Major League Baseball transactions

Players on the 26-man roster are eligible to play in official major league games throughout the season.

The 40-man reserve list includes the players on the 26-man roster plus as many as 14 players who are either on the team's seven-, ten-, fifteen-, or 60-day injured list, who are on paternity leave for up to three days, or who are in the franchise's farm teams in Minor League Baseball.

From September 1 through the end of the regular season, each team is required to expand its active roster to 28 players.

Over the years, there have been several notable cases where a player acquired after the August 31 deadline made a significant contribution to a playoff-contending team but was ineligible for the postseason; for example, Pedro Ramos with the 1964 New York Yankees and Sparky Lyle with the 1980 Philadelphia Phillies.

Trades between two or more major-league teams may freely occur at any time during a window that opens two days after the starting date of the final game of the most recent World Series and closes at 4 pm Eastern Daylight Time (UTC 2000) on July 31.

[6] Beginning with the 2012 season, MLB allows one specific class of draft picks to be traded.

Those forfeited draft picks will eventually end up in the possession of small-revenue teams, which can then trade them if they wish.

Among the conditions of the trade were that if the Indians played no more games in 1994, "Indians general manager John Hart must write a check for $100 made out to the Minnesota Twins and take Twins general manager Andy MacPhail out to dinner.

Then, in 1959, an inter-league trading period was established, centered on the winter baseball meetings in December.

Later, there were two "inter-league" trading periods each year, one from after the World Series until mid-December and the second from a week before spring training began until March 15.

[14] A player has a finite number of option years in which he may be moved between the major and minor leagues up to five times per season as of 2022; previously, a player could be optioned an unlimited amount of times subject to the 15 day wait period for pitchers and two-way players and 10 day wait period for hitters except when either the "27th man" or injured list exception applied.

This gives the team time to decide what to do with the player while freeing up a roster spot for another transaction, if needed.

A player who is outrighted to the minors is removed from the 40-man reserve list but is still paid according to the terms of his guaranteed contract.

If the player withholds consent, the team must either release him or keep him on the major league roster.

This was instituted to allow players who may recover from their concussions quickly to be removed from the active roster and replaced for a shorter period of time than the standard IL term.

The bereavement list may be used when a player finds it necessary to leave the team to attend to a serious illness or death in his (or his spouse's) immediate family.

If chosen, the player must be kept on the selecting team's 26-man major league roster for the entire season after the draft—he may not be optioned or designated to the minors.

The selecting team may, at any time, waive the rule 5 draftee, such as when they no longer wish to keep him on their major league roster.

Once a rule 5 draftee spends an entire season on his new team's 26-man roster, his status reverts to normal and he may be optioned or designated for assignment.

This keeps teams from drafting players, then "hiding" them on the injured list for the majority of the season.

The Marlins chose Santana in the 1999 rule 5 draft, and traded him to the Minnesota Twins who kept him on their roster for the 2000 season, in which he toiled to a 6.49 earned run average at only 21 years of age.

Roberto Clemente is the only Rule 5 draft pick to be inducted into the Hall of Fame, having been selected by the Pittsburgh Pirates from the then Brooklyn Dodgers in 1955.