How Many Exams Does It Take to Become a Registered Sonographer?

The “registry exam” sounds like a single big test you walk in, sit, and finish. For ARDMS, the largest credentialing body, it’s actually two. Here’s how the count works, and how it changes if you specialize in more than one area.

The two-exam answer

To earn one ARDMS credential, you pass two exams.

The first is SPI — Sonography Principles & Instrumentation. The second is a specialty exam. Both are required. Passing only one doesn’t give you a credential. So the base answer to “how many registry exams” is: two.

That’s the math for a single specialty. A sonographer who’s registered in general sonography (RDMS) passed SPI and the abdomen or OB/GYN specialty exam. A vascular sonographer (RVT) passed SPI and the Vascular Technology exam. Same two-part structure, different specialty exam.

What the SPI exam covers

SPI is the physics-and-instrumentation half. It’s about how ultrasound works rather than what you’re looking at on the screen. Sound waves, how the transducer turns echoes into an image, how the machine is set up and adjusted.

You take SPI once. It’s the shared foundation for the credentials that use it, so even if you later add a second specialty, you don’t repeat SPI.

There’s a separate requirement attached to SPI. Before you can sit for it, you need either a physics course (graded C+ or above) or 12 ultrasound-physics CME credits earned within the two years before you apply. That’s a prerequisite, not an exam — but it’s worth counting in your planning because you have to clear it first.

What the specialty exam covers

The specialty exam is the clinical half. This is where you prove you know the actual imaging work in your area — the anatomy, the protocols, the pathology you’d encounter on the job.

The specialty exam you take is tied to the credential you want. Cardiac, vascular, abdomen, OB/GYN, musculoskeletal — each has its own specialty exam. This is the half that “feels” like sonography, because it’s about the work you’ll do every day.

Adding more specialties: how the count grows

Here’s where the count can go up. ARDMS credentials are specialty-specific. If you want to be registered in two areas, you need to be credentialed in each.

But you don’t re-take SPI. SPI is the shared base. So for a second specialty, you add one more specialty exam — not another full pair.

• One specialty = SPI + 1 specialty exam = 2 exams
• Two specialties = SPI + 2 specialty exams = 3 exams
• Three specialties = SPI + 3 specialty exams = 4 exams

This is why some experienced sonographers hold several credentials. Each additional registration was one more specialty exam, built on the SPI exam they already passed.

The five-year rule that connects the two

Because a credential takes two exams, ARDMS sets a window between them. Once you pass your first exam — whether that’s SPI or the specialty — you have five years to pass the second.

Most candidates take both close together, often within the same year, so this rarely becomes a problem. But it’s the reason it’s not a great idea to pass SPI and then let years go by before tackling the specialty exam.

What about ARRT and CCI?

ARDMS is the most common path, but it’s not the only credentialing body. ARRT and CCI also certify sonographers, and they’re nationally recognized too.

Their exam structures aren’t identical to the ARDMS two-exam model. ARRT certifies sonographers through a Sonography (S) credential inside its broader Registered Technologist system. CCI issues registry-level credentials like RCS (cardiac) and RVS (vascular) by specialty. If you credential through ARRT or CCI rather than ARDMS, the exact number and arrangement of exams follows that body’s rules, not the SPI-plus-specialty count.

So the clean “two exams” answer is specifically the ARDMS answer. It’s the one most general sonography students plan around.