American College of Veterinary Internal Medicine (ACVIM): How to Become Board-Certified

An internal medicine veterinarian — a veterinary internal medicine specialist — is a veterinarian ACVIM has certified in one of the six specialties AVMA lists under the college: Cardiology, Small animal internal medicine, Large animal internal medicine, Neurology, Oncology and Nutrition.

AVMA counts 4,537 active ACVIM diplomates across the college as of December 31, 2025 — 1,957 in small animal internal medicine, 886 in large animal internal medicine, 656 in oncology, 557 in neurology, 497 in cardiology and 104 in nutrition.

The per-specialty figures do not reconcile to the college total, so read the split exactly as AVMA prints it rather than as a complete breakdown.

Certification is by specialty, and the requirements below apply across all six, with each specialty's own additions covered at the end.

For a closer read, separate guides on this site cover veterinary oncology, veterinary cardiology, veterinary neurology and veterinary nutrition in more depth.

ACVIM's common requirements start with a Doctor of Veterinary Medicine or its equivalent and legal eligibility to practice veterinary medicine in the US, Canada, or another country.

Before the residency comes a one-year rotating internship in veterinary medicine and surgery, or equivalent broad-based veterinary experience — which the college describes as typically three years in general clinical practice.

The residency itself is an ACVIM-approved residency training program, and most are a minimum of three years of continuous training.

Large animal internal medicine, neurology and nutrition currently allow approval of programs that can be completed in two years of continuous training.

For planning, the timeline depends on the specialty you choose as well as the route you took before it: the same college, program lengths that differ by specialty.

A non-traditional residency training program is intentionally non-continuous: instead of one unbroken run, the training takes place within clearly defined, continuous blocks of training time.

The rules around it are firm — all specialties stipulate that in a non-traditional program all of the specialty's requirements for residency training must be met, and individual ACVIM specialties may stipulate additional expectations for non-traditional programs.

A non-traditional program is a maximum of five years in duration.

That is the route for a veterinarian whose circumstances cannot absorb a continuous residency: the specialty's residency requirements still all apply, and its own additional expectations may too, but the calendar can stretch, inside a five-year ceiling and the blocks the college defines.

Two examinations sit on the path.

The General Examination can be taken for the first time once a candidate has completed at least 72 weeks of an approved residency training program before the examination date — so a first sitting can fall while the residency is still underway.

The Specialty Examination is gated by credentials: for all specialties, credentials are a prerequisite for the Specialty Examination, all components are due by the date specified on the ACVIM website, and the deadline falls in the year preceding the examination.

Certification then has to be kept: every diplomate who completed credentials and became a diplomate on or after January 1, 2016 holds a certificate valid for 10 years under the Maintenance of Credentials (MOC) program, and ACVIM states that a diplomate who falls out of compliance with certification requirements may not use the ACVIM or DACVIM credential in association with their title, work, or institution.

ACVIM's manual covers the certification and residency-training requirements common to its specialties, and each specialty may set additional or different requirements of its own that the manual does not detail.

The differences already visible in the common rules point the same way: large animal internal medicine, neurology and nutrition currently allow programs completed in two years of continuous training, while most programs run a minimum of three years.

Treat the common path as the starting point and check the specialty's own requirements with ACVIM before committing to a plan.