CDI Certification

What CDI Certification Actually Is

CDI certification is the credential that identifies a Deaf professional as qualified to work as a Certified Deaf Interpreter - someone who partners with hearing interpreters, or works independently, to interpret between ASL, other visual-gestural communication, and international sign, often for Deaf consumers who use non-standard, minimal, or idiosyncratic language. It is not a beginner credential and it is not the same thing as general ASL interpreter certification. If you're still asking basic questions like what the letters mean or what the role involves, start with our companion pieces on What Is CDI?, CDI Meaning, or What Does CDI Stand For? before diving into the mechanics below.

This article focuses specifically on how the certification process works today - who administers it, what the exam looks like, what it costs, and how the pieces fit together. For a deep dive into passing strategy, see our CDI Study Guide 2026.

Who Owns What: RID, CASLI, and Meazure Learning

One of the most confusing parts of CDI certification is that three organizations are involved, each with a distinct role:

• RID (Registry of Interpreters for the Deaf) - owns the certification itself and sets eligibility requirements (education, audiogram, application review).
• CASLI (Center for the Assessment of Sign Language Interpretation) - develops and administers all testing content, including the knowledge exam and the performance exam.
• Meazure Learning (formerly Scantron) - the testing vendor that physically delivers the CASLI Generalist Knowledge Exam at contracted testing sites.

The performance exam works differently: it's scheduled directly with a Local Test Administrator rather than through Meazure Learning. Understanding this three-way split matters practically - if you have a question about eligibility, that's RID; if you have a question about exam content or scoring, that's CASLI; if you have a scheduling or test-day logistics question for the knowledge exam, that's Meazure Learning.

Eligibility Requirements and the Deaf-Interpreter Rate

As of May 17, 2021, RID's education requirement is a bachelor's degree in any field, or completion of RID's Alternative Pathway. Notably, RID removed the 40-hour training requirement in June 2021 specifically to create equity between Deaf and hearing interpreter candidates - a meaningful policy shift if you were tracking older eligibility lists.

To qualify for Deaf-interpreter pricing and eligibility, you must submit an audiogram documenting hearing loss of 65db or more in one or both ears. A few practical notes:

• The audiogram does not need to be recent.
• It must name the applicant and the audiologist or office that produced it.
• Without this documentation, you won't be routed into Deaf-interpreter rates or eligibility pathways.

For the full breakdown of every prerequisite, including how the Alternative Pathway works in detail, see CDI Requirements 2026: Eligibility, Prerequisites & How to Qualify.

Exam Structure: Knowledge Exam and Performance Exam

The legacy CDI-Knowledge Exam retired on January 1, 2021. It was replaced by the CASLI Generalist Knowledge Exam (CGKE), a computer-based test with two distinct parts:

• Fundamentals of Interpreting - 120 multiple-choice questions. Exactly 60 are presented in written English with English answer choices, and 60 are presented in ASL with ASL answer choices. Candidates are not permitted to choose a language preference; the split is fixed.
• Ethical Decision Making and Cultural Responsiveness Exam - 8 multi-step case studies that require applying judgment to realistic scenarios rather than recalling isolated facts.

You must pass Fundamentals of Interpreting before you become eligible to sit the performance exam. If you fail only one of the two knowledge exam parts, you only need to retake that specific part - you don't have to redo both.

Once you clear the knowledge exam, the next step is the CASLI Generalist Performance Exam for CDI, scheduled directly with a Local Test Administrator rather than through Meazure Learning. This exam evaluates live interpreting performance, not multiple-choice recall, and it is graded on a much longer timeline than the knowledge exam.

For a full comparison of expected passing scores across both parts, read CDI Passing Score 2026: Exactly What You Need to Pass. And if you're wondering how the difficulty compares to other interpreting credentials, see How Hard Is the CDI Exam? Complete Difficulty Guide 2026.

The Four CDI Exam Domains

CASLI's content is organized around four domains that trace the arc of a Deaf interpreter's involvement in an assignment, from before you ever meet the consumer to after the job ends. Knowing these domains cold - not just their names, but what decisions live inside each one - is the single most CDI-specific thing you can do to prepare.

Both exam components draw on all four domains, but the case-study format of the Ethical Decision Making and Cultural Responsiveness exam leans especially hard on Domains 1, 2, and 4, since those scenarios often ask you to judge appropriate action before or after an encounter rather than during it. For a domain-by-domain study breakdown, see CDI Exam Domains 2026: Complete Guide to All 4 Content Areas.

Fees, Timelines, and Retake Rules

CDI-rate exam fees effective January 1, 2023 break down as follows:

• CASLI Generalist Knowledge Exam (CGKE): $280 regular / $225 RID member
• CASLI Generalist Performance Exam for CDI: $395 regular / $310 RID member
• Single Fundamentals or Case Studies (Gap Test) retake alone: $140

Timing rules matter as much as the dollar amounts. Exams must be taken within one year of purchase, or before the testing cycle expiration - whichever comes first. The full testing cycle runs five years from your first PASS notification, so your effective clock starts the moment you pass, not when you first registered. If you fail a knowledge exam, RID requires a three-month waiting period before you can retake it, so plan your calendar accordingly rather than assuming you can re-sit immediately.

For the complete cost picture, including how member status and retake scenarios change the math, see CDI Certification Cost 2026: Complete Pricing Breakdown. And to map out exact registration windows and deadlines, check CDI Exam Dates 2026: Testing Windows, Deadlines & Scheduling.

The Bridge Plan for Legacy CDI-Knowledge Exam Holders

If you passed the retired CDI-Knowledge Exam before it was phased out on January 1, 2021, you cannot simply carry that pass-status forward unmodified. RID requires a bridge plan consisting of an unscored learning module plus the Case Studies gap test.

The reason is structural, not punitive: the old CDI-Knowledge Exam was derived from RID's 2000 Role Delineation Study, while the current CASLI Generalist Performance Exam for Deaf Interpreters - released November 16, 2020 - is derived from CASLI's 2018 Deaf Interpreter Job Task Analysis. The job itself has been re-studied and re-defined in the intervening years, so the bridge plan exists to align legacy-certified professionals with the updated task analysis before they're eligible to move forward under current standards.

If this applies to you, budget time for the learning module in addition to exam prep - it's not optional and it's not a formality you can skip by simply re-registering for the performance exam.

How to Sequence Your Prep Around the Two-Part Exam

Because Fundamentals of Interpreting is a hard gate to the performance exam, and because it's also the part most likely to trip up strong practitioners who haven't reviewed interpreting theory in written or ASL-question form, it deserves the earliest and heaviest block of dedicated study time. Ethical Decision Making and Cultural Responsiveness benefits from a slightly different rhythm - since it's case-study based, it rewards discussion and scenario-walkthroughs more than flashcard-style review.

This sequencing is CDI-specific, not a generic study calendar: it's built around the fact that Fundamentals gates your eligibility for everything downstream, and that the case-study exam draws disproportionately on the "bookend" domains rather than the live-encounter domain. For a more exhaustive prep framework, see the CDI Study Guide 2026: How to Pass on Your First Attempt, and for quick-reference review once you're close to test day, the CDI Cheat Sheet 2026 is built for exactly that purpose.

Life After Certification: Who Hires CDIs

CDI certification opens work in settings where a Deaf consumer's language use, cultural background, or communication needs require a Deaf professional working alongside - or instead of - a hearing interpreter. This includes legal and courtroom settings, medical and mental health encounters, educational settings involving Deaf students with atypical language exposure, and international or platform-based assignments involving international sign. Because the credential is relatively specialized, demand tends to concentrate in agencies and institutions that already work regularly with Deaf communities.

If you're evaluating whether the time and cost investment described above is worth it for your career goals, our Is the CDI Certification Worth It? Complete ROI Analysis and CDI Salary Guide 2026 articles go deeper into that decision. For a look at where the actual job postings are, see CDI Jobs, and for structured skill-building beyond exam prep, CDI Training covers ongoing professional development options.

You can also run full-length practice sessions modeled on the CGKE format at CDI Exam Prep's practice test platform before you commit to an official registration date - it's a low-cost way to see where Domains 1 through 4 actually show up in question form.

Frequently Asked Questions