If you're pursuing medical interpreter certification in the US, two certifying agencies dominate the field: the National Board of Certification for Medical Interpreters (NBCMI) and the Certification Commission for Healthcare Interpreters (CCHI). Both NBCMI and CCHI certify medical interpreters in the US, and both certifications are widely accepted by hospitals and agencies. But they are not interchangeable. While Interpreter Training Programs does not award either certificate, the Medical Interpreter Training program prepares students to pursue these credentials.

Here's the short version:

• Pick CCHI if your language pair is Spanish, Arabic, or Mandarin and you want simultaneous interpreting tested.
• Pick NBCMI if your target language is Cantonese, Korean, Russian, or Vietnamese and you want full certification including an oral exam.
• If your language has no oral exam at either body, written-only credentials like CoreCHI-P™ or the Hub CMI credential remain valuable for prospective employers.

The best choice depends on your language, your career goals, and your prerequisites. Let's break it down.

Overview of NBCMI and CCHI: who they are and what they certify

NBCMI and CCHI are the two national organizations that offer certification for healthcare interpreters in the United States. NBCMI operates under the International Medical Interpreters Association and functions as the national board for medical interpreting credentials. CCHI is the certification commission established in 2009 to create nationally recognized credentials for medical interpreters across all languages.

NBCMI offers two credentials for medical interpreters. The Hub CMI is a written exam open to interpreters of any language. The CMI (Certified Medical Interpreter) adds a language-specific oral exam and represents full certification. NBCMI offers the CMI credential for Spanish, Cantonese, Korean, Mandarin, Russian, and Vietnamese.

CCHI offers three types of certification credentials: CoreCHI™ (written-only, being sunsetted), CoreCHI-P™ (written plus performance), and CHI™ (full language-specific certification in Spanish, Arabic, and Mandarin). CCHI has offered certifications for all languages since 2009. CCHI's certifications are accredited by the NCCA, which is the same body that accredits many healthcare professions.

A key distinction: "full certification" means holding a credential that tests spoken interpreting performance in your language pairs-CMI at the National Board, CHI™ at CCHI. Written-only designations certify knowledge of ethics, medical vocabulary, and standards of practice, but do not assess live language proficiency. ITP provides the required medical interpreter training hours and NBCMI exam prep, though students targeting CCHI benefit from the same foundational skills. To understand the difference between a training certificate and certification, read ITP's explainer on certificates vs certification.

Which medical interpreter certification: which exam can certify your language pair?

For many aspiring certified interpreters, language coverage is the deciding factor in which medical interpreter certification to choose.

NBCMI is the only option for Cantonese, Russian, Vietnamese, or Korean interpreters seeking a national oral exam credential.

CCHI's CHI™ oral exams cover Spanish, Arabic, and Mandarin. CCHI also offers a written-only credential for any language through its CoreCHI certification-though this is being replaced by CoreCHI-P™, which adds a monolingual performance component. This means interpreters in less common language service pairings can still achieve certification, just without a bilingual oral exam.

Here's where it gets practical. A Korean–English interpreter in Boston would need NBCMI, since CCHI does not offer a CHI™ oral exam in Korean. An Arabic–English interpreter in California would lean toward CCHI, because NBCMI does not offer an Arabic oral exam. A Spanish–English interpreter has both options and can decide based on employer preference or whether they want simultaneous interpreting assessed.

Many hospital systems and language services agencies accept either credential as equivalent proof of competency, though regional preferences exist.

Exam structure and content: ethics vs terminology, modalities, and CoreCHI sunsetting

Both certifying bodies use a two-step process-a written exam followed by an oral exam where available-but the content emphasis differs significantly.

NBCMI's written exam emphasizes medical terminology in working languages, covering anatomy, clinical procedures, and specific medical scenarios. It runs 51 multiple-choice questions in 75 minutes, with roughly 61% of the weight on medical vocabulary and specialties.

CCHI's written exam emphasizes ethics and healthcare terminology, with more weight on intercultural communication, patient safety, and interpreting industry standards. The CoreCHI™ written credential was sunset after January 1, 2025; only CoreCHI-P™ and CHI™ will be awarded. For more detail on exam preparation steps, see ITP's guide on how to get a medical translator certification.

The oral exams differ in the interpreting modalities tested. CCHI's oral exam tests three interpreting modalities: consecutive interpreting (about 70%), simultaneous interpreting (about 17%), and sight translation (about 11%), plus a small written translation component. CCHI tests simultaneous interpretation; NBCMI does not. NBCMI's oral exam tests two interpreting modalities-consecutive interpretation and sight translation-across 12 scenarios plus two sight passages.

What does this mean in practice? Simultaneous interpreting requires rendering speech in near real-time alongside the speaker, common in emergency room briefings or large family conferences. Consecutive interpreting involves listening to a segment and then interpreting after a pause, which is the standard in most medical interpreting encounters. If your intended work environment demands simultaneous skills, CCHI's CHI™ formally validates that ability.

Eligibility, cost, and recertification

Both CCHI and NBCMI require at least 40 hours of medical interpretation training, plus a high school diploma and documented language proficiency. ITP's online medical interpreter training course meets this requirement, with the next live cohort starting September 9, 2026.

The organizations diverge on documentation. CCHI accepts informal language skills as proof of proficiency-such as real-world experience, self-attestation, or non-standardized documentation. NBCMI requires formal documentation for language proficiency, such as proficiency test scores, degrees, or transcripts. This can be a barrier for recent immigrants who are fluently bilingual but lack formal credentials.

Recertification timelines differ. CCHI recertification occurs every 4 years and requires 32 CEUs, including ethics and performance-based continuing education hours. NBCMI recertification occurs every 5 years and requires 30 CEUs. Both accept advanced medical interpreting classes, ethics workshops, and specialty programs as valid continuing education.

Certification can enhance job opportunities in healthcare settings-certified interpreters consistently report access to better-paying roles and more stable employment with hospital systems and agencies.

How Interpreter Training Programs helps you choose which medical interpreter certification to choose

Interpreter Training Programs (ITP) has provided live, Zoom-based interpreter training since 2011, serving both individual students and healthcare organizations. ITP is not a certifying body-it does not issue medical interpreter certification or accredited interpreter certifications. Instead, it provides 60 hours of medical interpreter training that helps students pass the national exams.

ITP's programs include live classes with native-speaking instructors, intensive practice in consecutive interpreting and sight translation, deep focus on medical terminology, and mock exams designed around NBCMI's written and oral exam formats. Students targeting CCHI also benefit-the core program builds the same foundation in ethics, standards of practice, and interpreting skills that both exams test.

The next cohort starts September 9, 2026. Whether you're pursuing NBCMI's CMI, CCHI's CHI™, or a written-only credential in a rarer language, formal training and a nationally recognized credential will meaningfully improve your standing with prospective employers in the interpreting industry. Compare both NBCMI and CCHI eligibility pages with your own background, then reach out to ITP's admissions team if you're unsure which path fits your education and language pair.