How to Become a Certified Nursing Assistant (CNA) in the US

Certified Nursing Assistants (CNAs) provide the hands-on, day-to-day care that keeps hospitals, nursing homes and home care agencies running — helping patients and residents with bathing, dressing, eating, mobility and basic health monitoring, and reporting changes back to nurses. It's one of the fastest routes into US healthcare: most people go from application to certified, paid work in a matter of weeks rather than years. The catch is that CNA rules are set state by state, so the exact hours, exam format and registry process you'll meet depend on where you live. This guide covers what's consistent everywhere and flags where you'll need to check your own state's rules.

Entry requirements

To enrol in a CNA training program you'll typically need to be at least 16–18 (the minimum varies by state and program), pass a background check, and in some states provide proof of required immunisations or a negative TB test before starting clinical placements. Some programs ask for a high school diploma or GED; many don't. There's no prior healthcare experience expected — CNA programs are built for people starting from scratch.

State-approved training: how many hours?

Every state's CNA program has to meet a federal floor set by the Centers for Medicare & Medicaid Services (CMS): under 42 CFR §483.152, a nurse aide training and competency evaluation program must include no less than 75 clock hours of training, at least 16 of which are supervised practical (clinical) training.

That 75-hour figure is a minimum, not a norm — most states require more. According to PHI National's tracking of state requirements, roughly 30 states and Washington DC now require more than 75 hours, up to 180 hours in some cases, and 13 states plus DC have adopted the 120-hour standard recommended by the National Academy of Medicine. California, for example, requires 150 hours (100 of them clinical); Missouri requires 175 hours (100 clinical); Maine requires 180 hours (70 clinical). Around 20 states, meanwhile, still sit at the 75-hour federal floor. In practice, programs run anywhere from about four to sixteen weeks depending on the state, the number of hours required, and whether you study full-time or part-time.

Because this varies so much, always check your own state nursing board or state nurse aide registry for the exact hour requirement before enrolling in a program — don't assume your state matches a neighbouring one.

The competency exam

Once you complete an approved training program, you sit a two-part competency evaluation, usually within a set window (often around two years) of finishing training:

• A written (or oral) knowledge exam — typically multiple choice, covering the topics taught in your program: infection control, communication, resident rights, safety, and basic care skills.
• A skills (clinical) evaluation — a hands-on, observed demonstration of a set of care tasks, such as handwashing, transferring a resident, or taking vital signs, assessed by a trained evaluator against a standard checklist.

Many states use the National Nurse Aide Assessment Program (NNAAP) exam or an equivalent state-specific exam; the exact format and pass marks are set by each state's testing vendor, so check with your program or state registry for the specifics.

State registry listing

Passing both parts of the exam gets your name added to your state's Nurse Aide Registry — the official record employers check before hiring. This is the step that actually makes you a "Certified" Nursing Assistant. Importantly, this certification is state-specific: it doesn't automatically transfer if you move, though many states offer reciprocity or a streamlined transfer process if your original state's requirements were equivalent — again, this varies, so check with the state you're moving to.

Most states require renewal roughly every two years. If you've worked a minimum number of paid hours during that period, renewal is usually just a form and a fee; if you've had a gap in employment, you may need to retake all or part of the competency exam.

Typical timeline

Put together, a realistic timeline looks like: four to sixteen weeks of state-approved training (state-dependent), followed by scheduling and sitting the two-part exam — often within a few weeks of finishing the course — then registry listing, usually a matter of days once results are confirmed. Many people go from a standing start to certified, paid work within two to four months.

Career progression

CNA is a common entry point into US healthcare careers more broadly. With experience, CNAs often move into specialised roles (such as restorative care or hospice), Patient Care Technician positions, or use the role as a stepping stone toward becoming a Licensed Practical Nurse (LPN) or Registered Nurse (RN) — many LPN and RN programs value hands-on CNA experience, and some employers offer tuition support for CNAs who want to continue their education while working.

Frequently asked questions

How long does it take to become a CNA?

Most people complete training and certification in two to four months, though this depends heavily on your state's required training hours and how quickly you can schedule the competency exam.

Do CNA requirements really vary that much by state?

Yes. Training hours alone range from the federal minimum of 75 hours up to 180 hours depending on the state, and exam formats, registry processes and renewal rules also differ. Always confirm the specifics with your own state's nurse aide registry or health department before enrolling.

Can I transfer my CNA certification to another state?

Sometimes, through a reciprocity process, but it isn't automatic. Contact the nurse aide registry in the state you're moving to before you relocate to understand what's required.

Is a CNA the same as a Home Health Aide?

They're closely related but not identical — a Home Health Aide (HHA) role generally has similar or overlapping training requirements but is regulated separately in most states, and often focuses on care delivered in a person's home rather than a facility.

Because CNA rules genuinely differ from state to state, the single most useful thing you can do before enrolling is check your own state nurse aide registry directly rather than relying on a national average. From there, the path is short and practical compared with most healthcare careers. If you're weighing up care roles more broadly, our guide to becoming a Healthcare Assistant in Ireland shows how a similar role is structured outside the US, and our complete guide to healthcare compliance and CPD training in the US covers what comes next once you're working, including HIPAA training requirements that apply across most US healthcare employers.