- G0438 is the initial AWV - billable once per lifetime, only after the beneficiary has had Medicare Part B for more than 12 months.
- G0439 is the subsequent AWV - billable annually, at least 11 full months after the last AWV.
- The first 12 months of Part B use the IPPE (Welcome to Medicare visit), G0402 - not an AWV.
- The AWV is not a head-to-toe physical and carries no copay or deductible; the usual diagnosis is Z00.00.
- A separate, medically necessary E/M (e.g., 99213-99215) can be billed the same day with modifier 25.
The Medicare Annual Wellness Visit is one of the most valuable and most mis-billed preventive services in primary care. The codes look simple, but the frequency rules are unforgiving, and a single sequencing error converts a clean preventive claim into a frequency denial. The AWV is a structured, preventive planning visit built around a health risk assessment and a personalized prevention plan - it is explicitly not the routine head-to-toe annual physical Medicare does not cover.
Three codes, one timeline: G0402, G0438, G0439
Medicare's wellness benefit unfolds across a beneficiary's enrollment, and each phase has its own code. The IPPE, or Welcome to Medicare visit (G0402), is available only within the first 12 months of Part B enrollment. After the beneficiary has had Part B for more than 12 months, the first AWV is billed with G0438. Every AWV after that uses G0439.
| Code | Service | Eligibility / Frequency | Cost-Sharing |
|---|---|---|---|
| G0402 | Initial Preventive Physical Exam (IPPE) - Welcome to Medicare | Within the first 12 months of Part B; once per lifetime | No copay/deductible |
| G0438 | Annual Wellness Visit - initial | Once per lifetime, after more than 12 months of Part B | No copay/deductible |
| G0439 | Annual Wellness Visit - subsequent | Annually; at least 11 full months after the last AWV | No copay/deductible |
One rule trips up even experienced billers: do not bill G0438 or G0439 within 12 months of billing G0402 for the same patient. Medicare measures eligibility by month - a patient becomes eligible again on the first day of the same calendar month the following year.
G0438: the once-per-lifetime initial AWV
G0438 is reported exactly once in a beneficiary's lifetime. It requires a health risk assessment, a review of medical and family history, a list of current providers, measurement of routine vitals, detection of cognitive impairment, and a written personalized prevention plan. Because it is once-per-lifetime, the single biggest G0438 error is billing it when the patient has already had an AWV - that visit should have been G0439.
G0439: the annual subsequent AWV
G0439 is the yearly follow-up. It updates the health risk assessment, the prevention plan, and the screening schedule. The timing gate is the at-least-11-full-months rule: a visit performed even a few weeks early will deny for frequency. Confirm the date of the last AWV before scheduling.
Z00.00 and the same-day E/M with modifier 25
The AWV is a preventive service, so the claim should carry a preventive diagnosis - most commonly Z00.00 (encounter for general adult medical examination without abnormal findings). Do not lead the AWV claim with a problem-based diagnosis such as I10 or E11.9.
When the provider also addresses a significant, separately identifiable medical problem during the same encounter, a problem-oriented E/M (such as 99213-99215) may be billed in addition to the AWV - with modifier 25 appended to the E/M code. The E/M must have its own documentation and problem diagnosis, and standard Part B cost-sharing applies to the E/M portion even though the AWV itself does not.
Common denials and how to fix them
| Denial Reason | Root Cause | Fix |
|---|---|---|
| Frequency - AWV too soon | Billed before 12 months of Part B, or less than 11 full months after the last AWV | Verify Part B start date and last AWV date; schedule on or after the eligible calendar month |
| Wrong AWV code | G0438 billed when a prior AWV exists | Use G0438 only for the first-ever AWV; all subsequent visits are G0439 |
| IPPE/AWV overlap | AWV billed within 12 months of a G0402 IPPE | Allow a full 12 months between the IPPE and the first AWV |
| Routine physical denial | AWV confused with a non-covered annual physical | Document AWV components; do not bill a routine head-to-toe physical to Medicare as covered |
| Same-day E/M denied | Missing modifier 25 on the problem-oriented E/M | Append modifier 25 to the E/M and ensure separate documentation and a problem diagnosis |
Frequently asked questions
G0438 is the initial AWV, billable once per lifetime after the beneficiary has had Part B for more than 12 months. G0439 is the subsequent AWV, billable annually thereafter (at least 11 full months after the prior AWV). If any prior AWV exists, use G0439, not G0438.
Only after the beneficiary has had Part B for more than 12 months. The first 12 months are covered by the IPPE (G0402). Billing G0438 before the 12-month mark - or within 12 months of a G0402 - leads to a frequency denial.
The usual primary diagnosis is Z00.00 (encounter for general adult medical examination without abnormal findings). Avoid leading the AWV claim with a problem-based diagnosis, which can trigger a denial.
Yes. If you provide a significant, separately identifiable E/M service (such as 99213-99215), bill it in addition to the AWV by appending modifier 25 to the E/M code. Standard Part B cost-sharing applies to that E/M portion.
No. The AWV (G0438 and G0439) has no copay and no deductible when billed correctly as a preventive service. Any separately billed same-day problem-oriented E/M is subject to standard Part B cost-sharing.