Club rosters will be composed of a minimum of 22 active players and a maximum of 24 active players.
Each club must carry a minimum of eleven (11) rookies (combination of R1 and R2 players) with no professional experience other than specified below and may carry a maximum of thirteen (13) players with unlimited professional experience.
No player or player/coach may have attained twenty seven (27) years of age prior to January 1 of that playing season with the exception of one player who will be designated as a “Veteran” player who may have attained thirty (30) years of age prior to January 1 of that playing season provided that he meets the qualifications listed below.
For the 2017 season, players must have been born on or after January 1, 1990 to be eligible, aside from the Veteran classification player (one per team) who must have been born on or after January 1, 1987.
Players without prior affiliated baseball (MiLB) experience must be at least 18 years old to play in the Frontier League.
Rookie Classification: The Rookie classification will be split into two sub-classifications, Rookie 1 and Rookie 2. The Rookie 1 sub-classification will be for players who made their professional debut in the current season and therefore have no prior professional experience. The Rookie 2 sub-classification will be for players who held the Rookie 1 sub-classification in the previous year in the Frontier League or began their professional career during the 2014 season.
Minimum Appearance Exception: A player must have accrued a minimum of 50 at bats, 10 games pitched, or 20 innings pitched in a season for that season to count toward the classifications.
Experienced Classification: The Experienced classification is for all players who do not meet the requirements to be classified under the Rookie or Veteran classifications.
Veteran Classification: The Veteran classification is for a player who is over twenty seven (27) years of age but has not attained thirty (30) years of age prior to January 1 of that playing season. The player must have been listed on the Frontier League active roster or injured list for the team which he will be playing for all 96 games of the previous season.
21-year old exemption: Any player who is twenty-one (21) years of age or younger on or after January 1st of any season and is entering his first year in the Frontier League, regardless of any prior professional baseball experience, will be considered no higher than a Rookie-2 by Frontier League Rules. For the 2017 season, a birthdate of January 1, 1995 will be the cutoff to qualify under this provision.
Position change exemption: Starting with the 2016 season, position players who are switching to pitching and pitchers who are switching to playing a position will have their classifications reset to Rookie-2 provided that they do not appear in any games at their previous position (batting/running or pitching, depending on the switch).