Exact Age on the Date of Service — and the Code That Goes With It.
Preventive visit codes change at exact birthdays, and a claim billed with the wrong age band gets denied. Enter a date of birth and date of service to get age in years, months, and days, the matching 99381–99397 code, and when the patient moves to the next band.
- Calendar-accurate age, including leap-year birthdays
- The right preventive medicine code for new or established patients
- Medicare IPPE and Annual Wellness Visit pointers
Runs entirely in your browser — nothing you enter is stored or sent anywhere.
Date of birth → age on the date of service
Patient is…
Enter both dates to calculate.
Preventive codes are selected by the patient’s age on the date of service. Always confirm coverage — many commercial plans and Medicaid programs have their own preventive visit rules and frequency limits.
How It Works
Why Age Matters on a Claim
CPT preventive medicine services are split into seven age bands, separately for new (99381–99387) and established (99391–99397) patients. Payers check the code against the date of birth on file, so a patient who turned 18 last week needs 99395, not 99394. Age also drives vaccine codes, screening frequency, and pediatric dosing, which is why front desks and coders need an exact figure, not “about 17”.
Pediatrics
Months matter
Well-child schedules and many vaccines are set in months for the first years of life. The calculator shows total months and weeks alongside the years.
Adults
Band changes at 18, 40, and 65
The adult preventive codes change at the 18th, 40th, and 65th birthdays. The calculator shows the exact date of the next change.
Medicare
Different codes, different rules
Medicare doesn’t cover routine physicals (99387/99397). It covers the Initial Preventive Physical Examination (G0402) and the Annual Wellness Visit (G0438/G0439) instead.
Preventive medicine codes by age
| Age on date of service | New patient | Established patient |
|---|---|---|
| Under 1 year | 99381 | 99391 |
| 1–4 years | 99382 | 99392 |
| 5–11 years | 99383 | 99393 |
| 12–17 years | 99384 | 99394 |
| 18–39 years | 99385 | 99395 |
| 40–64 years | 99386 | 99396 |
| 65 years and over | 99387 | 99397 |
CPT® is a registered trademark of the American Medical Association. Code descriptors summarized; see the current CPT code set for full descriptors.
Questions
Frequently Asked Questions
How is age calculated for preventive visit codes?
By the patient’s age on the date of service. A patient becomes 18 on their 18th birthday, so a visit on that day uses the 18–39 code.
What happens with a February 29 birthday?
In non-leap years the calculator treats March 1 as the birthday, which is the common legal and practical convention.
What’s the difference between new and established patient codes?
A new patient hasn’t received professional services from the physician, or another physician of the same specialty in the same group, within the past three years. Otherwise use the established code.
Does Medicare pay for 99397?
No. Medicare doesn’t cover routine physical exams. Bill the IPPE (G0402) within the first 12 months of Part B coverage, then the Annual Wellness Visit (G0438 first, G0439 subsequent). Patients may be billed for a 99397 if they request a routine physical and have been informed it isn’t covered.
Can I bill a problem-oriented visit on the same day as a preventive visit?
Yes, if a significant, separately identifiable problem is addressed. Append modifier 25 to the problem-oriented E/M code and make sure the documentation clearly separates the two services.
Is my data stored?
No. The calculation runs entirely in your browser. Don’t enter names or other identifiers — a date of birth on its own is all the tool needs.
Sources
- [1]American Medical Association — CPT® code set
- [2]CMS — Medicare preventive services quick reference chart
- [3]Medicare.gov — Yearly “Wellness” visits
This is an independent planning tool built by MedVersify from published methodology. It is not an official CMS, payer, or clinical tool, and results are estimates — confirm decisions against your own reports, payer contracts, and clinical judgment.
Keep Going
BMI Calculator with Z68 Code
Adult BMI, CDC category, and the matching ICD-10-CM Z68 code for the same visit.
Open the toolMedical Billing Services
Coding and claim edits that catch age, sex, and frequency mismatches before claims go out.
See the serviceICD-10-CM FY2027 Code Changes
The new codes that took effect October 1, 2026, and a readiness plan for your practice.
Read the guideMore free tools
Coding Accuracy
Want Every Claim Checked Like This?
Our coders and claim edits catch age, modifier, and frequency errors before the payer does.