Most undercoded notes are level 4 visits documented like level 3 visits. The difference is usually one sentence.
Under the 2021 framework, the level comes from medical decision making unless time is higher. MDM has three categories: problems addressed, data reviewed and analyzed, and risk of the management decisions. The visit level is the level that at least two of the three categories reach. That is the whole rule; everything else is knowing what lands in each tier.
First: one chronic condition with exacerbation or progression (diabetes above goal, worsening knee arthritis failing conservative care) makes problems moderate. Second: two or more stable chronic conditions together also make problems moderate. Third: prescription drug management (starting, adjusting, or deliberately continuing a prescription) makes risk moderate. Any two of those in the same note is a 99214. In practice the most common documented pair is "chronic problem not at goal" plus "medication managed."
For an established patient, 30 to 39 total minutes on the date of service supports 99214 by time regardless of MDM, and 20 to 29 supports 99213. Total time excludes any separately reported procedure and must be documented as an exact number of minutes, not a range.
The work is usually done and the sentence is missing: the second chronic problem reviewed but not written down, the refill decision made but never stated as management, the worsening never named as worsening. Write what you actually decided and the level follows.
Paste a real note into the E/M Coding Assistant and it will show which tier each category reached, why, and the exact sentence that would honestly support the next level when the work was done. The Five Note Audit finds your personal undercoding pattern across five notes.