The National Adult Baseball Association (NABA) is an adult, amateur baseball organization, headquartered in Denver, Colorado. It offers competitive and recreational baseball for players in over 125 leagues in over 40 U.S. states. Over 25,000 player-members participate. The NABA is organized into groups categorized by age. The largest division of play is the Open Division (18 & Over), but there are also divisions for 25 Wood, 25 Aluminum, 35 Wood, 35 Aluminum, 45 Wood, 45 Aluminum, 50 Wood, 55 Wood, and 60 Wood. Where participation levels permit, leagues are divided into two or more competitive divisions. These divisions are then classified by experience level. The advanced level (AAA) is typically for players who have 3–4 years of college baseball and/or professional baseball experience. The intermediate level (AA) is generally for the players with high school baseball or some college experience. Finally, the recreational level (A) provides an opportunity for players whose love of the game perhaps exceeds their level of experience.

World championship series

Tournaments

Hall of fame

For a list of inductees, see footnote The NABA Hall of Fame was established in 1999.