In the United States, four years of residency training after medical school are required, with the first year being an internship in surgery, internal medicine, pediatrics, or a general transition year. Optional fellowships in advanced topics may be pursued for several years after residency. Most currently practicing ophthalmologists train in medical residency programs accredited by the Accreditation Council for Graduate Medical Education or the American Osteopathic Association and are board-certified by the American Board of Ophthalmology or the American Osteopathic Board of Ophthalmology and Otolaryngology.