How to Write ARDMS Credentials After Your Name: What the Abbreviations Mean and Why Order Matters

You've passed your registry exams, maintained your CME requirements, and earned the right to put those letters after your name. But how you actually write them matters more than most sonographers realize. Get the order wrong, omit the right punctuation, or conflate your specialty designations, and you signal to hiring managers, credentialing committees, and colleagues that you're unclear on your own qualifications. This guide breaks down exactly how the ARDMS credential display system works—and how to write it correctly every time.

The ARDMS Credential Architecture: Two Layers

The American Registry for Diagnostic Medical Sonography issues credentials at two distinct levels, and understanding this structure is the foundation of writing them correctly.

The Prerequisite Registration: RDMS, RDCS, RVT, or RMSKS

The first layer is your registered designation—the credential that confirms you have met ARDMS eligibility requirements and passed both the Sonography Principles and Instrumentation (SPI) exam (for most pathways) and at least one specialty examination. The four registered designations are:

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• RDMS — Registered Diagnostic Medical Sonographer
• RDCS — Registered Diagnostic Cardiac Sonographer
• RVT — Registered Vascular Technologist
• RMSKS — Registered Musculoskeletal Sonographer

Each of these is a standalone registration. You can hold more than one if you have passed the qualifying specialty exams for each.

The Specialty Designations: The Abbreviations in Parentheses

The second layer is the specialty abbreviation that follows each registered designation in parentheses. These tell readers specifically which organ system or clinical area you are credentialed in under that registration. For the RDMS, for example, specialty designations include:

• (AB) — Abdomen
• (OB/GYN) — Obstetrics and Gynecology
• (BR) — Breast
• (FE) — Fetal Echocardiography
• (NE) — Neurosonology
• (PS) — Pediatric Sonography
• (MS) — Musculoskeletal (note: if you pass the RMSKS exam, this is separate from the RDMS MS specialty)

For the RDCS, specialties include (AE) Adult Echocardiography, (PE) Pediatric Echocardiography, and (FE) Fetal Echocardiography. For the RVT, there is a single designation with no additional parenthetical specialty suffix.

The Correct Format: How to Write It Out

The standard ARDMS format places the registered designation first, immediately followed by the specialty abbreviations in parentheses, with no space between the registration and the parenthetical. Multiple specialties under the same registration are separated by commas inside the parentheses.

Single Registration, Multiple Specialties

If you hold the RDMS with Abdomen and OB/GYN specialties, write it as:

RDMS (AB, OB/GYN)

Not RDMS-AB/OB, not RDMS AB OB/GYN, not RDMS(AB)(OB/GYN). The parentheses group all specialties under that single registration.

Multiple Registrations

If you hold more than one registered designation, list each one as a separate unit, separated by commas or set on the same line with clear visual separation. A sonographer credentialed as both an RDMS and an RVT would write:

RDMS (AB, OB/GYN), RVT

If you also hold the RDCS with Adult Echocardiography:

RDMS (AB, OB/GYN), RDCS (AE), RVT

Why Order Matters Professionally

The sequence in which you list credentials is not arbitrary. There is a widely observed convention in healthcare that follows a logical hierarchy, and deviating from it can look careless to credentialing professionals who review hundreds of applications.

The General Rule: Highest Earned Degree First, Then Licensure, Then National Certifications

Healthcare credential display conventions generally follow this order after your name:

1. Highest earned academic degree (e.g., BS, MS, MHS)
2. State licensure (where applicable)
3. National certifications and registrations (ARDMS credentials)
4. Other professional designations

For most sonographers, this means a full credential string might look like:

Jane Smith, MS, RDMS (AB, OB/GYN), RVT

The degree comes first because it represents foundational education. National certifications follow because they demonstrate verified competency built on that educational foundation.

Within Your ARDMS Credentials: Primary Practice Area First

When listing multiple ARDMS registrations, place the one most central to your current clinical role first. If you work primarily in vascular but also hold the RDMS, lead with the RVT. This frames your identity for the reader immediately—before they even read your summary statement. On a resume or professional portfolio, that first credential sets the tone for everything that follows.

Within Specialties: Convention Over Preference

Inside the parentheses, many practitioners list specialties in order of acquisition, or in order of clinical relevance. Neither is technically wrong, but alphabetical order or order of relevance to the posted job is the cleaner professional choice. Avoid listing them randomly.

Where Your Credentials Appear—and How to Treat Each Context

Email Signature

Use the full formatted string: Jane Smith, RDMS (AB, OB/GYN), RVT. Don't abbreviate or drop specialties here. Your email signature is a professional document visible to referring physicians, administrators, and patients, and it should be accurate and complete.

Resume and CV

List credentials in the header directly after your name, then repeat them with full expansions in a dedicated Certifications or Credentials section. Spell out what each abbreviation means in that section—hiring managers outside sonography may not know that RDMS (OB/GYN) means you are credentialed in obstetric and gynecologic sonography. For ARDMS credentialing purposes when applying to new roles or facilities, clarity here directly affects how quickly your file is processed.

Name Badge and ID

Most facilities will include your primary registration on your badge. If you have flexibility, use the full ARDMS format. If space is limited, at minimum include your primary registration with specialties—dropping the specialties entirely can misrepresent your scope.

LinkedIn and Professional Profiles

LinkedIn's name field allows credential suffixes. Use the same formatted string you would on your resume. In the headline, you may choose to write out the full title—Registered Diagnostic Medical Sonographer—to improve searchability, since most non-sonographers will not search by acronym.

Common Mistakes to Avoid

Dropping the Parenthetical Specialties

Writing just "RDMS" without specifying specialties is incomplete. It tells the reader you are registered, but not in what. Two candidates who both hold the RDMS can have entirely different clinical competencies depending on their specialty designations. Include them every time.

Conflating ARDMS and CCI Credentials

The Cardiovascular Credentialing International (CCI) issues its own separate credentials—RCS, RVS, RCCS, and others—which are distinct from ARDMS registrations even where there is clinical overlap in echocardiography and vascular. Do not mix the formatting conventions or list them as though they are sub-specialties under an ARDMS designation. They are parallel, independent credentials and should be listed separately in your credential string.

Using Periods in the Abbreviations

ARDMS credentials are written without periods. It is RDMS, not R.D.M.S. Periods in professional abbreviations are largely obsolete in American healthcare credentialing and look outdated.

Listing Expired or Lapsed Credentials

This is a professional and potentially legal issue. If a credential has lapsed because CME requirements were not met or renewal was missed, remove it from your signature and resume immediately. Displaying a lapsed credential as active misrepresents your current credentialing status.

The Broader Professional Signal

How you display your credentials is, in a small but real way, a proxy for your professional self-awareness. Credentialing committees, department directors, and chief sonographers notice when someone has taken the time to understand and correctly format their qualifications. It demonstrates that you understand the system you operate within—which is exactly the kind of attention to detail that matters in diagnostic imaging, where precision is everything.

Your credential string is not decoration. It is a compressed professional history that tells a knowledgeable reader what you can do, how seriously you took your certification process, and how carefully you present yourself. Write it correctly, keep it current, and make sure it reflects where you actually practice.

Explore related topics: Registry Timelines · CCI Credentials · State Licensing · Specialty Certifications