modifier 62 on the shared code for each surgeon's claim. Mira will not auto-apply modifier 62 to any CPT code carrying a '0' indicator and will surface a hard stop if the documented scenario appears to describe sequential rather than simultaneous or interdependent operative work, routing those cases for human review to determine whether modifier 62, modifier 66, or separate primary-surgeon billing is appropriate.

See Mira's approach

Related terms

Modifier 80 (assistant surgeon) Coding

Modifier 80 is appended to a surgical procedure code to identify a physician (MD, DO, or DPM) who provided full assistant-surgeon services during that operation. It signals to payers that a second physician actively participated in the procedure and is billing separately for that assistance.

NCCI (National Correct Coding Initiative) Coding

The National Correct Coding Initiative (NCCI) is a CMS program of automated prepayment edits that prevent Medicare and Medicaid from paying for procedure code combinations that are incorrectly billed together or billed in quantities that exceed what is clinically reasonable.