Modifier 24: The Forgotten Modifier

The patient is in a global period. That doesn't automatically mean the visit is free.

There is a phrase we hear all the time in surgical practices:

"We can't bill it. The patient is still in the global."

Sometimes that's absolutely correct. But sometimes it isn't.

And when practices automatically write off every E/M encounter that occurs during a post-operative global period, they may be giving away medically necessary services that were never included in the original surgery.

That brings us to one of the most overlooked modifiers in physician billing: Modifier 24.

It may only be two characters, but understanding when to use it can make a meaningful difference in both revenue and compliance.

What Is Modifier 24?

Modifier 24 identifies an unrelated evaluation and management service by the same physician or other qualified healthcare professional during a postoperative period.

The most important word in that definition is unrelated.

Modifier 24 doesn't make routine post-operative care separately billable. Instead, it tells the payer:

"Yes, this patient is currently in a global surgical period — but today's E/M service is unrelated to that surgery."

That's an important distinction.

The Global Period Does Not Make the Patient "Untouchable"

This is where the confusion begins.

When a physician performs a procedure with a global period, certain related post-operative services are included in the payment for that procedure. Routine follow-up may include services such as:

Evaluating normal healing
Routine incision or wound checks
Removing sutures or staples
Routine dressing changes
Managing expected post-operative discomfort
Discussing normal recovery
Providing standard activity instructions

Those services generally aren't separately payable because the physician has already been reimbursed for them through the global surgical package.

But the global period applies to services related to the surgery. It doesn't mean every medical problem the patient develops for the next 10 or 90 days suddenly becomes part of that operation.

Here's a Simple Example

An orthopedic surgeon performs a total knee replacement.

Three weeks later, the patient returns because of an unrelated shoulder injury after a fall. The physician evaluates the shoulder, reviews imaging, diagnoses the injury, and develops a treatment plan.

The patient happens to be within the global period for the knee replacement. But ask yourself: was treatment of the shoulder included in the payment for the knee surgery?

Of course not.

That's exactly the type of situation where Modifier 24 may be appropriate.

The Biggest Modifier 24 Mistake

Ironically, one of the biggest mistakes we see isn't inappropriate use of Modifier 24. It's not using it at all.

Practices see the global period indicator and automatically assume: "No charge."

The encounter gets marked as post-op. No claim is generated. No coder reviews whether the condition was related or unrelated. And potentially legitimate revenue disappears before it ever reaches the billing system.

That's not a denial. That's a missed charge.

When Modifier 24 May Be Appropriate

Consider another example.

A general surgeon performs a hernia repair. During the global period, the patient presents to the same physician for evaluation of an unrelated breast mass. The surgeon performs a medically necessary E/M service addressing that separate condition.

The fact that the patient recently had hernia surgery doesn't automatically make evaluation of the breast mass part of the hernia repair.

When the documentation clearly establishes the unrelated condition, Modifier 24 may allow the E/M service to be reported separately.

But What About Surgical Complications?

This is where practices need to be careful. A complication does not automatically mean Modifier 24.

Why? Because Modifier 24 specifically describes an unrelated E/M service. If the patient returns because of a problem associated with the surgery, simply adding Modifier 24 to obtain payment is not appropriate.

For example, a patient returns after abdominal surgery with:

Incisional pain
Drainage from the surgical wound
Redness around the incision
Concern about post-operative healing

Those issues may still be related to the original surgical procedure. The coding decision depends on the circumstances, the service performed, the global surgery rules, and applicable payer policy.

Modifier 24 should never be used simply to override a global-period denial.

Modifier 24 Is for E/M Services

Another common mistake is attaching Modifier 24 to a procedure. Modifier 24 applies to an evaluation and management service during the post-operative period.

If the patient requires another procedure during the global period, a different modifier may be necessary depending on why that procedure is being performed. For example:

Modifier 58 may apply to certain staged, related, or more extensive procedures.
Modifier 78 may apply to certain unplanned returns to the operating or procedure room for related procedures during the post-operative period.
Modifier 79 may apply to an unrelated procedure or service performed during the post-operative period.

The modifier should describe what actually happened — not simply what gets the claim through the payer's edits.

Modifier 24 vs. Modifier 25

These two modifiers are also frequently confused.

Modifier 24 — think: unrelated E/M during the post-operative global period.
Modifier 25 — think: significant, separately identifiable E/M on the same day as another procedure or service.

And yes, there are circumstances in which more than one modifier may be relevant to an E/M service.

That's why coding based solely on the calendar — or simply seeing "global period" — isn't enough. You have to understand the encounter.

Documentation Has to Tell the Story

If you're telling an insurance company that today's visit is unrelated to the patient's recent surgery, the medical record needs to make that distinction clear.

The note should establish:

Why the patient is being seen
The condition being evaluated
How that condition differs from the surgical diagnosis
The assessment and medical decision making performed
The treatment plan
Why the service is medically necessary

The payer shouldn't have to guess why the visit is unrelated. And neither should your coder.

Stop Labeling Every Visit "Post-Op"

This is an important workflow issue.

A patient can be post-operative without the encounter itself being post-operative care. Those are two very different things.

If your scheduling or EHR workflow automatically categorizes every encounter during a global period as "post-op," legitimate E/M services can disappear.

Your staff should ask: Why is the patient being seen today?

Not simply: Is the patient currently in a global period?

That small change in thinking can uncover missed billing opportunities.

What Practice Owners Should Review

Pull a sample of encounters that occurred during 10- and 90-day global periods. Then look at the encounters that were never billed, and ask: were all of them truly routine post-operative care?

You may be surprised.

Look specifically for:

New injuries
Unrelated diagnoses
Separate chronic conditions
New symptoms unrelated to surgery
Evaluations involving meaningful medical decision making

Then compare the documentation to what actually reached the claim.

This isn't about finding ways to bill routine post-op visits. It's about making sure legitimate services aren't being automatically discarded simply because the patient happens to be in a global period.

Don't Use Modifier 24 Just to Get a Claim Paid

There is an equally important compliance message here. A modifier isn't a denial bypass button.

Modifier 24 should only be reported when the encounter actually meets the requirements and the documentation supports it.

If your billing company responds to a global-period denial by automatically adding Modifier 24 and resubmitting the claim without reviewing the medical record, that's a problem.

The question shouldn't be: "Which modifier will make this pay?"

The question should be: "What happened during this encounter, and which modifier accurately communicates that to the payer?"

That's compliant coding.

The Bottom Line

Modifier 24 may be one of the most forgotten modifiers in physician billing. Not because it's complicated, but because many practices operate under one enormous assumption:

"If the patient is in the global period, we can't bill an E/M."

That's not the right question. Instead, ask: "Why is the patient being seen today?"

If it's routine care related to the surgery, it's generally part of the global package. If it's a medically necessary, unrelated E/M service, Modifier 24 may be exactly what your claim is missing.

The patient may still be post-op. But that doesn't mean every problem they have belongs to the surgery.