High volume, many small rules
Family medicine and internal medicine practices see more patients per day than most specialties, and each visit can combine a preventive service, a problem-oriented visit, screening, vaccines and in-office tests. Individually these are small claims; together they make up most of the practice’s revenue. Small, repeated errors — a missing modifier, a wellness visit billed under the wrong code, a vaccine sent to the wrong part of Medicare — add up quickly.
Preventive and problem visits on the same day
When a patient comes for a physical and also needs a significant, separately identifiable problem addressed, both can be billed: the preventive medicine code (99381–99397, by age and new or established patient) and an office E/M code (99202–99215) with modifier 25. The problem-oriented part must be documented separately enough to stand on its own, and patients should know that the problem visit may carry cost-sharing even when the preventive visit does not.
| Visit | Medicare | Most commercial plans |
|---|---|---|
| Welcome to Medicare (first 12 months of Part B) | G0402 (IPPE) | — |
| Annual wellness visit | G0438 (first), G0439 (subsequent) | — |
| Routine physical exam | Not a Medicare benefit — the patient is responsible (99381–99397) | 99381–99397 |
| Problem visit on the same day | 99202–99215 with modifier 25 | 99202–99215 with modifier 25 |
The Medicare annual wellness visit is a health-risk assessment and prevention plan, not a head-to-toe physical. Billing a routine physical as a wellness visit, or the reverse, is one of the most common primary care errors.
Care management between visits
Much of primary care happens between visits. Medicare and many other payers pay for this work when the requirements — consent, a care plan, time thresholds and documentation — are met.
- Chronic care management (99490, 99439, 99491; complex 99487, 99489) for patients with two or more chronic conditions, billed monthly by time.
- Principal care management (99424–99427) for one serious chronic condition.
- Transitional care management (99495, 99496) after a hospital or facility discharge: contact within two business days and a face-to-face visit within 7 or 14 days, depending on complexity.
- Advanced primary care management (G0556–G0558), a Medicare monthly bundle introduced in 2025 that cannot be combined with the care management codes it replaces for the same patient and month.
- Advance care planning (99497, 99498) and the G2211 add-on for visits that are part of ongoing, longitudinal care.
Vaccines, screening and in-office tests
Medicare covers influenza, pneumococcal and COVID-19 vaccines (and hepatitis B vaccine for patients at increased risk) under Part B, while most other vaccines for adults — shingles, for example — are covered under Part D and must be billed to the patient’s drug plan. Screening services have their own codes and frequency limits, and in-office laboratory tests need a CLIA certificate that matches the tests performed, with modifier QW on waived tests where payers require it.
Diagnosis coding and risk adjustment
Medicare Advantage and many commercial and ACA plans adjust payment to the plan based on the diagnoses documented each year. For the practice, that means chronic conditions should be assessed and documented at least annually with full ICD-10-CM specificity, and every diagnosis on a claim must be supported by the note. We code what the documentation supports and query providers when it is unclear; we do not add diagnoses to increase risk scores.