In nearly every state, no — a dental hygiene diagnosis sits outside what a hygienist is listed to do.
The ADHA's Practice Act Overview (8.24.26 update) lists Dental Hygiene Diagnosis as permitted hygienist scope in just 6 of the 51 jurisdictions it tracks: Arizona, California, Colorado, Indiana, Maine, and Oregon.
It's one of the tightest rows on the chart — the supervision levels attached to those six states range from a dentist's prior authorization to a hygienist's own direct-access determination.
The short answer
Dental Hygiene Diagnosis is one of the tightest rows on the ADHA's entire chart.
The Practice Act Overview (8.24.26 update) lists it as permitted hygienist scope in only 6 of the 51 jurisdictions it tracks: Arizona (General), California (General), Colorado (Direct Access), Indiana (Direct and Direct Access, as two separate settings), Maine (Direct Access), and Oregon (Collaborative Practice and Direct, as two separate settings).
The other 45 jurisdictions show no listed supervision level for this specific function.
That 6-state footprint puts diagnosis among the chart's rarest permitted functions — tighter than treatment planning (12 of 51) and close to the chart's absolute floor, Botox (3 of 51) and suture placement (4 of 51).
It is a real, separately tracked scope question — not a synonym for the clinical assessment that leads up to it.
Informational only — confirm with your state board
What "dental hygiene diagnosis" means on this chart — and what it isn't
On the ADHA chart, Dental Hygiene Diagnosis is its own row, distinct from two neighbors it's easy to blur together: Dental Hygiene Assessment (gathering the clinical findings — probing depths, radiographic findings, health history) and Treatment Planning (proposing the sequence of care that follows).
Diagnosis is the step in between: reaching a conclusion about a patient's periodontal or oral condition from the assessment findings, before any plan is proposed.
The chart tracks all three as separate functions with their own supervision levels, so a listed permission on one doesn't carry over to another.
This is also a narrower question than the general scope limit covered in what a dental hygienist can't do — that article covers dentist-only diagnosis broadly across states; this one covers only the Dental Hygiene Diagnosis chart row specifically, in the six states where the chart lists it as permitted at all.
Reading the supervision levels
Four different codes appear across this row's six listed jurisdictions.
Each comes from the chart's own legend:
- G — General Supervision: the dentist authorizes the service beforehand but need not be present.
- A — Direct Access: the hygienist can provide the service based on their own determination, without specific authorization.
- D — Direct Supervision: the dentist needs to be present.
- CP — Collaborative Practice: the hygienist may practice without supervision, under a collaborative agreement with a licensed dentist.
- "-" — not listed as a permitted function in the chart. That isn't the same as prohibited — it means the chart records no permitted supervision level for that state, so confirm directly with the board.
Indiana's cell reads D/A and Oregon's reads CP/D — each is two separate listed settings (the chart distinguishes private and public practice), never a range and never blended into one answer.
Quote each cell exactly as the chart lists it.
Where hygienists have a listed role in dental hygiene diagnosis, by state
Quoting the chart as written, here is the supervision level listed for every jurisdiction.
Six list a level at all; the remaining 45 show no listed supervision level for this specific function.
| State | Dental Hygiene Diagnosis supervision level (ADHA chart) |
|---|---|
| Alabama | - |
| Alaska | - |
| Arizona | G |
| Arkansas | - |
| California | G |
| Colorado | A |
| Connecticut | - |
| Delaware | - |
| District of Columbia | - |
| Florida | - |
| Georgia | - |
| Hawaii | - |
| Idaho | - |
| Illinois | - |
| Indiana | D/A |
| Iowa | - |
| Kansas | - |
| Kentucky | - |
| Louisiana | - |
| Maine | A |
| Maryland | - |
| Massachusetts | - |
| Michigan | - |
| Minnesota | - |
| Mississippi | - |
| Missouri | - |
| Montana | - |
| Nebraska | - |
| Nevada | - |
| New Hampshire | - |
| New Jersey | - |
| New Mexico | - |
| New York | - |
| North Carolina | - |
| North Dakota | - |
| Ohio | - |
| Oklahoma | - |
| Oregon | CP/D |
| Pennsylvania | - |
| Rhode Island | - |
| South Carolina | - |
| South Dakota | - |
| Tennessee | - |
| Texas | - |
| Utah | - |
| Vermont | - |
| Virginia | - |
| Washington | - |
| West Virginia | - |
| Wisconsin | - |
| Wyoming | - |
Source: ADHA Dental Hygiene Practice Act Overview, 8.24.26 update.
A "-" means the function isn't listed as permitted in that state's row — not that it's necessarily prohibited.
How this compares to other functions on this chart
Dental Hygiene Diagnosis's 6-of-51 footprint sits near the tight end of the ADHA chart.
It's listed in more jurisdictions than Botox (3 of 51) and placing sutures (4 of 51), but in fewer than treatment planning (12 of 51) or lasers (15 of 51) on the same chart — and far fewer than broadly permitted functions like administering nitrous oxide (34 of 51).
Don't assume permission for one function on this chart implies permission for another — the ADHA lists each one separately, and this article covers only the Dental Hygiene Diagnosis row.
Confirm your state's exact rule
A "-" on this chart means the function isn't listed as permitted in that state's row — it does not mean the state prohibits it outright, only that the chart doesn't record an authorized supervision level there.
Even in the six listed states, confirm exactly what the term covers in practice, since practice acts and their interpretation change over time.
Start with your state dental board's practice act, and treat this chart and this article as a snapshot dated to 8.24.26 rather than a permanent rule.
For the rest of what a hygienist can and can't do, see our full breakdown of hygienist scope limits.
This article is general information, not legal or clinical advice. Scope-of-practice and supervision rules vary by state and change over time — confirm current requirements with your state dental board.