Primary care billing runs on E/M coding for sick and follow-up visits, a separate set of preventive/wellness codes for annual exams, and increasingly, chronic care and transitional care management codes that pay for work done outside the face-to-face visit.
Why This Specialty Is Billing-Complex
Since the 2021 E/M guideline overhaul, office visit levels are selected by either total time or medical decision-making, and practices that still document to the old history/exam-heavy templates often under- or over-code visits relative to what the note actually supports. Preventive visits and problem-oriented visits also have separate billing rules, and combining the two in one encounter requires modifier 25 and clear separation in the note.
Common CPT, ICD-10 & HCPCS Codes
- CPT 99202-99215 — office/outpatient E/M, new and established patient
- CPT 99381-99397 — preventive medicine visits, by age group
- HCPCS G0438/G0439 — Medicare annual wellness visit, initial and subsequent
- CPT 99490 — chronic care management, 20 minutes non-face-to-face per month
- CPT 99495/99496 — transitional care management, moderate/high complexity
Documentation Standards
For E/M visits billed by medical decision-making, the note needs to show the number and complexity of problems addressed, the data reviewed, and the risk involved; for visits billed by time, the total time spent on the date of the encounter must be stated explicitly. When a preventive visit and a problem-oriented visit happen together, the note should document each separately so modifier 25 is clearly supported.
Common Denial Reasons & How to Prevent Them
- E/M level denials or downcoding when documentation does not support the medical decision-making or time billed
- Denials for billing a Medicare annual wellness visit using preventive E/M codes instead of G0438/G0439
- Missing modifier 25 when a preventive and a problem-oriented visit are billed together
- Denials for chronic/transitional care management codes without the required non-face-to-face time log
Tools That Help
ICD-10-CM Search · Denial Code Lookup · Modifier/POS Reference · RCM Calculators · NPI Lookup