Today’s coding landscape is more complex than ever, given evolving Centers for Medicare & Medicaid Services (CMS) policies, increased payer scrutiny, artificial-intelligence-driven audit systems, and new diagnostic technologies. It’s no wonder optometrists, among other health care providers, make mistakes that get them in legal trouble.
In an effort to prevent a legal situation from befalling you, here are common billing and coding blunders my colleagues and I see.
Failure to Follow the Revised Evaluation and Management (E/M) Guidelines
Arguably, the biggest coding shift in more than 25 years occurred when the American Medical Association (AMA) revised office/outpatient E/M guidelines. Regardless of this shift, I find that many ODs still code according to the 1997 documentation rules. Associated mistakes made:
• Over-documenting irrelevant history or exam elements. This includes an exhaustive past medical history (PMH) (eg, detailed childhood illnesses, past surgeries unrelated to the eye, or family history of cancer during a simple refraction-related visit) that has no bearing on the presenting problem. This does not raise your code level under 2021 E/M rules. It wastes time, clutters notes, and may appear like “note stuffing,” which auditors flag.
• Underestimating the role of medical decision making (MDM). MDM is now the primary driver of code selection. Yet many ODs still default to lower levels (99212/99213) out of habit, even when their MDM clearly supports moderate complexity. Adding a 1-sentence explanation that MDM—not exam documentation—determines code level helps here.
• Using time incorrectly. This includes counting staff time, testing time, or pre-chart review time.
• Believing a “comprehensive exam” must be coded as 99204 /99214. Many ODs were trained that a “comprehensive” exam automatically equates to a high-level E/M code. This is a 1997 mindset. A “complete” exam does not equal a 99204/99214 unless the MDM or time supports that level.
Upcoding Complexity Sans Meeting AMA Rules
Some ODs choose a higher-level code because the visit “felt complicated,” even though the documented MDM does not meet the criteria. Auditors specifically look for:
1. No documented change in treatment plan.
2. No new tests ordered or interpreted.
3. No clear reason the MDM is moderate rather than low.
4. No documented risk of morbidity or progression.
For example, calling a dry eye disease follow-up “moderate complexity” simply because the patient is symptomatic should be coded 99213, not 99214.
Pro tip: Remember that only total physician time or MDM determines code level—not how many boxes you checked in your electronic medical record.
Billing the Wrong Insurance
I often see either medical plans billed for vision issues or vision plans billed for medical complaints. An example of this is billing the refraction to vision insurance and the visit to medical insurance. Not all payers allow this.
Pro tip: Have front-desk staff clearly document the patient’s chief complaint, plan based on chief complaint, and the patient’s expected financial responsibility before the exam begins.
Any additional information the patient provides to you during the exam should be addressed and incorporated into their medical record, especially if it contradicts the information and financial responsibility discussed during intake. This is because the true chief complaint determines whether the visit is billed to medical or vision insurance.
For example, if a patient presents for a “routine vision exam” but reports to you intermittent flashes during their comprehensive exam, that becomes a medical encounter regardless of what was discussed at check-in.
Same-Day Dual Billing
Dual billing is allowable only when 2 distinct services are performed. Coding 92014 and 92015, and coding 92133 are examples of allowable dual billing.
Misusing Modifiers
Modifiers remain 1 of the most misunderstood areas of coding, particularly with -25, -59 and -24. This is because their correct use requires the provider to know when a service is separately identifiable, distinct, or unrelated to a global period. These decisions depend entirely on documentation and payer-specific bundling policies, which is why errors are so common.
The typical errors I see are:
• Using -25 on every medical visit that includes a minor procedure.
• Forgetting -59 when a procedure is truly distinct.
• Failure to use -24 for postoperative visits unrelated to global care.
Of note: Improper modifier use has been repeatedly identified as an audit trigger in payer program reports, including the Health and Human Services Office of Inspector General Work Plan, various Medicare Administrative Contractor error-rate summaries, and commercial payer 2024–2025 fraud, waste, and abuse reviews. All list modifier misuse (especially -25 and -59) among the top drivers of improper payments.
Billing Diagnostic Testing Incorrectly
I have seen that OD billing and coding compliance has often not kept up with related changes made based on advancements in diagnostic technology.
Examples of mistakes I see here:
• No medical necessity documented.
• Missing interpretation and report (I/R).
• Using the wrong CPT code (especially with corneal imaging, electroretinography [ERG], and meibography).
• Billing “screening tests” to insurance. Screening tests, such as using ocular coherence tomography (OCT) for wellness baseline photos without symptoms, or elective dry eye disease imaging, should not be billed to any insurance. Screening implies there is no complaint, diagnosis, or medical necessity, so these tests must be billed as self-pay only.
• Billing bilateral when monocular is required (or vice versa). The code 92134 is billed per eye, so coding only 1 unit when both eyes are imaged is incorrect. Conversely, 92081 is typically per test, not per eye—so billing RT/LT separately would be inappropriate.
Pro tip: Check with individual payer policies to support medical necessity for testing correctly. Most commercial carriers will follow CMS guidelines but some may choose to build upon these guidelines instead. When you are unsure of whether a test is covered, provide the patient with an Advanced Beneficiary Notice or Notice of Noncoverage. Remember: if it’s not in the chart, it didn’t happen—and insurers increasingly demand clear medical rationale for every performed test.
Failure to Bundle
National Correct Coding Initiative edits remain a major source of confusion. This is because NCCI edits change frequently, vary by payer, and are not intuitive, so many ODs assume 2 tests can be billed together simply because both were performed, not realizing CMS considers 1 component duplicative or inclusive of another.
To help ease this confusion, the following should be bundled:
• 92250 with 92133/92134.
• 92083 with certain neurology codes.
• 92137 with 920X4 and 920X2.
Of note: When you fail to bundle, you risk recoupment.
Crossing Delegation Boundaries
With the rise of advanced technicians and automated refracting systems, crossing delegation boundaries can unintentionally occur. Some examples I see:
• Technicians performing refractions without OD review.
• Nonlicensed staff performing tests requiring OD supervision (eg, some ERG and OCT protocols, depending on the state).
Each state has unique scope-of-practice rules, so violations to these rules can carry consequences for both billing and your license to practice optometry.
Failure to Provide Required Cataract Comanagement Information
The typical errors I see are:
• Missing transfer-of-care dates.
• Incorrect use of -55 and -79 modifiers.
• Mismatch between the surgeon’s claim and the optometrist’s claim.
• Using the wrong date of service (must be date of surgery).
Pro tip: Make sure to receive a transfer-of-care letter from the operating surgeon that documents the exact date the surgeon released the patient’s care to you. This is essential in determining correct modifier use (-54 for surgeon, -55 for OD), ensuring postoperative days add up to 90, and preventing claim denials or accusations of duplicate billing.
Relying on Inaccurate and Incomplete Data
With the rise of modern practice management and electronic health record systems, I have found that ODs often rely on automated reports that are:
• Incomplete.
• Mislabeled.
• Not tied to actual payer reimbursements.
• Not reconciled with Explanation of Benefits/Electronic Remittance Advice data.
This leads to false assumptions about performance, claim denials, or reimbursement patterns.
Pro tips: Routinely audit reimbursement accuracy, claim acceptance rates, denial trends, CPT utilization, and technician vs doctor coding accuracy.
Putting Protections in Place
By having an awareness of common coding mistakes, and staying informed on the latest changes regarding coding and billing, you can achieve proper documentation and accurate coding. I recommend the following resources to accomplish this: the American Optometric Association Coding & Billing Updates, CMS Medicare Learning Network articles, Local Medicare Administrative Contractor websites, Payer-specific policy portals (eg, UnitedHealthcare, Blue Cross, Aetna, etc), Optometric-specific coding newsletters or continuing education programs, and American Medical Association CPT and Editorial Panel updates. OM
