I've noticed that in addition to the 96 or so three-year EM programs, there are also 16 four-year programs (PGY1-PGY4). Is there any benefit to doing a four-year program as opposed to a three-year program? Are you just prolonging the agony of residency another year? There are 16 other programs that run PGY2-PGY4. Is this primarily for people who realize during their internship that they want to switch specialties? Or am I missing the big picture? You thoughts and opinions, please, ladies and gents. Thanks!