CurrentHumanaPolicy CP2015100

Modifiers X{EPSU} (XE, XP, XS, XU)

Defines Humana's billing expectations for reporting HCPCS/CPT modifiers XE, XP, XS, and XU (collectively X{EPSU}) and guidance on when these should be used instead of modifier 59 for Medicare Advantage and Commercial products.

Policy Summary

PayerHumana

PolicyModifiers X{EPSU} (XE, XP, XS, XU)

Policy CodePolicy CP2015100

Change TypeNo material change

Effective DateJan 1, 2015

Next Review Date

Key ActionReport X{EPSU} modifiers (XE/XP/XS/XU) instead of modifier 59 when they more accurately describe a distinct procedural service; do not append X{EPSU} to E/M services.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

4distinct X modifiers

01/2015effective

06/2021revision

Coverage and Billing Rules

Coverage and billing rules for X{EPSU}

Reporting expectations and limitations

Use the most descriptive modifier available: when XE, XP, XS, or XU (collectively X{EPSU}) more accurately describe the circumstances of a distinct procedural service, report that modifier instead of modifier 59.

Do not append modifiers X{EPSU} to evaluation and management (E/M) services.

Claims payments remain subject to medical necessity, reasonableness, and applicable referral/authorization requirements.

Humana payment is still contingent on plan requirements; reporting a modifier does not guarantee payment.

Policy aligns with CMS guidance (effective 01/01/2015) and CPT instructions that modifier 59 should not be used when a more descriptive modifier (XE/XP/XS/XU) is available.

Modifiers: X{EPSU} vs Modifier 59

Policy Summary

PayerHumana

PolicyModifiers X{EPSU} (XE, XP, XS, XU)

Policy CodePolicy CP2015100

Change TypeNo material change

Effective DateJan 1, 2015

Next Review Date

Key ActionReport X{EPSU} modifiers (XE/XP/XS/XU) instead of modifier 59 when they more accurately describe a distinct procedural service; do not append X{EPSU} to E/M services.

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.

Preferred Reporting Guidance and Actions for Providers

Billing Rule

Preferred reporting guidance — When X{EPSU} is more accurate than modifier 59

When one of the CMS X{EPSU} modifiers more accurately describes the circumstances of a distinct procedural service than modifier 59, report the appropriate X{EPSU} modifier instead of modifier 59. Do not append X{EPSU} modifiers to evaluation and management (E/M) services. Claims remain subject to plan requirements including medical necessity, reasonableness, and any applicable referral or authorization rules.

Preferred: report the appropriate X{EPSU} modifier (per CMS guidance) when it more accurately describes the service circumstances than modifier 59
Do NOT append X{EPSU} modifiers to evaluation and management (E/M) services
Claims are subject to medical necessity, reasonableness, and any referral/authorization requirements

Modifier Definitions

Modifier 59 — Distinct procedural service.

TermModifier 59

DefinitionDistinct procedural service.

ContextUsed to report distinct procedural services more generally when a more specific X{EPSU} modifier is not available.

Modifier XE — Separate encounter.

TermXE

DefinitionSeparate encounter.

NotesOne of the X{EPSU} modifiers created by CMS effective 01/2015 to indicate a distinct procedural service subset.

Modifier XP — Separate practitioner.

TermXP

DefinitionSeparate practitioner.

NotesUse when the same procedure is performed by a different practitioner in circumstances that make the service distinct.

Modifier XS — Separate structure.

TermXS

DefinitionSeparate structure.

NotesIndicates the service was performed on a separate anatomical structure, distinguishing it from modifier 59's broader use.

Modifier XU — Unusual non-overlapping service.

TermXU

DefinitionUnusual non-overlapping service.

NotesUse for services that do not overlap usual components of the primary procedure; one of the X{EPSU} modifiers introduced by CMS effective 01/2015.

X{EPSU} — Modifiers XE, XP, XS and XU collectively.

Collective termX{EPSU}

DefinitionModifiers XE, XP, XS and XU collectively.

GuidanceWhen one of the X{EPSU} modifiers more accurately describes a distinct procedural service, report that modifier instead of modifier 59.

XE	Separate encounter
XP	Separate practitioner
XS	Separate structure
XU	Unusual non-overlapping service
59	Distinct procedural service (less specific; use X{EPSU} when appropriate)