Dental hygienist license: NBDHE & renewal

What is a dental hygienist license?

A dental hygienist license is a state's legal permission to practice as a registered dental hygienist (RDH), issued by that state's dental board once you graduate from an accredited dental hygiene program, pass the national written board, and pass a clinical exam the state accepts. You can't clean teeth, take radiographs, or work under a dentist's supervision without one. The board that issues the license also sets its renewal rules and can suspend or revoke it for cause.

The license is mandatory in every state, and RDH is the title it grants. A separate certificate, such as a local anesthesia or nitrous oxide permit, is an add-on some states let you earn on top of the license, and it never replaces the license itself. If you assist the dentist rather than practice hygiene, that's a different role with its own credential; the dental assistant (RDA) guide covers that path.

How RDH licensure works: accredited program, the NBDHE, and a clinical exam

You get a dental hygienist license in four steps: graduate from an accredited dental hygiene program, pass the National Board Dental Hygiene Examination, pass a clinical exam your state accepts, then apply to the state dental board. The board checks your education, runs a background check, and issues the license once both exams are on file. Most states also make you pass a jurisprudence exam on state dental law before they license you.

The program has to be accredited by the Commission on Dental Accreditation (CODA), the ADA body that accredits dental hygiene education. Most RDHs earn an associate degree, which usually takes about three years once you count prerequisite coursework, though bachelor's-level programs exist too. Graduating from a CODA-accredited program is what makes you eligible for the national board and, in almost every state, for the license itself.

The NBDHE: the national written exam

The National Board Dental Hygiene Examination (NBDHE) is the written, computer-based exam that tests dental hygiene knowledge, and passing it is a licensure requirement in every US state. It's given under the Joint Commission on National Dental Examinations (JCNDE), an agency of the American Dental Association, and delivered at Pearson VUE test centers.

The NBDHE has 350 questions across two sessions: a 200-item discipline-based component and a 150-item case-based component built around 7 to 8 patient cases. It runs about 9 hours in total, and results are reported as pass or fail rather than a numeric score, so it counts the same in any state. The examination fee is $600 for graduates and students of a CODA-accredited program, and that fee covers reporting your result to three licensing jurisdictions if you name them when you apply (JCNDE NBDHE Candidate Guide, 2026). Candidates from a program that isn't CODA-accredited pay a separate $435 processing fee. JCNDE has said the NBDHE test specifications are due for an update around October 2026, so check the current blueprint against your test date.

The clinical exam

Every state also wants proof of clinical skill, which you show by passing a hands-on exam from a regional testing agency the state accepts. The most widely accepted one is the ADEX Dental Hygiene Examination, administered by the American Board of Dental Examiners, the organization formed when CDCA-WREB-CITA and ADEX finalized their merger in August 2025.

The ADEX dental hygiene exam has moved to a manikin-based format, so candidates scale and probe on a standardized manikin (the CompeDont tooth) instead of bringing a live patient to the chair. It pairs that clinical portion with a computer-based diagnostic component. CRDTS and SRTA are other agencies whose exams some states accept, and a handful of states run or recognize their own clinical route. Your state board's page lists which exams it takes, so confirm the accepted agency before you register and pay.

License renewal

Most states renew a dental hygienist license on a 1- or 2-year cycle, and every renewal pairs a fee with continuing education (CE) hours. You renew through the state dental board, pay the renewal fee, and attest that you completed the CE the state requires for the period. Let the license lapse and you can't practice until you reinstate it.

CE is where states differ most. Washington asks for 15 clock hours a year. Pennsylvania wants 20 hours per 2-year cycle, including 2 hours on recognizing and reporting child abuse. Colorado sets 30 hours per 2-year period, and Wisconsin sets 12 hours per 2-year period (2026). States also require specific topics, such as infection control, CPR or basic life support, opioid prescribing awareness, or ethics. Because both the hours and the mandatory topics change from state to state, read your own board's renewal page before each cycle.

How requirements differ by state

The dental hygienist license is a state credential, so the clinical exam it accepts, the fee, the renewal cycle, the CE hours, and the scope of practice all change when you cross a state line. The NBDHE is national, and nearly every other requirement is set by the state.

Practical differences you'll run into: states accept different clinical exam agencies, so a passing result in one state doesn't automatically satisfy the next; renewal runs yearly in some states and every two years in others; CE hours and required topics vary widely; and scope differs, with some states letting an RDH administer local anesthesia, place restorations, or practice under general rather than direct supervision once you hold the right permit. The American Dental Hygienists' Association keeps state-by-state licensure maps, but your own board is the source of truth for where you practice.

Verifying a dental hygienist license

You verify a dental hygienist license through the issuing state board's online license lookup, which holds the authoritative record of license status and any discipline on file. Employers run this check before your first day, so an expired or disciplined license shows up fast.

To confirm your own status, search your name or license number on your board's site; the record shows your license number, status, and expiration date. When you apply for a license in a new state, the board usually asks you to request verification of your existing license directly from the state that issued it, which documents your standing and any discipline for the new board.

Where dental hygienists work

A dental hygienist license is required for clinical hygiene jobs, and most dental hygienist roles ask for an active RDH plus a current radiography permit and BLS or CPR. Most positions sit in general and specialty dental practices, with others in community health centers, public health programs, hospitals, and dental education. Employers verify the license and check the expiration date before onboarding, and many list a specific state license because it doesn't transfer automatically.

If you support the dentist chairside rather than practice hygiene, that's a separate role with its own credential and a different scope of practice. The dental assistant (RDA) guide covers that path and how it differs from the RDH license.

Keeping the license active: moving, expanded permits, and lapses

Two situations come up often after you're licensed: moving states and adding scope. There is no national compact for dental hygiene, so moving means applying for a fresh license by credentials in the new state, which verifies your education, NBDHE result, clinical exam, and current license. Some states also make you sit their jurisprudence exam or, occasionally, an additional clinical exam before they license you.

Adding scope, such as a local anesthesia or restorative-functions permit, usually means extra coursework and a separate state authorization on top of the base license. If a license lapses, you reinstate it through the board that issued it, which typically means paying a reinstatement fee and clearing any back CE. Renewing on time costs less and takes less paperwork than reinstating a delinquent license.