RTT Certification

What This Credential Actually Is

On this site, RTT stands for Registered Technologist - Radiation Therapy. It is a credential issued by the American Registry of Radiologic Technologists (ARRT) in the official discipline called Radiation Therapy (T). "RTT" is the abbreviation used here, not ARRT's own discipline designation, so you will see ARRT's materials refer to the Radiation Therapy examination rather than an "RTT exam." If you want the plain-language basics first, see What Is RTT Certification? and What Does RTT Stand For?.

Radiation therapists are the clinicians who deliver prescribed radiation treatments to patients with cancer and other conditions, operate treatment and simulation equipment, verify setups, and monitor patients through a course of treatment. The ARRT credential is the primary route into that role for graduates of radiation therapy programs. It is earned through the primary pathway, meaning you qualify by completing an educational program and passing the examination. It is not a postprimary examination layered on top of a Radiography credential.

Who Qualifies: Degree, Program, and Ethics

Eligibility under the primary pathway has three pillars. A fuller walkthrough lives in RTT Requirements 2026: Eligibility, Prerequisites & How to Qualify; here is the working summary.

• Education: an associate degree or higher from an ARRT-recognized accredited institution. The degree may be in any major, but it must be conferred before you sit for the examination.
• Program: completion of an ARRT-verified radiation therapy educational program, including its didactic coursework and clinical competencies.
• Ethics: compliance with ARRT's ethics requirements, which are reviewed as part of the application.

Two points trip people up. First, an existing Radiography credential is not a universal prerequisite, so you do not need to be a registered radiographer to pursue this path. Second, there are two separate clocks. The degree must be earned and the application submitted no more than three years after you complete your program. That initial application deadline is distinct from the three-year window for examination attempts described later.

The Clinical Competency Load

Radiation therapy programs are unusually hands-on, and ARRT specifies the competencies a candidate must document. Your program director or designee must verify clinical competency through in-person direct observation. Remote or virtual observation is not accepted, which is worth knowing if you are evaluating program formats.

Notice how closely this list mirrors the exam. Dose calculations, simulation, accessory devices, and treatment delivery all reappear as testable content. Your clinical logbook is, in effect, a preview of the Procedures domain.

Exam Format and Test-Day Mechanics

The examination is delivered at Pearson VUE test centers and is computer-based. It is closed book. Here is how the structure breaks down:

• 230 total questions: 200 are scored and 30 are unscored pilot questions. You cannot tell which are which, so treat every item as if it counts.
• Time: 230 minutes of examination answering time, inside a 250-minute appointment that also covers the tutorial, nondisclosure agreement, and survey.
• Item types: primarily single-best-answer multiple choice, with possible alternative formats and image-based questions. ARRT's handbook also describes multiple-response and ordered-response formats, so be ready for items where you select more than one answer or arrange steps in sequence.
• Navigation: you must answer each item before advancing, but you can flag questions and return to them.
• Calculators: basic and scientific on-screen calculators are available, and Pearson can supply a basic four-function calculator on request. Personal calculators are prohibited.

The "must answer before advancing" rule changes pacing strategy. You cannot skip a hard item and leave it blank; instead, commit to your best answer, flag it, and return if time allows. For a deeper look at how demanding the test feels, read How Hard Is the RTT Exam? Complete Difficulty Guide 2026.

The Three Content Domains

ARRT organizes the examination into three major content categories. These are official exam content categories, not course headings, so your program's syllabus may slice the material differently. The allocations below are scored-question counts out of 200, taken from the content specifications that control examinations through January 31, 2027. For the full breakdown, see RTT Exam Domains 2026: Complete Guide to All 3 Content Areas.

Scope boundaries worth knowing

The specifications draw several lines that help you avoid over-studying:

• Units: SI units are primary.
• Brachytherapy: coverage is limited to basic common-use concepts, surrounding-tissue dose, and radiation protection. You will not be tested on detailed procedures or isotope characteristics.
• Staging: limited to basic concepts rather than site-specific staging systems.
• Billing: specific CPT codes are excluded.

Scoring, Attempts, and the 2025 Cut-Score Change

The passing score is 75 on ARRT's 1-99 scaled-score range. That is not 75% of questions correct. ARRT converts raw performance into a scaled score so that results remain comparable across different exam forms. Our dedicated explainer, RTT Passing Score 2026: Exactly What You Need to Pass, covers this in detail.

A revised examination cut-score standard took effect February 1, 2025. The reported passing score remains 75 scaled, but the underlying standard was updated, so older anecdotes about how hard the exam "felt" may not map neatly onto today's version.

You have three examination attempts within three years of the opening of your initial examination window. Plan your first attempt as though it is the one that counts, because the window is finite.

That 77.1% figure comes from 958 first-time candidates in 2025. It is a useful anchor, though one year of data should not be over-read. For context on trends and interpretation, see RTT Pass Rate 2026: What the Data Shows.

Fees and Registration Mechanics

The initial application fee is $225 USD, and an examination reapplication costs $200 USD. Both are paid to ARRT, with testing delivered through Pearson VUE. Budgeting beyond these two numbers, including program costs and annual renewal, is covered in RTT Certification Cost 2026: Complete Pricing Breakdown. For scheduling specifics and deadlines, see RTT Exam Dates 2026: Testing Windows, Deadlines & Scheduling.

Because a retake requires a fresh $200 reapplication, the economics favor thorough preparation before your first sitting rather than testing early and hoping for the best.

Sequencing Your Review by Domain

You do not need a generic study system here; you need an order that matches how the domains reinforce each other. Our full plan is in the RTT Study Guide 2026: How to Pass on Your First Attempt, but this timeline shows the logic of sequencing by content area.

The rationale: physics and protection give you the vocabulary for dose and delivery, so Safety comes first even though Procedures is bigger. Patient Care last works well because much of it is judgment and communication content that your clinical rotations have already drilled. Adjust the order to your own weak spots, and use a one-page review sheet for final-week consolidation.

Keeping the Credential Active

Earning the credential is the beginning. To stay certified and registered, you need to do four things:

1. Renew annually. The fee is $65 regardless of how many ARRT credentials you hold.
2. Comply with ethics requirements on a continuing basis.
3. Earn 24 approved CE credits per two-year biennium. This is per biennium, not per credential, so holding multiple credentials does not multiply the burden.
4. Complete Continuing Qualifications Requirements (CQR) every 10 years if your credential was earned on or after January 1, 2011. CQR involves a professional profile, a structured self-assessment, and any prescribed CE. ARRT also permits accepting the maximum CQR CE prescription instead of taking the self-assessment.

Where Certified Therapists Work

Radiation therapists are employed wherever radiation treatment is delivered. That typically means hospital-based radiation oncology departments, freestanding cancer centers, and outpatient oncology practices. Treatment teams usually include radiation oncologists, medical physicists, dosimetrists, nurses, and therapists, and your role sits at the point where the plan becomes a delivered treatment. Browse openings and role types in RTT Jobs, and compare compensation in the RTT Salary Guide 2026: Complete Earnings Analysis. If you are weighing the investment, Is the RTT Certification Worth It? Complete ROI Analysis 2026 lays out the tradeoffs.

For candidates still mapping the road from classroom to registry, RTT Training explains how educational programs fit into the path described above.

Frequently Asked Questions

When you are ready to test your recall under realistic conditions, work through the full-length items on our RTT Exam Prep practice test site and use our RTT Certification overview as a quick reference for the essentials.