Specialists have undertaken an advanced post graduate training programme, usually over a minimum of three years, they have gained a post graduate qualification within their chosen field from a college overseen by the European Board of Veterinary Specialists or the American Veterinary Medical Association-American Board of Veterinary Specialists or been awarded a Diploma of the Royal College of Veterinary Surgeons. To maintain specialist status, Vet Specialists must undergo a re-accreditation process, overseen by one of the EBVS, AVMA-ABVS colleges or the RCVS every 5 years. Many specialists are re-accredited by more than one authority.