A 54-year-old patient books her annual physical for the second week of February. Ten minutes in, she mentions that her knee has been swelling for a month, and the visit becomes a knee exam, an X-ray order and a referral. The physician documents everything in one note and the biller sees a 99396. The knee work is unbilled. Or the biller adds a 99213 with modifier 25, the payer applies the deductible that reset in January, and the patient calls two weeks later angry that her "free physical" cost $140.
Both outcomes are common, and both are avoidable. This time of year is when they happen most, because deductibles have just reset and the schedule is full of wellness visits. The rules are not complicated. The execution is where practices lose money or patients, and sometimes both.
Key takeaways
- A preventive visit (99381 to 99397), a Medicare Annual Wellness Visit (G0438, G0439) and a problem visit (99202 to 99215) are three different services. Traditional Medicare does not pay for the first one.
- A significant, separately identifiable problem addressed at a preventive visit is billed as its own E/M with modifier 25 on the problem code, leveled on the problem work alone.
- Keep the diagnoses separate: Z00.00 or Z00.01 on the preventive line, the problem diagnosis on the problem line.
- The patient hears about the split three times, at scheduling, at check-in and in the room, or the practice ends up writing off the problem visit.
- A modifier 25 rate of 25 to 40 percent on preventive visits with clear documentation is normal in primary care; 90 percent draws audits.
The three kinds of visit that get confused
| Visit | Codes | Who covers it | What it is |
|---|---|---|---|
| Preventive medicine visit ("annual physical") | 99381 to 99397, by age and new or established | Most commercial plans at no cost share under the ACA preventive rules; traditional Medicare does not cover these codes | Age-appropriate history, exam, counseling, risk factor reduction, ordering of screenings |
| Medicare Annual Wellness Visit | G0438 (first), G0439 (subsequent); G0402 for the Welcome to Medicare visit in the first 12 months | Medicare Part B, no deductible or coinsurance | Health risk assessment, personalized prevention plan, screening schedule, cognitive assessment; no hands-on physical exam required |
| Problem-oriented visit | 99202 to 99215 | All payers, subject to deductible and copay | Evaluation and management of a complaint or chronic condition |
The first misunderstanding is that Medicare pays for an annual physical. It does not. A traditional Medicare patient who wants a head-to-toe physical exam with no complaint is asking for a non-covered service, and the practice needs an Advance Beneficiary Notice on file before billing the patient. What Medicare covers is the wellness visit, which is a different service with a different structure. Many practices combine the two in one appointment and bill only the G code, which is fine as long as everyone understands that the exam portion is being given away.
The same-day rule
CPT and Medicare both allow a preventive service and a problem-oriented E/M on the same day when the problem work is significant and separately identifiable. The problem visit carries modifier 25. The preventive code does not. The level of the problem visit is selected on the problem work alone: the medical decision making or time spent on the knee, not on the whole visit.
What "significant" means in practice: a new complaint that requires its own history, exam and plan, or a chronic condition that needs adjustment. It does not mean refilling a stable blood pressure medication mentioned in passing. If the physician would not have billed a 99212 for the problem work on its own, it does not qualify for a separate code.
Documentation should make the split visible. We recommend a separate heading in the note, "Problem addressed at this visit", with its own assessment and plan. When a payer audits modifier 25 on preventive visits, and several large commercial payers do, that heading is the difference between an upheld claim and a refund. If the clinician is leveling by time, the note should state the time spent on the problem separately from the preventive work, because the preventive time cannot be counted twice.
Diagnosis coding
The preventive line carries the preventive diagnosis: Z00.00 (encounter for general adult medical examination without abnormal findings) or Z00.01 (with abnormal findings), Z00.129 or Z00.121 for children. The problem line carries the problem diagnosis, for example M25.461 for right knee effusion. Do not put the problem diagnosis in the first position on the preventive line; many payers will reprocess the whole visit as a problem visit and apply cost sharing to all of it.
For Medicare, G0439 pairs with Z00.00 or Z00.01 and the problem visit 99213-25 pairs with the problem diagnosis. Screening services billed at the same visit have their own codes: G0444 for the annual depression screening, G0442 for alcohol misuse screening, and the various screening lab and imaging orders. One detail that trips people: G0444 is not separately payable with the first AWV (G0438) because depression screening is already a required element of that visit; it pays with the subsequent AWV.
Where the patient conversation goes wrong
Patients do not distinguish between preventive and problem care. They booked a "checkup", and they expect the whole thing to be covered. The bill arrives with a deductible amount and the practice takes the blame for the payer's benefit design. In our experience the practices with the fewest complaints do three things:
- Scheduling asks, "Is there anything specific you want the doctor to look at?" If yes, the scheduler explains that a problem addressed at a preventive visit may be billed separately and may be subject to the deductible.
- The check-in packet includes a one-paragraph explanation of preventive versus problem services, signed by the patient. This is a communication tool, not a legal document, and it works.
- The clinician says it out loud in the room: "We can look at the knee today, and I want you to know that part of the visit is billed separately from the physical." Patients who hear it from the physician almost never dispute the bill.
Some practices go one step further and offer the patient a choice: address the problem today as a separate service, or book a problem visit next week. Either answer is fine. What matters is that the patient chose, and that the note or the check-in form records it.
A worked example
An established 54-year-old commercial patient has a preventive visit (99396) and the knee complaint is evaluated with a focused history, exam, X-ray order and an orthopedic referral, coded 99213-25. Say the practice's contracted allowable is $210 for 99396 and $105 for 99213. The payer pays the 99396 at 100 percent under preventive benefits. The 99213 is applied to the patient's unmet deductible, so the patient owes $105. The practice collects $315 in total, and if the scheduler and physician both mentioned it, the $105 arrives without a phone call. If nobody mentioned it, the practice spends 40 minutes on the complaint, and often writes it off to keep the patient.
Now the same visit for a traditional Medicare patient. G0439 pays about $135 under the 2024 national fee schedule, adjusted by locality, with no patient cost sharing. The 99213-25 pays around $90 with 20 percent coinsurance after the Part B deductible, which for 2024 is $240. In February most patients have not met it, so the patient owes the full allowed amount for the problem visit. Multiply the unbilled problem visit by 300 wellness visits a year and a two-physician practice is leaving somewhere around $25,000 in allowed charges on the table.
Common mistakes we see in audits
- Billing 99397 to traditional Medicare and writing off the denial instead of having an ABN and billing the patient, or instead of billing the AWV that was actually covered.
- Adding modifier 25 to the preventive code rather than the problem code.
- Selecting the problem visit level based on the total time of the combined visit.
- Billing a problem visit for a stable chronic condition that was only listed, not managed.
- Forgetting that G0438 can be billed only once per lifetime; a second "initial" AWV denies.
- Never billing the problem visit at all because the physician did not want to "upset the patient". Multiply that by 300 wellness visits a year and it is real money.
Questions we hear
Can we bill an AWV and a preventive physical on the same day for a Medicare Advantage patient?
Some Medicare Advantage plans cover a routine physical (99397) as a supplemental benefit alongside the AWV. Check the plan's benefit; many do, and it changes the answer to the patient's question about cost.
Is modifier 25 on a preventive visit a red flag?
Only when the pattern is extreme. A practice billing a problem visit on 90 percent of preventive visits will get letters. A rate of 25 to 40 percent with clear documentation is what we see in well-run primary care.
What if the problem was found during the exam, not raised by the patient?
Same rule. If the finding leads to separate, significant work, it is billable with modifier 25 and Z00.01 on the preventive line. The Revelrex billing team reviews preventive and problem claims together at charge entry for exactly this reason, and our training courses include a session on same-day E/M rules with real claim examples.
What to do this week
- Run a report of preventive codes (99381 to 99397, G0438, G0439) billed since January 1 and count how many had a same-day problem E/M. If the rate is under 10 percent, ask the clinicians whether problems are going unbilled.
- Add the scheduling question and the one-paragraph check-in explanation before the end of the week, and show both to the front desk in a five-minute huddle.
- Add the "Problem addressed at this visit" heading to the preventive visit template in the EHR.
- Pull every 99397 billed to traditional Medicare in the last year, check whether an ABN exists, and decide what to do with the write-offs.
- Give the billers the diagnosis pointer rule in writing: Z code on the preventive line, problem code on the problem line, never the other way around.
