RTBD Passing Score 2026: Exactly What You Need to Pass

What "75" Actually Means on the ARRT Bone Densitometry Exam

If you are searching for the passing score on the Registered Technologist - Bone Densitometry credential, here is the short answer: you need a scaled score of 75. This is the postprimary Bone Densitometry (BD) examination administered by the American Registry of Radiologic Technologists (ARRT). It is not the ISCD CBDT certification and it is not a state-level Bone Densitometry Equipment Operator exam, and the scoring rules below apply only to the ARRT exam.

The number 75 trips up many candidates because it looks like a classroom grade. It is not. ARRT reports results on a 1-99 scaled-score system, and 75 is the point on that scale that represents the minimum acceptable level of knowledge for the credential. Understanding why that distinction matters will change how you judge your practice-test results and how you plan your preparation.

Why a Scaled Score Is Not a Percentage

ARRT's scoring process converts your raw performance into a scaled score so that candidates are judged against the same standard of knowledge regardless of which version of the exam they received. Different forms of an exam can vary slightly in difficulty. Scaling accounts for that, so a candidate who received a somewhat harder set of questions is not penalized relative to one who received an easier set.

For you as a candidate, this has three practical consequences:

• You cannot back-calculate a raw cutoff. Because the scaled score depends on the form you received, there is no single published "you must get X of 75 right" number. Do not trust any source that claims one.
• Practice-test percentages are only a rough proxy. A consistent high score on a well-built practice exam tells you that you are in good shape. A single score of 75% on a practice test does not map to a scaled 75.
• The standard is criterion-based. The cut point reflects the knowledge expected of a competent bone densitometry technologist, not a ranking against other test takers.

For ARRT's own explanation of how results are calculated and reported, review the scoring page at arrt.org's exam scoring resource.

The Exam Behind the Score: 105 Questions, 75 Scored

Your scaled score is built only from the scored questions. The exam is delivered by computer at Pearson VUE testing centers and includes:

Two details deserve attention. First, the 30 unscored pilot questions are indistinguishable from scored ones. You will not know which items count, so you must treat every question as if it does. Do not spend extra time agonizing over a strange-looking item and assume it is a pilot; that is a poor gamble.

Second, the 105 minutes of testing time is separate from the 125-minute appointment. The extra time covers the tutorial, check-in style steps, and similar non-testing activity. Your actual clock for answering questions is 105 minutes, which works out to a little under a minute and a half per question across the full set.

The format is primarily one-best-answer multiple choice, though other item formats permitted by the ARRT handbook may appear. Read each stem carefully: in a one-best-answer item, several options may be partly correct, and your task is to select the most appropriate response. The exam-length details are documented in the 2026 Postprimary Eligibility Pathway Handbook.

Where the Scored Questions Come From

ARRT publishes how many scored questions fall into each major examination category. For exams taken in 2026, the allocation is:

Those counts add up to the 75 scored questions. Procedures is by far the largest category, accounting for more scored items than Patient Care and Image Production combined. ARRT publishes counts rather than percentages, so treat the numbers above as the authoritative figures and avoid any site that restates them as official weightings.

For a closer look at the content inside each category, see our guide to the RTBD exam domains and all 3 content areas.

Reading the 2025 First-Time Pass Rate Correctly

ARRT's Annual Exam Report for 2025 recorded a first-time pass rate of 66.7% among 303 candidates for this examination. That figure is useful context, but it must be used carefully:

• It is an observed 2025 cohort result, not a prediction for 2026 test takers.
• It covers first-time candidates, so it does not describe repeat attempts.
• It reflects a group that includes radiographers, nuclear medicine technologists, and radiation therapists pursuing this postprimary credential, each with different levels of bone densitometry exposure.

A roughly two-in-three first-time pass rate tells you the exam is passable with preparation but not a formality. It also suggests that a meaningful share of candidates underestimate the exam. For the underlying numbers and how to interpret them, read our breakdown of the RTBD pass rate data, and for a candid assessment of difficulty see how hard the RTBD exam is. The source is the ARRT Annual Exam Report - 2025 (pages 3 and 26).

The 2026 vs. 2027 Content Specifications Boundary

This is the detail most likely to cost an unprepared candidate. The Bone Densitometry Examination Content Specifications that govern your exam were board approved in July 2021, took effect July 1, 2022, and apply through December 31, 2026. A replacement version takes effect January 1, 2027, and it changes both the question allocations and some topics.

Because the two blueprints differ in topics and not just counts, blending them can leave you studying material that will not be tested on your version, or missing material that will. Check scheduling windows in our RTBD exam dates guide so your test date and your study materials align.

Eligibility, Fees, and Attempts That Affect Your Score Strategy

The passing score is only relevant once you have cleared the prerequisites. A few mechanics directly shape how you should treat your first attempt.

Eligibility in brief

• A current supporting credential in Radiography, Nuclear Medicine Technology, or Radiation Therapy. Nuclear Medicine Technology may be held through NMTCB.
• ARRT ethics compliance.
• Structured education: 16 approved hours within the 24 months before you apply, with at least one credit in each of the three major categories.
• Clinical experience: 125 mandatory procedures within the qualifying 24-month window, made up of 25 daily quality-control activities, 50 lumbar-spine scans, and 50 femur scans. You must also complete at least three elective activity types at their specified repetitions, which is different from simply performing three extra scans. Actual scanning must be performed physically onsite.

The full picture is in our RTBD requirements guide, and the official pages are the ARRT Bone Densitometry credential page and the structured education and clinical experience documents it links to.

Fees and attempts

A limit of three attempts changes the math on rushing. Each retake also carries a reapplication fee, so a failed first attempt costs both money and time. For a full cost picture, see the RTBD certification cost breakdown.

Domain-by-Domain Score Protection

Because your result is one scaled score across all 75 scored questions, the goal is to avoid any single domain becoming a liability. Here is where candidates should concentrate.

A tidy way to think about it: Patient Care questions are the most reliable points to bank, Image Production questions reward understanding of principles, and Procedures questions reward hands-on familiarity. If you have logged your clinical procedures carefully, you already hold an advantage in the largest domain.

A Domain-Ordered Prep Sequence

Rather than a generic schedule, order your preparation by where the scored questions live. This timeline assumes you are already working through your structured education and clinical hours.

For a broader plan built around these domains, see the RTBD study guide, and keep the RTBD cheat sheet handy for last-week review. When you are ready to measure your readiness against realistic questions, try the RTBD practice tests.

After You Pass: Keeping the Credential Active

Earning a passing score is the start of a maintenance cycle, not the end. Annual ARRT registration renewal is $65 regardless of how many ARRT credentials you hold. Ordinarily, 24 approved continuing education credits are required each two-year biennium. Credentials earned on or after January 1, 2011 also require Continuing Qualifications Requirements (CQR) every ten years. The official references are ARRT's pages on continuing education and continuing qualifications requirements.

If you are weighing whether the investment pays off, our analyses of the credential's return on investment and the salary outlook cover that question without relying on invented figures.

Frequently Asked Questions