What Is A RTBS?

The Plain Answer: What an RTBS Is

An RTBS is a Registered Technologist - Breast Sonography: a sonographer who has earned the postprimary Breast Sonography credential from the American Registry of Radiologic Technologists (ARRT). It is a specialty credential built on top of a credential you already hold, not an entry-level path into imaging. Candidates demonstrate, through a proctored computer-based exam and documented clinical experience, that they can perform diagnostic breast ultrasound competently and safely.

On this site, "RTBS" is the shorthand we use for that specific credential. If you are brand new to the topic, our companion pieces on what RTBS certification is and what RTBS stands for cover the naming in more depth, while the RTBS certification overview gives the big-picture view.

Not to Be Confused With: ARDMS Breast and ARRT General Sonography

Breast ultrasound credentials sit in a crowded neighborhood, and candidates regularly mix them up. Three are worth separating clearly:

What a Breast Sonographer Actually Does

Breast sonographers perform diagnostic ultrasound of the breast and related structures, often working alongside mammography and radiologists. The RTBS exam reflects that workflow. You are expected to prepare the patient, optimize the ultrasound system, acquire and select representative images, and carry out breast-focused procedures, all while recognizing what a radiologist needs to see for final interpretation.

That last point is built into the credential's clinical requirements: every mandatory examination you log must be presented to the radiologist for final interpretation. The sonographer scans and documents; the physician interprets. Understanding that division of labor is part of professional readiness.

Who Can Earn It: Supporting Credentials and Clinical Experience

Because RTBS is postprimary, you cannot sit for it as your first ARRT credential. Eligibility has three layers. The full walkthrough lives in RTBS requirements: eligibility, prerequisites and how to qualify; here is the overview.

Layer 1: A Supporting Category

You need a current credential in one of these supporting categories:

• Radiography plus Mammography
• Sonography
• Vascular Sonography

The Sonography and Vascular Sonography supporting credentials may be held through either ARRT or ARDMS. The Vascular Sonography route is explicitly listed in the 2026 postprimary handbook's supporting-category table, so do not assume sonography candidates must come through general sonography alone.

Layer 2: Ethics and Structured Education

Candidates must meet ARRT ethics requirements and complete 16 structured-education hours within the 24 months before applying, with at least one credit in each major category.

Layer 3: Documented Clinical Experience

Within the qualifying 24-month window, you must independently perform 200 nonsimulated breast examinations and participate in at least 20 approved elective procedures. The counting rules are specific and easy to get wrong:

• Bilateral examinations count as two.
• No more than nine procedures may be logged per day.
• Scanning must be physically onsite.
• Each mandatory examination must be presented to the radiologist for final interpretation.

How the Exam Works: Format, Timing and Scoring

The exam is administered by Pearson VUE at a testing center. Key mechanics:

• Length: 225 total questions, made up of 185 scored questions and 40 unscored pilot questions. You cannot tell which are which, so treat every item as scored.
• Time: 225 minutes of testing time, which is distinct from the 245-minute appointment that includes check-in and administrative steps.
• Question types: Primarily one-best-answer multiple choice, with other permitted formats including multiple-response, sorting, and image or video items. Because this is a sonography exam, expect to interpret images and clips rather than just recall facts.
• Rules: Closed book. You may not bring a personal calculator, but test-center-supplied and on-screen calculators are available.

Many candidates search for a "three-hour" exam length; that claim does not apply to this credential. The official timing is the 225-minute figure above.

What "75" Really Means

The passing score is 75 on a 1-99 scaled-score system. It is not 75% of questions correct. Scaled scoring adjusts for the difficulty of the particular exam form, so the raw number of correct answers needed can differ between forms. The standard-setting report for Breast Sonography gives a form-specific raw-score equivalent and a projected pass rate rather than a universal raw cutoff. For a fuller explanation, see RTBS passing score: exactly what you need to pass.

The Three Exam Domains in Detail

The current Breast Sonography Examination Content Specifications (board approved July 2025, effective September 1, 2026) divide the scored questions into three major categories. Use the counts below rather than inferring percentages, and ignore any older allocations or invented five-domain breakdowns you may find elsewhere.

For a deeper breakdown of each category, read RTBS exam domains 2026: complete guide to all 3 content areas.

Fees, Attempts and Keeping the Credential Active

Upfront Costs

• Application and exam fee: $225 USD, or $450 if you apply using an ARDMS supporting credential
• Reapplication: $200

The price difference for ARDMS-supporting applicants is easy to miss, so check which credential you will list before budgeting. Our RTBS certification cost breakdown adds the surrounding expenses.

Attempt Limits

You are allowed three examination attempts within three years before you must requalify. That limit is not three attempts per year, which changes how you should think about a retake strategy.

Maintaining the Credential

• Annual ARRT registration renewal is $65, regardless of how many ARRT credentials you hold.
• Ordinarily, 24 approved CE credits are required per two-year biennium.
• Credentials earned on or after January 1, 2011 require Continuing Qualifications Requirements (CQR) every ten years.

Where RTBS Holders Work

Employers for breast sonographers tend to be settings where breast imaging is a service line. Typical examples include:

• Hospital imaging departments and breast centers
• Outpatient radiology practices
• Dedicated women's imaging or breast health clinics
• Screening and diagnostic programs paired with mammography

The credential is especially natural for technologists who already work in mammography or general sonography and want a formal, registry-backed breast ultrasound qualification. For openings and roles, see RTBS jobs. On earnings, we avoid quoting unverified figures here; the RTBS salary guide and the ROI analysis discuss compensation and value in context.

A Domain-Based Order of Attack

Rather than a generic schedule, sequence your preparation by how the blueprint is weighted and how the topics build on each other. A full plan is in the RTBS study guide; this is the RTBS-specific logic.

When you are ready to test yourself under realistic conditions, our RTBS practice tests mirror the multi-format, image-heavy style of the real exam. Check RTBS exam dates for scheduling, and confirm current details on the ARRT site before you apply.

Frequently Asked Questions

In short, an RTBS is a registry-verified breast sonography specialist whose credential rests on supporting qualifications, documented hands-on experience and a rigorous exam centered on image production. If that matches your career direction, your next step is confirming your supporting category and starting your clinical log.