CurrentmhnPolicy CC.PP.020

Distinct Procedural Modifiers: XE, XS, XP, & XU

Defines correct billing, documentation, and prepayment review procedures for AMA 'X' subset modifiers (XE, XS, XP, XU) used in place of modifier -59 on hospital and professional claims for members covered by the Health Plan.

Policy Summary

Payermhn

PolicyDistinct Procedural Modifiers: XE, XS, XP, & XU

Policy CodePolicy CC.PP.020

Change TypeAdministrative review — no material coverage changes

Effective DateFeb 28, 2024

Next Review DateFeb 28, 2025

Key ActionProvide documentation on the claim and claim history to support use of XE, XS, XP, or XU for prepayment clinical validation.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

4distinct subset modifiers defined (XE, XS, XP, XU)

prepaymentclaims flagged for validation

hospital & professionalapplies to

referencedCMS guidance

Billing and Documentation Coverage Criteria

Modifier billing and documentation criteria

Billing and review rules for claims using XE/XS/XP/XU modifiers

All claims billed with modifiers XE, XS, XP, or XU are subject to prepayment clinical validation; after validation claims are reimbursed or denied based on correct modifier use.

Documentation supporting the specific modifier must be present in the claim and claim history; each X modifier is reviewed for correct coding in the same manner as modifier -59.

ALL of the following

Examples of documentation support
- XE — evidence that the service occurred during a separate encounter (review checks whether the clinical situation is likely to require more than one encounter per day).

Policy Summary

Payermhn

PolicyDistinct Procedural Modifiers: XE, XS, XP, & XU

Policy CodePolicy CC.PP.020

Change TypeAdministrative review — no material coverage changes

Effective DateFeb 28, 2024

Next Review DateFeb 28, 2025

Key ActionProvide documentation on the claim and claim history to support use of XE, XS, XP, or XU for prepayment clinical validation.

SourceLink

On This Page

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Modifier Coding and -59 Guidance

Distinct Procedural Modifiers (subset of -59)Modifier

XE	Separate Encounter — Service that is distinct because it occurred during a separate encounter
XS	Separate Structure — Service that is distinct because it was performed on a separate organ/structure
XP	Separate Practitioner — Service that is distinct because it was performed by a different practitioner
XU	Unusual Non-Overlapping Service — Service that is distinct because it does not overlap usual components of the main service

Modifier -59 usage

RuleDo not routinely report modifier -59 when a more specific X modifier (XE, XS, XP, XU) applies

Conflict prohibitionDo not bill modifier -59 together with any X subset modifier on the same claim

Regulatory referenceCMS directs use of X modifiers instead of routine -59 due to widespread inappropriate use

Prepayment Review and Documentation Requirements

Prior Authorization

Prepayment clinical validation and documentation requirement

Claims billed with modifiers XE, XS, XP, and XU are flagged by auditing software for prepayment clinical validation. Documentation supporting the specific modifier must be present in the claim and claim history; after clinical validation the claim will be reimbursed or denied based on correct modifier use. Examples of documentation reviewed include evidence of multiple encounters for XE and documentation that two different practitioners of different specialties were involved for XP.

Prepayment clinical validation occurs prior to claims payment; claims will be reimbursed or denied based on the validation outcome.
Documentation supporting the clinical scenario appropriate to the modifier must be included in the claim and claim history (e.g., multiple encounters for XE; different practitioner specialties for XP).
Modifiers are reviewed in the same manner as modifier -59 and require supporting clinical documentation specific to each modifier's scenario.

Definitions of X Modifiers

XE — Separate Encounter

DefinitionXE (Separate Encounter) — Service that is distinct because it occurred during a separate encounter

ApplicationUse when the same or similar procedure is provided in a separate encounter and documentation supports distinct encounter timing

Review triggerClaims billed with XE are flagged for prepayment clinical validation

XS — Separate Structure

DefinitionXS (Separate Structure) — Service that is distinct because it was performed on a separate organ or structure

ApplicationUse when procedures involve different anatomical organs/structures and documentation demonstrates separation

Review triggerClaims billed with XS are flagged for prepayment clinical validation

XP — Separate Practitioner

DefinitionXP (Separate Practitioner) — Service that is distinct because it was performed by a different practitioner

ApplicationUse when a different practitioner (different NPI/clinician) performs the secondary service and documentation identifies the practitioners

Review triggerClaims billed with XP are flagged for prepayment clinical validation

XU — Unusual Non-Overlapping Service

DefinitionXU (Unusual Non-Overlapping Service) — Service that is distinct because it does not overlap the usual components of the main service

ApplicationUse when the secondary service is an unusual non-overlapping service as documented in the medical record

Review triggerClaims billed with XU are flagged for prepayment clinical validation