In an ideal world, you see a patient, understand the complexity of the visit, write a note that reflects it, and the correct code follows naturally. In practice, most providers apply a default code for their most common visit type and rarely revisit whether it is accurate. That default is almost always too low.
This chapter covers the most common errors in level-of-service selection and the habits that both protect your revenue and keep you compliant. None of this requires more clinical effort than you are already giving, the work is real; the goal is getting it counted.
The Most Common Error: Reflexive Undercoding
The most widespread coding mistake in outpatient medicine is not overcoding. It is defaulting to a level-3 visit (99213) for patients who clearly meet level-4 (99214) criteria. This happens for several reasons:
First, 99213 feels conservative and safe. Physicians worry that auditors are looking for high codes, and so they use lower codes as a defensive strategy. What they do not realize is that a coding distribution that does not match their clinical reality is itself a compliance risk, it just runs in the opposite direction.
Second, many providers are still operating under the old documentation rules (covered in Chapter 3 ). They do not realize that under the current MDM framework, a significant portion of their established-patient visits genuinely support 99214, two or more chronic conditions actively managed, prescription drugs being adjusted, data being reviewed. There is a second, quieter cost to those bloated notes: the more boilerplate you carry forward, the more room for documentation errors. A copied-forward fourteen-point review of systems or a full exam you did not actually perform is not just wasted text; if it does not match the visit, it can undermine the note's credibility under audit and, in the worst case, look like documentation of work that did not happen.
Third, documentation habits often do not capture the full story of the visit. A note can reflect exactly what happened clinically while failing to document the elements that support a higher code. The clinical work is there; the coding evidence is not written down.
What Auditors Actually Look For
Understanding audit risk helps you understand what compliance actually requires. Auditors, whether from your employer's compliance department, a commercial payer, or a CMS Recovery Audit Contractor (RAC), are looking for statistical anomalies and documentation-to-code mismatches.
Statistical anomalies: If your billing profile shows a dramatically higher percentage of level-5 visits than your peer group, that is a flag. This does not mean level-5 visits are wrong, it means you need to be able to demonstrate, note by note, that each one was justified. Unusually high rates of modifier 25 use, or unusually high procedure-to-E/M ratios, are also commonly flagged.
Documentation mismatches: An auditor pulls a random sample of your highest-coded visits and reads the notes. If a 99215 note does not document high-complexity MDM or sufficient time, the code is unsupported and the claim is at risk. The question an auditor asks is simple: does this note tell a clinical story that justifies this code?
A Simple Framework for Level Selection
A concrete self-check you can run this week: take five of your own recent established-patient notes that you coded 99213. For each, ask whether you addressed two or more problems, or one that was not fully controlled; whether you reviewed any labs, images, or outside records; and whether you managed a prescription. If two of those three are true, the visit was very likely a 99214 that you undercoded. This is more useful than a generic "review your notes" because it points at the single most common gap: level 4 work documented and billed as level 3.
At the end of each patient encounter, ask yourself two questions:
MDM route: How many problems did I address today, and what was the highest-risk thing I decided? Then check columns 1 and 3 of the MDM table. If two of three columns support a given level, that is your code.
Time route: How much total time did I spend on this patient today, including pre-visit review and post-visit work? Check the time thresholds. If time supports a higher level than MDM, use time, and document the total time in your note.
You pick whichever method supports the higher code, as long as the documentation reflects it honestly.
The "New Patient" vs. "Established Patient" Distinction
New patient codes (99202–99205) carry slightly higher wRVU values than their established patient equivalents for the same level of MDM complexity. This reflects the additional work of an initial evaluation. The definition matters: a patient is new if they have not received any face-to-face professional service from you, or from any physician of the same specialty in your same group practice, within the past three years. For payers that still recognize consultation codes, a consult is valued like a new-patient visit, so the same higher-value tier applies; Medicare, which no longer pays consult codes, simply has you use the new or established office codes instead. The consultation chapter covers this in full.
A patient is "new" only if no provider in your group of the same specialty and subspecialty has seen them, face to face, in the past three years. Two things often trip people up. Seeing the patient at a different office location does not make them new again: the three-year rule follows the group and specialty, not the building. And a colleague's visit counts: if your partner in the same specialty saw the patient last year, the patient is established to you, even on your first time meeting them. (The exception, different subspecialty or taxonomy, is covered in the consultation chapter.)
Coding for Consultations: A Brief Note
Medicare eliminated payment for consultation codes (99241–99255) in 2010. For Medicare patients, what would have been a consultation is now billed as a new patient office visit (99202–99205) using the standard E/M codes. Most commercial payers still recognize consultation codes. If you see patients referred to you for specialist opinions, it is worth understanding whether your payer mix supports consultation code billing, and if so, whether your notes document the three elements that consultation codes require: a request from another provider, your rendered service, and a written report back to the requesting provider. This is covered fully in Chapter 19.
When in Doubt, Document More
The safest and most productive habit is to document your clinical thinking explicitly. If you are managing two chronic conditions, name them both. If you reviewed outside records or imaging, say so. If you discussed the risks of a treatment decision with the patient, document that conversation. This is not about writing longer notes for their own sake, it is about making sure your note tells the full clinical story of the encounter, which is both the right thing to do medically and the thing that protects you if you are ever audited.
Three Visits, Worked Through
The fastest way to make the level framework concrete is to walk through ordinary visits the way the table actually scores them. None of these is a procedure; all are the bread-and-butter cognitive visits that fill a primary care or specialty clinic day.
A straightforward upper respiratory infection
A healthy adult presents with three days of cough and congestion, no red flags. One self-limited problem, minimal data, low risk: you recommend supportive care and an over-the-counter decongestant. This is a level 3 established visit (99213). Note the trap from the medical-decision-making chapter: recommending an over-the-counter medication does not raise this to a level 4, because an over-the-counter drug is not prescription drug management. Coded honestly, it is a level 3, and that is correct.
The same cough, in a patient with poorly controlled diabetes
Now the same cough, but the patient has type 2 diabetes that has been running high, and you adjust their medication while you are at it. The picture changes. You are now addressing an acute illness alongside a chronic condition that is not at goal, and you are managing a prescription medication. That is two of the three elements at the moderate level: the problems addressed and the risk of the management plan. This is a level 4 (99214), and the documentation should make both the diabetes assessment and the medication change explicit, because that is what carries the level.
A new patient with several active problems
A new patient arrives with hypertension, hyperlipidemia, and new-onset atrial fibrillation, and you order an ECG and labs, start an anticoagulant, and arrange cardiology follow-up. Multiple chronic conditions, one of them newly diagnosed and serious, data ordered across more than one category, and high-risk medication management. This reaches a level 5 new patient (99205). The lesson across all three: the level is not about how long you spent or how hard it felt, but about what the note shows you addressed, reviewed, and decided.