ATI writes and administers the TEAS, and it also sells prep for it — the SmartPrep tutorial, official-format practice tests, and a study manual, typically bought as a 90-day package. ATI's products give you the official format and full-length practice tests. Trelos is a complete daily study system for the content itself: it teaches every TEAS concept, drills it, and schedules review so it's still there on test day. It does not include full-length timed practice tests. Nothing about taking the TEAS requires buying the exam maker's prep.
Trelos is not affiliated with, endorsed by, or connected to ATI. “ATI” and “TEAS” are used only to identify the exam and the products being compared.
ATI (Assessment Technologies Institute) produces the TEAS itself, so its prep products come with something no one else can offer: the official question style, straight from the source. The SmartPrep Tutorial is a three-month online program covering the four TEAS areas — Reading, Math, Science, and English & Language Usage — that starts with a diagnostic and builds a study plan around your strengths and weaknesses. ATI's Practice Tests A and B mirror the real exam's 170 questions and 209-minute timing. The Comprehensive Package bundles SmartPrep, both practice tests, the printed Study Manual, a prep app, flashcards, and an A&P practice test for $199; a practice-test-only package runs about $80. Access is 90 continuous days. Details and current prices are on ATI's SmartPrep page and practice-test package page.
Trelos is a mobile-first retention engine for the TEAS. Every concept runs the same loop: you try questions first, then get a short lesson, then practice, then the concept returns on a schedule timed to just before you'd forget it. Confident mistakes come back first; practice is interleaved like the real exam. The TEAS track covers 180 questions across 30 concepts in six sections — Reading, Mathematics, Anatomy & Physiology, Biology/Chemistry/Scientific Reasoning, English Conventions & Grammar, and Vocabulary & Language Use — in standard multiple choice. Trelos covers the full TEAS content plan on its own; it does not include full-length timed practice tests. Every track's first topics are free with no sign-up to start.
| Trelos | ATI TEAS SmartPrep | |
|---|---|---|
| Relationship to the exam | Independent study tool | Made by the exam's author |
| Core model | Retention engine: guess → learn → drill → scheduled review | Diagnostic-driven tutorial + official-format practice tests |
| Full-length practice tests | No — short timed section tests and a 14-question mixed mock, not a 170-question sitting | Yes — Practice Tests A & B, 170 questions / 209 minutes |
| Spaced review | Automatic, built into every concept | Study plan from a diagnostic (per ATI's description) |
| Format | Mobile web app, short daily sessions | Online tutorial, practice tests, printed manual, app |
| Access | 12 months, one payment | 90 continuous days |
| Price | Free to start · $14 launch price ($29 after Nov 30) · pass guarantee | Comprehensive Package $199; practice-test package ~$80 |
| Best for | Making Science and Math content stick over weeks | Rehearsing the official format and timing |
Choose ATI's prep if you want the official format and official practice tests above all — especially the last two weeks before your date, when a full timed sitting is the most valuable thing you can do.
Choose Trelos if your problem is retention: anatomy and physiology you studied semesters ago, conversions that won't stay put, vocabulary that leaks between sessions. The engine's job is to make sure what you learn in week one is still producible in week six.
Official prep is a real advantage for format fidelity, and if you can afford $199 it isn't wasted money. But the TEAS is lost on retention far more than on format surprises — it's four subjects of old coursework tested in one sitting, and a diagnostic plus two practice tests doesn't by itself bring the material back. Trelos exists for that gap. Start with the free topics in the Trelos TEAS track; if the method works for you, the one-time price buys the full track for a year, with access extended free if you meet the guarantee's conditions and don't pass. If you also want a full-length timed rehearsal before your date, that's a separate purchase, from ATI or anyone else — Trelos doesn't sell one.
Pass guarantee: learn every concept in your track and keep up your scheduled reviews, and if you still don't pass, your access is extended free — three more months per attempt — until you do. It's an extension, not a refund.
If you’re preparing for the TEAS or the HESI A2 — many nursing programs accept either, and some require one specifically — Trelos has a dedicated track for each. Pick yours:
No credit card. Feel the retention engine work in your first session.
Related: TEAS Exam Guide · TEAS Study Plan · HESI vs TEAS · Free TEAS Practice Questions, or browse all Trelos exam guides.
How Trelos works · why guessing first, spaced review and mixed practice make it stick.
For organizations · group licenses for schools, programs, agencies and firms.