E/M Coding in 2026: The Changes You Must Know

Evaluation and Management (E/M) coding has been through more change in the past five years than in the previous two decades. The 2021 and 2023 AMA revisions fundamentally changed how office and outpatient E/M codes are selected — and 2026 brings further refinements that every provider and coder must understand to avoid underbilling, overbilling and compliance risk.

A Quick Recap: How E/M Coding Changed

Before 2021, E/M code selection was driven primarily by the number of elements documented in the History, Examination and Medical Decision Making (MDM) components. Since 2021, the rules have shifted to allow code selection based on either Medical Decision Making complexity or total time — removing the old history and exam requirements for office visits.

This was a major win for providers — but only if your documentation and coding practices were updated accordingly. Many practices are still coding under the old rules and consistently underbilling as a result.

The 2026 Updates You Need to Know

Clarifications to Medical Decision Making Criteria

The 2026 guidelines provide additional clarity on what qualifies as "moderate" versus "high" complexity MDM — particularly around:

• The definition of an "independent interpretation" of a test result (versus simply reviewing a report)
• When prescription drug management qualifies for moderate vs high MDM
• How social determinants of health factor into MDM complexity
• Clearer criteria for when a condition is considered "chronic with exacerbation"

Time-Based Billing Updates

Total time on the date of the encounter continues to be a valid basis for E/M code selection. The 2026 updates clarify which activities count toward total time, including:

• Time spent reviewing external records before the visit
• Care coordination activities performed on the date of the visit
• Counselling and education time with the patient or family
• Documentation time completed on the day of the encounter

Split and Shared Visit Rules

When a visit is shared between a physician and an NPP (nurse practitioner or physician assistant), the 2026 rules provide updated guidance on when the physician versus the NPP should be listed as the billing provider — and how this affects reimbursement rates under Medicare.

Common E/M Coding Mistakes to Avoid

1. Defaulting to 99213 for all established patient visits out of habit rather than reviewing MDM
2. Not documenting total time when a time-based code would support a higher level
3. Failing to document the complexity of problems addressed — not just the diagnosis
4. Not counting prescription drug management toward MDM when it qualifies
5. Underdocumenting data reviewed — external records, test interpretations and discussions with other providers all count
6. Using the old 1997 documentation guidelines when the new MDM criteria would support a higher level of service

How to Audit Your E/M Coding

Pull a random sample of 20 charts from the past 3 months and re-code them using the current 2026 MDM guidelines. If you find that your original codes were consistently one level lower than what the documentation supports, you have a systematic undercoding problem that is costing your practice real money every single day.

At Zenith Coding Nexus, we conduct regular E/M coding audits for all our clients as a standard part of our compliance and revenue optimisation service — at no additional charge.