Insurance · Updated 2026-09-08 · 4 min read

At what age does D1120 become D1110?

Two federal plans state it identically: age 13 and under bills as D1120 and age 14 and over as D1110. Medicaid programs split at 12, 13 or 14 instead.

On the plans that publish the boundary, a patient becomes an adult for the cleaning code at 14: age 13 and under is processed as D1120 (prophylaxis, child) and age 14 and over as D1110 (prophylaxis, adult). Two federal carriers print that sentence word for word. It is not a universal rule — state Medicaid programs draw the same line at 12, 13 or 14, and plenty of commercial plans publish no boundary at all. As of September 2026, 5.5% of MetLife's D1110 lines, 2.6% of Delta Dental's and 1.0% of UnitedHealthcare's came back paying $0 with an age-limitation reason, which is what a child billed on the adult code looks like on the remittance.

What we measured

Every remittance line billed under D1110 to that carrier, all dates, with the share paying $0 for an age-limitation reason. Measured September 2026 across 37 practices and more than 170 payers; Delta Dental member companies are pooled. An age denial on an adult cleaning code is almost always a child billed on the wrong code rather than a coverage gap — the plan covers the cleaning, on D1120.

What the carriers' own policies say

Two federal programs state the boundary identically. The UnitedHealthcare FEDVIP dental plan, 2026 OPM brochure:

"D1110 Prophylaxis - adult - (Age 13 and under will be processed as D1120 Prophylaxis - child) - Limited to 2 times per calendar year D1120 Prophylaxis - child - (Age 14 and over will be processed as D1110 Prophylaxis - adult) - Limited to 2 times per calendar year"

BCBS FEP Dental, 2026 benefit brochure, in the same words:

"Age 13 and under will be processed as D1120 Prophylaxis - child, and age 14 and over will be processed as D1110 Prophylaxis - adult."

Delta Dental of Tennessee's carrier policy states the other side of the same boundary: adult prophylaxis is not allowed for members under 14.

Public programs put the line elsewhere. Alabama Medicaid's provider policy pairs D1110 with ages 13 and up and D1120 with ages 3 to 12. CareSource Georgia states "D1110 adult prophy: age 13 and older." Missouri Medicaid runs D1110 from 13 and D1120 from 0 to 12. Pennsylvania's Medical Assistance bulletin of June 5, 2024 is the outlier in the other direction:

"D1120 Prophylaxis – child … 1 visit per 180 days, per patient (Under 12 years of age only)"

UnitedHealthcare's Community Plan splits at 14, with D1110 covering ages 14 to 20 and D1120 age 13 and under.

Why it depends on the plan

MetLife has the highest adult-prophylaxis age-denial rate in the measured data, at one line in eighteen, but MetLife does not publish its own child-to-adult boundary in any carrier-wide or network document reviewed here. Its federal brochure lists both codes with frequencies and no age note, and its carrier-wide policy page deliberately publishes no typical frequencies. So the honest statement is that MetLife enforces a boundary and does not say what it is. Ask, per plan; do not carry the federal 14 onto a MetLife commercial plan on the strength of this number.

The rest of the variation is structural. Federal plans state the rule because the OPM brochure prints a payment schedule per code. Commercial plans mostly leave it in the plan document and the claims system. Medicaid programs state it on the fee schedule, where it doubles as the age range the code may be billed in at all.

And the boundary is not always a denial. Ameritas remaps rather than denies: an adult cleaning billed on a child is re-coded to D1120 and paid, so the same clinical error produces a paid line at one carrier and a $0 line at another. Both are the same rule. Only one of them is visible on the day.

What to do

• Record the boundary age per plan, as the oldest age still billed on D1120, and let the practice management system drive the code off the patient's date of birth rather than the hygienist's habit.
• On an age denial for D1110, do not appeal. Rebill on D1120. The plan covers the cleaning; the code was wrong.
• Watch the year the patient crosses over. A 13-year-old at the January recall and 14 at the July recall changes code mid-year, and a plan with two cleanings a calendar year counts both toward the same limit.
• Where the plan remaps rather than denies, check the paid amount as well as the paid status. A child cleaning usually carries a lower allowed amount, so the patient portion moves even when nothing was refused.
• On Medicaid patients, read the fee schedule's age range for both codes rather than assuming 14. Programs in this evidence split at 12, 13 and 14.

Numbers last refreshed September 2026.

All articles · Kaylie