The Most Common Coding Mistakes in Orthopedics

Small coding errors can create big revenue problems.

Orthopedic coding can get complicated quickly.

One patient may have an office visit, X-rays, an injection, a brace, fracture care, and eventually surgery — all for the same condition. Then add laterality, modifiers, global periods, multiple procedures, payer edits, and documentation requirements.

Suddenly, a seemingly straightforward orthopedic encounter isn't so straightforward.

When we review orthopedic coding, we often find that the biggest problems aren't necessarily obscure coding rules. They're recurring mistakes happening in everyday encounters.

And those mistakes can go in both directions. Some result in overbilling and compliance risk. Others result in services never being billed at all.

Here are some of the most common orthopedic coding mistakes practices should be watching for.

1. Missing Billable E/M Services With Procedures

A patient comes in with knee pain. The physician performs an evaluation, reviews imaging, considers treatment options, assesses the patient's condition, and ultimately decides to perform an injection.

The claim contains only the injection. Why? Someone assumed: "You can't bill an office visit when you do a procedure."

That's not always true. When a significant, separately identifiable E/M service is performed on the same day as a minor procedure and the documentation supports it, the E/M may be separately reportable with Modifier 25.

But there is an important warning here. The opposite mistake happens too. An E/M isn't automatically billable just because the physician spoke to the patient before performing a procedure. Every procedure includes some inherent evaluation and pre-service work.

The question is whether the E/M went above and beyond the usual work associated with the procedure.

2. Modifier 25 Becomes an Automatic Modifier

Once practices learn about Modifier 25, another problem sometimes develops. Every injection gets an E/M. Every minor procedure gets an E/M. And every E/M automatically gets Modifier 25.

That's not what Modifier 25 is for. The documentation must support a significant and separately identifiable E/M service.

Using Modifier 25 as an automatic payment mechanism can create unnecessary payer scrutiny and audit risk. The modifier should describe what happened during the encounter. It shouldn't be used simply because your billing software allows it.

3. Forgetting Modifier 57 When the Decision for Surgery Is Made

This is particularly important for orthopedic surgeons.

A patient presents with a displaced fracture. The surgeon evaluates the patient, reviews the imaging, discusses treatment options and risks, and determines that operative management is necessary. The patient undergoes major surgery.

The E/M service that resulted in the decision for surgery may be separately reportable with Modifier 57 when the requirements are met. Yet practices frequently:

Don't bill the E/M at all, or
Incorrectly append Modifier 25.

Remember the basic distinction:

Modifier 25 — significant, separately identifiable E/M associated with a minor procedure.
Modifier 57 — E/M that results in the decision to perform major surgery.

Those aren't interchangeable.

4. Fracture Care Coding Without Understanding What Was Actually Done

Fracture coding is one of the biggest areas of confusion in orthopedics. Not every fracture encounter should automatically generate a fracture treatment code.

The coding decision depends on factors such as:

Type of fracture
Location
Whether treatment was open or closed
Whether manipulation was performed
Whether fixation was used
Whether the physician is providing definitive fracture management

One of the biggest problems occurs when the clinical documentation doesn't clearly describe the treatment. Simply writing "Fracture. Continue brace. Follow up in four weeks" may not give the coder enough information to determine exactly what occurred.

5. Forgetting That Fracture Treatment Has a Global Period

This mistake often follows the previous one.

Once definitive fracture care is reported, subsequent related visits may fall within the global surgical package. If your staff doesn't recognize that, routine follow-up visits can accidentally be billed as separate E/M services.

On the other hand, practices sometimes assume every encounter during that period is included. That's also incorrect. An unrelated problem during the global period may potentially support a separately reportable E/M service with Modifier 24 when requirements are met.

The question isn't simply "Is the patient in a global?" It's "Why are we seeing the patient today?"

6. Missing Casting and Splinting Opportunities

Casting and splinting can become particularly confusing when combined with fracture treatment. Depending on the circumstances, the application of a cast or splint may or may not be separately reportable. Supplies may also have separate HCPCS reporting considerations.

This is an area where practices can easily:

Bill something already included,
Forget a separately reportable supply, or
Miss a service entirely.

The workflow matters. If clinical staff apply the cast but no charge makes it to the coder, the service can disappear before billing ever sees it.

7. Laterality Errors

Orthopedics lives in a world of right, left, and bilateral. Yet laterality mistakes remain incredibly common.

The note says right knee. The diagnosis says left knee. The procedure code gets RT. The claim contains an ICD-10-CM code identifying the opposite side.

Now the payer receives a claim that doesn't tell one consistent story. These mistakes can cause:

Denials
Claim edits
Medical record requests
Delayed reimbursement

And sometimes they create a much larger documentation integrity problem. The diagnosis, procedure, operative report, and modifiers should all agree.

8. Incorrect Bilateral Procedure Reporting

Bilateral procedures aren't always as simple as adding Modifier 50. Different procedures and payers may have different reporting requirements.

Depending on the code and payer, bilateral services may require:

Modifier 50
RT and LT on separate lines
Units
Another payer-specific reporting method

Before developing an automatic workflow, verify how the particular code and payer expect the service to be submitted. One bilateral billing rule does not fit every claim.

9. Injection Coding Mistakes

Orthopedic practices perform a tremendous number of injections, which means even small errors can multiply quickly. Common problems include:

Incorrect joint or bursa injection code
Incorrect anatomic site
Missing laterality
Missing drug code
Incorrect drug units
Incorrect NDC information when required
Billing an unsupported E/M service
Failing to document medication, dose, or site

One injection error isn't necessarily financially significant. Repeat that error hundreds or thousands of times a year? Now you have a revenue integrity problem.

10. Drug Units Don't Match What Was Administered

This deserves special attention. The amount documented clinically doesn't always translate directly into one billing unit. HCPCS drug codes have specific unit definitions.

If staff document the amount administered but the billing team doesn't convert that amount into the correct billable units, the practice can either underbill and lose reimbursement, or overbill and create repayment and compliance exposure.

Your clinical inventory, documentation, charge entry, and billing units should reconcile.

11. Missing Imaging Charges or Billing the Wrong Component

Orthopedic practices rely heavily on imaging. That creates another common coding problem.

Who owns the equipment? Who performs the technical component? Who interprets the study?

Depending on the arrangement, the practice may be entitled to bill:

The global service,
The professional component, or
The technical component.

That's where Modifier 26 and TC become important when applicable. Practices should also ensure the imaging documentation supports the service and interpretation being reported.

12. Not Recognizing Separate Procedures During the Same Operative Session

Orthopedic surgery often involves multiple procedures during the same operative encounter. But just because two CPT codes describe work performed doesn't mean both are separately payable.

You have to consider:

NCCI edits
Bundling rules
Separate anatomic sites
Distinct lesions or injuries
Different compartments
Whether one procedure is integral to another
Whether a modifier is appropriate

This is where Modifier 59 and the X{EPSU} modifiers are often misunderstood. A modifier should never be appended simply to "unbundle" two codes so the payer will pay them. The operative report must support why the services are distinct.

13. Coding From the Procedure Title Instead of the Operative Report

This is a big one. The scheduled procedure says "ORIF ankle." That doesn't mean the coder should automatically select an ORIF code from the schedule.

The operative report may reveal:

Different fracture anatomy
Multiple fractures
No fixation of a particular fracture
Syndesmotic repair
Additional procedures
Procedures planned but not performed
Unexpected intraoperative findings

The surgical schedule tells you what was planned. The operative report tells you what actually happened. Code the latter.

14. Missing Separately Reportable Services Hidden in the Operative Note

This is the opposite problem. Sometimes the primary procedure is coded correctly, but additional work documented in the operative report is never reviewed for separate reportability.

That doesn't mean every sentence in the operative report deserves another CPT code. Many services are integral to the primary operation. But the coder should at least evaluate the entire operative report rather than stopping after finding the first procedure.

Accurate coding requires understanding the whole surgery.

15. Assuming Everything Post-Op Is Included

We see this mistake repeatedly. The patient had surgery, so every subsequent encounter gets marked NO CHARGE — POST-OP.

But what if the patient comes back with an unrelated shoulder problem after knee surgery? What if they sustain a new injury? What if the surgeon evaluates an entirely unrelated condition?

A patient can be within a postoperative period without every service being postoperative care. Modifier 24, 58, 78, or 79 may become relevant depending on what actually occurred.

Don't let the words "global period" automatically shut down the coding process.

16. Documentation Doesn't Support the Complexity Being Billed

Orthopedic notes can become extremely templated. The history is long. The physical examination is detailed. The note may be several pages.

But E/M coding isn't based on how many words appear in the record. Under current office/outpatient E/M rules, code selection generally relies on medical decision making or total time when appropriately used. What matters is the work performed and documented.

Providers should clearly capture:

Problems addressed
Data reviewed and analyzed
Independent interpretation when applicable
Discussions with other clinicians when applicable
Treatment decisions
Prescription drug management
Decisions regarding surgery
Risks associated with patient management

A longer note isn't necessarily a higher-level visit.

17. Under-Coding Because the Provider Is Afraid of an Audit

Not every orthopedic coding mistake results in overpayment. Some of the most expensive mistakes result in underpayment.

Providers may automatically select lower E/M levels because they believe: "I'd rather be safe."

But compliant coding doesn't mean always choosing the lower code. It means selecting the code supported by the documentation. If the physician legitimately performed higher-complexity medical decision making and documented it appropriately, intentionally reporting a lower level creates its own revenue integrity problem.

18. Letting the EHR Make the Coding Decision

EHRs are helpful. Templates are helpful. Automated coding suggestions can be helpful. But none of them replace coding judgment.

An EHR doesn't always understand:

The clinical context
Payer-specific rules
Global surgery relationships
NCCI edits
Whether services are truly distinct
Whether documentation supports a modifier

Technology should support your coding process. It shouldn't become your coding department.

The Bigger Problem: These Errors Repeat

The real financial danger isn't one incorrect orthopedic claim. It's a workflow that creates the same error hundreds of times.

Imagine a practice consistently:

Missing E/M services with injections,
Failing to capture drug units correctly,
Missing Modifier 57,
Writing off unrelated global-period visits, or
Failing to capture supplies.

One claim may represent $50, $100, or $200. Multiply that across several orthopedic surgeons, thousands of encounters, and twelve months.

Suddenly, a "small coding issue" isn't small anymore.

How Practice Owners Can Find the Problems

Don't audit everything at once. Start with high-volume services. Take a sample of:

Joint injections
Fracture care
Casting and splinting
X-rays
E/M + procedure encounters
Surgical cases
Global-period encounters
Drug administration

Then compare three things:

What does the medical record say happened?
What was coded?
What actually appeared on the claim?

Those three things should tell the same story. When they don't, you've found an opportunity.

The Bottom Line

Orthopedic coding isn't just about finding the right CPT code. It's about connecting the patient, the documentation, the procedure, the diagnosis, the modifier, the payer rule, and the claim.

A breakdown anywhere in that chain can result in a denial, underpayment, missed charge, or compliance problem.

The goal shouldn't be to bill more. And it shouldn't be to bill less out of fear. The goal is to bill accurately for the work that was actually performed and properly documented.

Because the most expensive orthopedic coding mistakes aren't always the dramatic ones. They're the small ones your practice repeats every single day.