The Rule 5 draft is a Major League Baseball (MLB) player draft that occurs each year in December, at the annual Winter Meeting of general managers. The Rule 5 draft aims to prevent teams from stockpiling too many young players on their minor league affiliate teams when other organizations would be willing to have them play in the major leagues. The Rule 5 draft is named for its place in The Official Professional Baseball Rules Book. The Rule 4 draft—more widely known as the "first-year player draft", "amateur draft", or simply the "MLB draft"—is a distinctly different process by which teams select high school and college players, and takes place annually in July.

The bonus rule was a rule instituted by Major League Baseball in 1947 to prevent teams from assigning certain players to farm teams. The rule stipulated that when a major league team signed a player to a contract with a signing bonus in excess of $4,000, the team was required to keep that player on their 25-man active roster for two full seasons. Any team that failed to comply with the rule lost the rights to that player's contract, and the player was then exposed to the waiver wire. Once a player remained with the team for two full seasons, he could be assigned to a farm team without repercussions.