The CET (Certified EKG Technician) exam from the NHA has 100 scored questions (plus 20 unscored), a 390-of-500 scaled passing score, and a 2-hour limit. The fee recently ran about $117. At roughly a 70% pass rate it's the toughest of NHA's technician exams — the difficulty lives in rhythm interpretation. NHA also requires proof of 10 EKGs on live individuals before you certify.
The CET exam — the Certified EKG Technician certification from the National Healthcareer Association (NHA) — validates that you can set up and perform electrocardiograms, prepare patients for Holter and ambulatory monitoring, assist with cardiac stress tests, and recognize what a tracing is showing. It's a specialized, cardiology-adjacent credential. Where the CCMA is a broad clinical medical assistant certification and the CPT is focused on blood collection, the CET is focused on the heart's electrical activity — acquiring clean tracings and interpreting them.
Demand is steady and rising as the population ages and cardiovascular testing grows. According to NHA's 2025 industry data, 91% of employers require or encourage EKG certification. It's also a compact credential — there were 35,193 actively certified CET holders at the end of 2024, far fewer than the CCMA — which makes it a useful specialization to stack on top of another allied health certification.
| Scored questions | 100 (plus 20 unscored pretest) |
| Time limit | 2 hours (120 minutes) |
| Format | Multiple choice, computer-based |
| Passing score | 390 on a 200–500 scale (~78% of items) |
| Fee | ~$117 (confirm at nhanow.com) |
| 2024 pass rate | ~70% (69.66%, per NHA) — lowest of NHA's tech exams |
| Delivery | PSI test center, approved school, or live remote proctoring |
| Retake / validity | 30-day wait between attempts; certification valid 2 years |
As with all NHA exams, the passing standard is a scaled score of 390, not a fixed count of correct answers, and only your overall total decides pass or fail — there's no need to clear each domain separately. The 20 pretest questions are indistinguishable from scored ones, so treat every question as if it counts.
The NHA CET Detailed Test Plan splits the 100 scored questions across three domains, with published weights:
| Domain | Weight | Scored items |
|---|---|---|
| EKG Acquisition | 44% | 44 |
| Safety, Compliance & Coordinated Patient Care | 32% | 32 |
| EKG Analysis & Interpretation | 24% | 24 |
There's a strategic wrinkle here worth internalizing. EKG Acquisition is the biggest domain (44%) — chest-lead landmarks, correct electrode placement, and controlling artifact — and it's largely procedural, so it's the most learnable. But EKG Analysis & Interpretation is the smallest domain (24%) and the hardest — calculating heart rate from a tracing, assessing regularity, reading P-waves and QRS complexes, and identifying rhythms. Most candidates who fail fall short here. The winning plan is to lock down acquisition for volume, then invest disproportionately in interpretation relative to its weight, because that's where the exam separates passers from the rest.
You need a high school diploma or GED (or to be within 12 months of earning one), plus one of these pathways:
As with the phlebotomy credential, there's a hands-on requirement: you must document that you've performed at least 10 EKGs on live individuals. Watch for a common trap — many fully-online EKG programs don't include this live-patient component, so you may need to arrange the 10 EKGs separately before you're eligible to sit for the exam.
Of the NHA technician exams, the CET is the toughest: the 2024 national pass rate was about 70%, meaning roughly three in ten candidates don't pass — noticeably harder than the CPT (~76%) or CCMA (~81%). The reason is interpretation. Acquiring a clean tracing is a procedure you can learn by repetition, but reading one is pattern recognition: you have to identify a rhythm and measure a waveform precisely and quickly. Candidates who lean on clinical exposure without structured study tend to be strong on setup and weak on interpretation — and that 24% is exactly where the exam is decided.
Plan on roughly 30–60 hours over three to six weeks. Spend the bulk of it building automatic recall of lead placement and artifact troubleshooting (the largest domain), but deliberately over-invest in rhythm interpretation relative to its 24% weight, since that's the highest-failure area. Interpretation rewards repeated exposure to varied strips far more than it rewards re-reading definitions.
The CET failure pattern is a recall problem with a twist: interpretation isn't something you can recognize your way through. A candidate can read about sinus rhythm versus atrial fibrillation, feel they understand it, then freeze when a live strip demands a fast, confident call. Reading builds recognition; the exam demands rapid pattern recall across dozens of rhythms and precise waveform measurement. That gap is a solved problem in cognitive science. The techniques that close it are retrieval practice (forcing yourself to name the rhythm before checking), spaced repetition (revisiting each rhythm and lead-placement detail right as it starts to fade), and immediately re-teaching the strips you misread — especially the confident misreads.
Trelos is built entirely around those techniques. The EKG prep market is mostly static guides and flat question banks with no retention system — exactly the gap Trelos fills. It teaches each concept, drills it with exam-style questions and rhythm patterns, and schedules your reviews so both the procedural acquisition material and the harder interpretation material stay sharp through test day. It's a complete prep engine designed to take you to CET exam-ready on your phone, and you can feel the difference on the first session.
Start the CET on Trelos — freeNo credit card. Feel the retention engine work in your first session.Your official result and per-domain diagnostic post to your NHA account within about two business days, and once you pass you're a Certified EKG Technician — able to run EKGs, prep patients for Holter monitoring, and assist with stress tests. The credential is valid for two years; to keep it, you complete 10 continuing education credits and pay a renewal fee before it expires (with a one-year window to reinstate if it lapses). If you hold more than one NHA certification, you only need 10 CE credits total to renew them all — which is why the CET pairs so cleanly with a CPT or CCMA. Candidates building a broad patient-facing skill set often go on to the CPCT/A (patient care technician), which combines patient care, phlebotomy, and EKG — its guide is live now in the Trelos allied health series.