CurrentHumanaPolicy CP2013100

Assistant at Surgery Reimbursement

Defines Humana Medicare Advantage payment and reimbursement rules for services billed as an assistant at surgery (physician or nonphysician practitioner) and applies to claims for Humana MA enrollees.

Policy Summary

PayerHumana

PolicyAssistant at Surgery Reimbursement

Policy CodePolicy CP2013100

Change TypeNo material change

Effective Date

Next Review Date

Key ActionSubmit assistant-at-surgery charges with the same procedure code as the primary surgeon and the appropriate assistant modifier; only one assistant modifier (AS, 80, 81, or 82) may be billed per charge.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

16%allowed reimbursement rate for assistant at surgery (physician or NPP)

16%amount allowed for contracted physicians acting as assistant

16% MPFSamount allowed for noncontracted physicians

13.6%amount allowed for noncontracted NPPs

Onemodifier limit

Assistant at Surgery — Coverage and Payment Rules

Assistant at surgery coverage and payment rules

Coverage determination and allowed amounts

Assistant at surgery services are payable when provided by a physician or a non-physician practitioner (NPP) consistent with Original Medicare; charges from other individuals are not payable.

Humana uses the MPFS Relative Value File assistant at surgery indicator to determine if an assistant at surgery is medically necessary; Humana internal criteria apply when the MPFS file is not definitive.

In teaching hospitals, coverage for an assistant at surgery is determined consistent with CMS qualifications for an Original Medicare enrollee.

Only one assistant-at-surgery modifier (AS, 80, 81, or 82) may be billed per charge.

Payment rules (when medically necessary)

Policy Summary

PayerHumana

PolicyAssistant at Surgery Reimbursement

Policy CodePolicy CP2013100

Change TypeNo material change

Effective Date

Next Review Date

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.

CPT Codes and Modifier Requirements

Assistant-at-surgery CPT codesCPT

59514	Cesarean delivery only (when assistant billed for cesarean assistance)
59620	Cesarean delivery only, following attempted vaginal delivery after previous cesarean delivery (when assistant billed for cesarean assistance)

Assistant-at-surgery modifiersModifier

AS	Modifier AS: Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
80	Modifier 80: Assistant surgeon
81	Modifier 81: Minimum assistant surgeon
82	Modifier 82: Assistant surgeon (when qualified resident surgeon not available)

Modifier limit

Modifier billing limitOnly one of the modifiers AS, 80, 81 or 82 should be billed per charge.

Procedure coding ruleAssistant should bill the same procedure code as the primary surgeon and the appropriate assistant modifier, except for cesarean delivery where CPT 59514 or 59620 is billed with the assistant modifier.

Cesarean assistance reimbursementHumana will not reimburse more than the assistant-at-surgery rate applicable to the delivery-only CPT code when assistant only during cesarean delivery is billed.

Key Definitions

Assistant at surgery

DefinitionAssistant at surgery services are services rendered by physicians or nonphysician practitioners (NPPs) who actively assist the physician in charge of performing a surgical procedure.

Coverage limitationA charge for an assistant at surgery service provided by an individual whose service would not be coverable for an Original Medicare enrollee is not payable; such charges are denied to provider liability.

Medical necessity determinationHumana uses the MPFS Relative Value File assistant at surgery indicator to determine medical necessity; when the file is not definitive, Humana's internal criteria are used.

Base maximum amount payable under the member's plan

DefinitionThe maximum amount of reimbursement for a covered expense, determined by the member's plan; may be the maximum allowable fee, the appropriate Medicare fee schedule rate, or an amount from another payment model.

Plan payment noteActual plan reimbursement may be less than this base maximum amount because of applicable adjustments.

Relation to MAFDepending on the plan, the base maximum amount payable may be the MAF or a Medicare fee schedule rate.

Maximum allowable fee (MAF)

DefinitionMaximum allowable fee (MAF): The maximum amount of reimbursement for a covered expense, determined by the member's plan provisions.

Actual paymentActual plan payment may be less than MAF because of applicable adjustments.

Role in reimbursementMAF may serve as the base maximum amount payable under a member's plan, depending on plan provisions.

MPFS Relative Value File

DefinitionMedicare Physician Fee Schedule (MPFS) Relative Value File: A CMS file that includes assistant at surgery indicator, relative value units (RVUs) and conversion factors used to determine physician service payments.

Use by HumanaHumana uses the MPFS Relative Value File assistant at surgery indicator to determine if an assistant at surgery is medically necessary; internal criteria apply when the file is not definitive.

ContentThe file includes assistant at surgery indicators, RVUs and conversion factors for physician services (commonly referred to as the RVU table).

OpenPayer

Assistant at Surgery Reimbursement

Assistant at Surgery — Coverage and Payment Rules

CPT Codes and Modifier Requirements

Claims Processing and Provider Responsibilities

Key Definitions