How to Bill Office E/M Codes 99202–99215 Using Medical Decision Making (MDM)

Providers choose office E/M codes 99202 through 99215 by one of two methods: medical decision making (MDM) or total time on the date of the visit. MDM works for any visit, while time works best for visits with long counseling or coordination. It rests on three elements, and the note has to meet two of the three at the chosen level. When the documentation shows that clearly, the level holds up in an audit.

This guide is for primary care physicians, internists and billing staff who want to code each visit at the level the work supports, no higher and no lower. It explains the MDM grid, how to choose between CPT 99213, 99214 and 99215, when time-based billing works better, how Medicare and other payers report prolonged services, and where modifier 25 fits.

Quick answer: Pick the office E/M level that matches two of three MDM elements: the problems addressed, the data reviewed and the risk of management. Use total time instead only when it supports a higher level. For extra time past 99205 or 99215, bill 99417 to payers that accept it and G2212 to Medicare.

How Office E/M Codes 99202–99215 Work

The office and other outpatient E/M family has four levels for new patients and five for established patients. A new patient has not received professional services from the same physician, or another physician of the same specialty in the same group, within the past three years. CPT 99211 is the exception in the established set, since it covers visits that may not need a physician, such as a nurse check, and it has no MDM level.

The CMS E/M services guide confirms that, for these office E/M codes, the provider selects the level by MDM or by total time. In both cases, the history and exam must be medically appropriate, but their extent does not change the code.

Medical Decision Making (MDM) for Office E/M Codes

Medical decision making (MDM) measures the thinking behind the visit. CMS E/M guidelines and the AMA CPT rules use the same three elements, and each has four levels. To reach a level, the note must meet or exceed two of the three.

1. Number and Complexity of Problems Addressed

Only problems the provider actually addresses count. A stable chronic illness, such as controlled hypertension, is a low-level problem. In contrast, a chronic illness with exacerbation, two or more stable chronic illnesses, or an acute illness with systemic symptoms reaches moderate. A severe exacerbation, or a threat to life or bodily function, reaches high.

2. Amount and Complexity of Data Reviewed and Analyzed

Data includes reviewing external notes, reviewing or ordering unique tests, getting history from an independent historian, independently interpreting a test billed by someone else, and discussing management with another clinician. Moderate data needs three items from the first group, or an independent interpretation, or a discussion with an outside clinician.

3. Risk of Complications of Patient Management

Risk comes from the treatment decision, not the diagnosis alone. For example, over-the-counter drug advice is low risk. Prescription drug management is moderate risk. Meanwhile, a decision about hospitalization, or drug therapy that needs intensive monitoring for toxicity, is high risk.

Several documentation gaps lead to MDM downgrades at audit:

• A problem list that names conditions but never states whether each is stable, worsening or new.
• Tests counted as data even though the provider only ordered them at a prior visit.
• A plan that says “continue current care” without naming the drug or decision behind it.
• Copied text from earlier notes that hides what the provider actually did today.

Pro tip: Write the assessment and plan so a reviewer can see all three elements: name each problem and its status, list the data you reviewed, and state the treatment decision. That one habit makes office E/M codes easier to defend at audit.

A few definitions also change the score. First, a chronic illness that is not at the patient’s treatment goal is not stable. Second, a test you order counts once, and its later review is part of that order. Third, social determinants of health that significantly limit diagnosis or treatment, such as being unable to afford a medicine, support moderate risk. Finally, a decision about hospitalization counts as high risk.

Choosing Office E/M Codes: CPT 99213, 99214 and 99215

The line between 99213 and 99214 deserves the closest attention. The examples below show how two of three elements set the level for office E/M codes.

• CPT 99213 (low MDM): One stable chronic illness, a review of one prior test result, and a decision to continue the same over-the-counter treatment.
• CPT 99214 (moderate MDM): Two stable chronic illnesses, or one with a flare, plus prescription drug management. The data element can stay low because problems and risk already meet moderate.
• CPT 99215 (high MDM): A chronic illness with a severe exacerbation, plus extensive data review, or a decision about hospitalization.

Note that prescription drug management alone does not make a visit 99214. The problems or the data must also reach moderate. For a deeper look at 99213, see our guide to established patient office visit requirements.

Time-Based Billing for Office E/M Codes

Time-based billing uses the total time the physician or other qualified health care professional spends on the patient on the date of the encounter. It includes both face-to-face and non-face-to-face work, such as reviewing records, ordering tests, documenting and talking with the family. However, it excludes work done by clinical staff, time spent on separately billed services, and work on a different date.

Time can fit visits with long counseling, care coordination or record review, where the MDM level would be lower than the effort. To bill by time, document the total minutes and what they covered. Then pick the code whose time threshold the total meets.

Watch out: Do not combine methods. Pick MDM or time for each visit, and make sure the note supports the method you used.

Prolonged Office E/M Codes: CPT 99417 vs. Medicare G2212

When a visit runs well past the highest level, payers let you report extra time, but CPT and Medicare count it differently. CPT 99417 adds each 15 minutes beyond the minimum time of 99205 or 99215, and you can report it only when you select the level by time.

Medicare does not accept 99417. Instead, it uses HCPCS G2212, which starts after the maximum time of the highest level. A Medicare contractor’s prolonged service code page lists the thresholds: G2212 applies once 99215 reaches 69 minutes, or once 99205 reaches 89 minutes. Therefore, set up separate payer rules in your billing system so the right code and threshold apply to each claim.

Modifier 25 With Office E/M Codes

Modifier 25 applies when the provider performs a significant, separately identifiable E/M service on the same day as a procedure or another service. In a primary care office, it can apply when a problem visit happens on the same day as a preventive visit, a joint injection or a minor procedure. The E/M level must rest only on the separate work, not on the work that belongs to the procedure.

Medicare also limits the visit complexity add-on code G2211 when the base visit carries modifier 25. Since January 1, 2025, Medicare allows G2211 with modifier 25 only when the other service is an annual wellness visit, vaccine administration or a Part B preventive service.

How to Avoid Medicare Audit Risk With Office E/M Codes

Auditors look for patterns, such as one provider who bills far more 99215 visits than peers or a practice where every visit is 99214. The goal is accuracy, so defensive undercoding is also a problem, because it loses revenue the work supports.

Step 1Build Templates Around the Three Elements

Give each note a clear problem list, a data section and a plan with the treatment decision. As a result, the level becomes easy to defend.

Step 2Audit a Sample Every Quarter

Next, review ten to fifteen notes per provider each quarter. Compare the billed level with the level the documentation supports, and share the results.

Step 3Track Level Distribution by Provider

Then compare each provider’s mix of office E/M codes with their own history and with peers in the same specialty. Investigate sudden shifts in either direction.

Step 4Respond Quickly to Payer Requests

Finally, send complete records and a clear summary when a payer asks for documentation. Our article on preventing payer audit recoupments covers that process in detail.

Common Errors With Office E/M Codes

Watch for four mistakes when you review a sample of visits. Each one either lowers payment or invites a payer request, so check for them in every quarterly audit.

• Defensive downcoding. Some providers pick 99213 even when the note supports moderate MDM. For example, two stable chronic illnesses plus prescription drug management meet two of the three elements, so the visit supports 99214.
• Counting time from another day. Total time counts only on the date of the encounter. Chart review the night before does not add to the level.
• Mixing up new and established patients. A patient is new only if no physician of the exact same specialty and subspecialty in the same group has provided a professional service to them in the past three years.
• Cloned notes. Text copied from an earlier visit does not show today’s work, and an auditor may disregard it. Instead, record the problems, data and plan for this visit.

Example: Choosing Office E/M Codes by MDM

Consider a hypothetical established patient with type 2 diabetes and high blood pressure. The internist reviews recent lab results, finds the A1C above goal, and adds a second prescription medicine. She also notes that blood pressure stays controlled on the current dose.

Problems reach moderate, because the visit addresses two chronic illnesses, one of them not at goal. Risk reaches moderate, because she manages a prescription drug. Data reaches only low. Since two of three elements meet moderate, the visit supports CPT 99214. If the internist had spent 45 minutes on the visit that day, time would also support 99214 and would not change the code.

When to Get Help With Office E/M Coding

Office E/M codes are a core revenue source in primary care, and small errors repeat across thousands of visits. Our professional medical billing and coding services include E/M audits, provider education and payer-specific rules for prolonged services and modifiers.

Frequently Asked Questions