Medical Billing & Coding Guide

Modifier 24

Complete guide to understanding when Modifier 24 can be reported for an unrelated Evaluation and Management service performed by the same physician or other qualified healthcare professional during a postoperative period.

Start Learning Quick Cheat Sheet

Unrelated E/M During a Postoperative Period

Modifier 24 at a Glance

Understand the core concept before reviewing global surgery rules, examples and denial scenarios.

Modifier

Identifies an unrelated E/M service during a postoperative period.

E/M

Applies To

Evaluation and Management services.

GLOBAL

Timing

The service occurs during an applicable postoperative period.

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Key Test

The E/M service must be unrelated to the original surgical procedure.

DOC

Documentation

Documentation must support the unrelated E/M service.

What Is Modifier 24?

Learn the definition and the central concept behind the modifier.

Simple Definition

Modifier 24 is used to identify an unrelated Evaluation and Management service performed by the same physician or other qualified healthcare professional during a postoperative period.

The E/M service must be unrelated to the surgical procedure that created the postoperative global period.

CMS also requires documentation supporting the unrelated E/M service when Modifier 24 is reported.

Think of Modifier 24 This Way

Patient is in a global period

Patient returns for an E/M service

The medical problem is unrelated to the surgery

↓

Modifier 24 may be appropriate

Understanding the Global Surgical Period

Modifier 24 is closely connected to Medicare’s global surgery rules.

Global Indicator	General Meaning	Postoperative Period
000	Minor procedure with related postoperative work included on the procedure date.	Procedure-date global concept.
010	Minor procedure with applicable postoperative work included.	10-day postoperative period.
090	Major surgery with applicable postoperative work included in the global payment.	90-day postoperative period.
XXX	Global concept does not apply.	Not subject to the standard global surgery concept.

Important: Global surgery indicators vary by service. Always verify the applicable Medicare Physician Fee Schedule and current CMS guidance instead of assuming the global period.

When Should Modifier 24 Be Used?

The key word is unrelated.

The patient is within an applicable postoperative global period.
An E/M service was performed by the same physician or other qualified healthcare professional.
The E/M service is unrelated to the original surgical procedure.
The service is separately reportable under the applicable coding and payer rules.
The medical record supports the unrelated reason for the E/M visit.
The applicable payer requirements have been reviewed.

When Should Modifier 24 NOT Be Used?

Modifier 24 should not be used simply because an E/M service occurred during a postoperative period.

Do not use Modifier 24 for routine postoperative care related to the original surgery.
Do not use it for postoperative recovery services included in the global package.
Do not automatically use it for complications related to the original surgery.
Do not append Modifier 24 when the documentation does not establish that the E/M service is unrelated.
Do not use Modifier 24 for an unrelated procedure. Review the applicable procedure modifier rules, including Modifier 79 when appropriate.

Modifier 24 Decision Guide

Use this simple workflow when reviewing a postoperative E/M claim.

1 Is the patient within an applicable postoperative global period?

2 Was an E/M service performed by the same physician or qualified healthcare professional?

3 Is the E/M service unrelated to the original surgical procedure?

4 Does the documentation clearly support the unrelated reason for the visit?

5 Does the payer allow separate reporting under the applicable circumstances?

✓ If applicable requirements are satisfied, Modifier 24 may be reported on the appropriate E/M code.

Modifier 24 Billing Examples

Practical examples for medical billers, coders and AR callers.

Example 1 — Unrelated Medical Problem

Scenario

A physician performs surgery on a patient. During the postoperative global period, the patient returns for evaluation of an unrelated medical condition.

Potential Reporting

E/M-24

Modifier 24 may be appropriate when the documentation supports that the E/M service is unrelated to the original surgery.

Example 2 — Routine Postoperative Visit

Scenario

The patient returns for routine follow-up related to recovery from the original surgery.

Result

Routine postoperative care is generally included in the global surgical package when applicable.

Modifier 24 would not be appropriate simply because the visit occurred during the global period.

Example 3 — Surgical Complication

Scenario

The patient returns during the global period because of a complication associated with the original surgery.

Important

A complication related to the original surgery is not automatically an unrelated E/M service. Review the applicable global surgery rules.

Example 4 — New Medical Complaint

Scenario

During a postoperative period following surgery, the patient presents for evaluation of an unrelated respiratory complaint.

The provider evaluates and manages the unrelated condition.

Potential Reporting

E/M-24

Example 5 — Same Surgical Condition

Scenario

The patient returns during the global period for continued management of the condition associated with the original surgery.

Result

This is generally related postoperative care, not an unrelated E/M service.

Example 6 — Unrelated Procedure

Scenario

A patient receives an unrelated procedure during a postoperative global period.

Important

Modifier 24 is associated with unrelated E/M services. Review the applicable procedure modifier rules, including Modifier 79 when appropriate.

Modifier 24 vs Modifier 25

One of the most important distinctions for billers and AR callers.

Modifier 24	Modifier 25
Unrelated E/M service during a postoperative period.	Significant, separately identifiable E/M service performed on the same date as another procedure/service when applicable requirements are met.
Global surgery/postoperative period is central to the rule.	Same-day E/M and another procedure/service are central to the rule.
Key concept: unrelated.	Key concept: separately identifiable.
Appended to the appropriate E/M code.	Appended to the appropriate E/M code.

Modifier 24 vs Modifier 79

Both can involve services during a postoperative period, but they apply to different service types.

Modifier 24	Modifier 79
Unrelated E/M service.	Unrelated procedure or service.
Appended to the appropriate E/M code.	Appended to the unrelated procedure/service.
Used during an applicable postoperative period.	Used for an unrelated procedure during an applicable postoperative period.
Does not itself create a new postoperative period.	An unrelated procedure reported with Modifier 79 can begin a new postoperative period when applicable.

Medicare Modifier 24 Rules

Key concepts to understand before correcting or appealing a claim.

What does CMS say about Modifier 24?

CMS describes Modifier 24 as an unrelated Evaluation and Management service by the same physician or other qualified healthcare professional during a postoperative period.

Does the service need to be unrelated?

Yes. The central concept is that the E/M service must be unrelated to the surgical procedure that created the postoperative period.

What about complications?

Do not automatically treat a complication as an unrelated E/M service. Review the applicable global surgery rules and payer guidance.

Does documentation matter?

Yes. Documentation must support the E/M service and establish the circumstances supporting separate reporting.

Can Modifier 24 be used with every postoperative E/M?

No. Routine postoperative care and services related to the original surgery are generally included in the global surgical package when applicable.

Modifier 24 Documentation Requirements

The record should make the unrelated nature of the E/M service clear to a reviewer.

E/M Documentation

Reason for the current visit
Relevant history
Examination when applicable
Medical decision-making
Assessment
Treatment or management plan

Unrelated-Service Support

Clearly identify the current problem
Establish that the problem is unrelated to the original surgery
Support medical necessity
Document the services performed
Support the reported E/M level
Submit supporting records when required

Documentation Test: Could an independent reviewer read the medical record and clearly understand why this E/M service was unrelated to the original surgical procedure?

How Modifier 24 Appears on a Claim

Modifier 24 is appended to the appropriate E/M code.

Claim Field	Example	Explanation
CPT/HCPCS	Appropriate E/M code	Report the appropriate E/M service.
Modifier	24	Identifies the unrelated E/M service during the postoperative period.
Diagnosis	Current condition	Diagnosis should accurately represent the condition evaluated and managed.
Documentation	Medical record	Supports medical necessity and the circumstances of the service.

Common Modifier 24 Denials

Common root causes encountered by AR callers and denial management teams.

Denial 01

E/M Included in Global

The payer considers the E/M service part of the postoperative global package.

Denial 02

Not Unrelated

The documentation does not establish that the E/M service was unrelated to the original surgery.

Denial 03

Documentation Missing

Supporting medical records were not submitted or do not adequately support the service.

Denial 04

Global Period Issue

The payer processed the E/M based on the global period associated with the original service.

Denial 05

Wrong Modifier

The service may require a different modifier based on the type and circumstances of the service.

Denial 06

Surgical Complication

The payer considers the service related to a complication of the original surgery.

How to Work a Modifier 24 Denial

Practical workflow for AR callers and denial management teams.

Review the Original Surgery

Identify the original procedure, date of service and applicable global surgery period.

Verify the Global Period

Confirm whether the original procedure has an applicable postoperative global period.

Review the E/M

Confirm the E/M code, modifier, diagnosis, POS and date of service.

Determine Related vs Unrelated

Compare the current reason for the E/M service with the original surgical condition.

Review Documentation

Confirm that the medical record supports the unrelated E/M service.

Check Payer Policy

Review the payer’s current requirements for postoperative claims and supporting records.

Correct or Appeal

Submit a corrected claim when appropriate or prepare a reconsideration/appeal with supporting documentation.

Follow Up

Record the payer reference number, submission date, expected turnaround and next follow-up.

AR Caller Script for Modifier 24 Denial

“I’m calling regarding a claim that was denied because the E/M service was considered part of the postoperative global period.”

“The E/M service was performed for a condition that was unrelated to the original surgical procedure, and the provider documentation supports the reason for the separate evaluation and management service.”

“Could you please confirm the exact denial reason, the applicable global period, and whether the claim can be reconsidered with the supporting medical records?”

Questions to Ask the Payer

What is the exact denial reason?
What global period was applied?
What was the original surgical procedure?
Is Modifier 24 accepted for this E/M service?
Does the payer require medical records?
What documentation is required for reconsideration?
What is the applicable filing limit?
What is the appeal or reconsideration process?

Modifier 24 Appeal Strategy

Build the appeal around the distinction between postoperative care and an unrelated E/M service.

Identify Original Surgery

State the original procedure and applicable postoperative period.

Identify Current Problem

Clearly explain the condition evaluated during the denied E/M visit.

Explain Why Unrelated

Explain why the current condition is unrelated to the original surgical procedure.

Provide Documentation

Include the medical record and any additional documentation required by the payer.

Reference Applicable Policy

Cite the applicable CMS, MAC or payer policy supporting separate reporting.

Request Reprocessing

Clearly request reconsideration and reprocessing when the claim meets applicable requirements.

Common Modifier 24 Billing Mistakes

01. Automatic Use

Assuming every postoperative E/M service qualifies for Modifier 24.

02. Ignoring Original Surgery

Failing to review the procedure that created the global period.

03. Confusing Related and Unrelated

Treating a postoperative service related to the original surgery as unrelated.

04. Ignoring Documentation

Assuming the modifier itself proves that the service was unrelated.

05. Confusing 24 and 79

Using Modifier 24 for an unrelated procedure instead of the applicable procedure modifier.

06. Ignoring Payer Rules

Assuming every payer uses identical postoperative claim and documentation requirements.

Modifier 24 Practice Scenarios

Test your understanding.

Scenario 1 — Unrelated condition

A patient is within the postoperative period following surgery. The same physician evaluates the patient for a completely unrelated medical condition.

Answer:

Modifier 24 may be appropriate when the E/M service is separately reportable and the documentation supports that it is unrelated to the original surgery.

Scenario 2 — Routine postoperative care

The patient returns for routine follow-up related to healing from the original surgery.

Answer:

This is generally postoperative care included in the global package when applicable. Modifier 24 would not be appropriate merely because the visit occurred during the global period.

Scenario 3 — Unrelated procedure

A patient receives an unrelated procedure during a postoperative global period.

Answer:

Modifier 24 is an E/M modifier. Review the applicable procedure modifier rules, including Modifier 79 when appropriate.

Modifier 24 Interview Questions

What is Modifier 24?

Modifier 24 identifies an unrelated E/M service provided by the same physician or qualified healthcare professional during a postoperative period.

What is the key word for Modifier 24?

The key concept is unrelated.

Can Modifier 24 be used for routine postoperative care?

No. Routine postoperative care is generally included in the global surgical package when applicable.

What is the difference between Modifier 24 and 79?

Modifier 24 is for an unrelated E/M service. Modifier 79 is for an unrelated procedure or service during a postoperative period.

What is the difference between Modifier 24 and 25?

Modifier 24 addresses an unrelated E/M service during a postoperative period. Modifier 25 addresses a significant, separately identifiable E/M service performed on the same date as another procedure or service when applicable requirements are met.

Modifier 24 Quick Cheat Sheet

Patient is within an applicable postoperative global period.
An E/M service was performed.
The E/M service was provided by the same physician or qualified healthcare professional.
The E/M service is unrelated to the original surgical procedure.
Medical necessity is supported.
Documentation supports the unrelated service.
Current payer requirements have been reviewed.

Key Takeaways

Postoperative Period

Modifier 24 applies when the E/M service occurs during an applicable postoperative period.

Unrelated Service

The E/M service must be unrelated to the original surgical procedure.

Documentation

The medical record must support the E/M service and the circumstances supporting separate reporting.

Modifier 24 FAQs

What is Modifier 24 in medical billing?

Modifier 24 is used to identify an unrelated E/M service performed by the same physician or qualified healthcare professional during a postoperative period.

When should Modifier 24 be used?

It may be used when an appropriate E/M service is performed during a postoperative period and the service is unrelated to the original surgery, with supporting documentation and applicable payer requirements satisfied.

Does Modifier 24 apply to procedures?

Modifier 24 is specifically associated with unrelated E/M services. For an unrelated procedure during a postoperative period, review the applicable procedure modifier rules, including Modifier 79 when appropriate.

Can Modifier 24 be used for a surgical complication?

Do not automatically use Modifier 24 for a complication. Services related to complications of surgery are treated under the applicable global surgery rules and may not qualify as unrelated E/M services.

Does Modifier 24 restart the global period?

Modifier 24 identifies an unrelated E/M service. It does not itself create a new postoperative period.

What documentation is needed for Modifier 24?

The record should document the E/M service, medical necessity and the circumstances supporting that the service is unrelated to the original surgical procedure.

Why was my Modifier 24 claim denied?

Common reasons include global-period processing, failure to establish that the service was unrelated, insufficient documentation, payer requirements, or use of an inappropriate modifier.

Does Modifier 24 guarantee payment?

No. Correct modifier reporting does not guarantee payment. The claim must satisfy coding, medical necessity, documentation, global surgery and payer-specific requirements.

Official Resources

Verify current Medicare and payer requirements before billing, correcting or appealing a claim.

CMS — Global Surgery Booklet CMS guidance on global surgery, postoperative periods, Modifier 24 and Modifier 79. CMS — 2026 NCCI Policy Manual Medicare NCCI guidance related to global surgery and postoperative E/M services. CMS — Medicare NCCI FAQ Library CMS information on NCCI and modifier reporting. CMS — Status Indicators Medicare global surgery indicators and related billing information. CMS — Physician Fee Schedule Verify Medicare service and global surgery information.

Master Modifier 24

Learn how to identify, document, bill, audit and resolve Modifier 24 issues with practical medical billing examples and AR denial workflows.

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