Unconditional Release Waivers

Unconditional Release Waivers are irrevocable and cannot be withdrawn once they are requested.

While a player claimed off Outright Assignment Waivers costs $50,000 (formerly $20,000), a club can claim a player off Unconditional Release Waivers for the minuscule sum of $1. However, a club that claims a player off Release Waivers is responsible for paying 100% of the player's remaining salary, whereas if the same club waits until the player clears Release Waivers, the club can sign the player for the MLB minimum salary (or prorated portion of the MLB minimum salary), with the player's former club responsible for the balance.

A player who is claimed off Unconditional Release Waivers has the option to decline the assignment and become a free-agent (he has up to five days to decide). For most players, refusing an Unconditional Release waiver claim means the player's contract is terminated with no severance and his former club owes him nothing (same as an Article XX-D minor league FA who refuses an Outright Assignment), but for a player with "no trade" rights who refuses an Outright Release waiver claim, the player is owed his full salary for the balance of the contract, same as if he had not been claimed.

A player on an MLB Reserve List (40-man roster) who is released during the period of time extending from MLB Opening Day through August 31st cannot be added back to the MLB Active List of the club that released the player for at least 30 days - UNLESS - the MLB Active List of the club that released the player has at least one open slot during the period of time beginning when the player is released and extending up until the released player is re-signed and added back to the club's MLB Reserve List, and a player on an MLB 40-man roster who is released anytime during the period of time extending from September 1st to MLB Opening Day cannot be added back to the MLB 40-man roster (or MLB Active List) of the club that released the player until May 15th. 
NOTE:: While an unsigned player under club control who is not tendered a contract for the next season ("non-tendered") becomes a free-agent, it is not considered the same thing as an Unconditional Release, so a club can re-sign a non-tendered player to a Major League contract (or minor league contract) without any restrictions anytime after the player is non-tendered. Thus, the MLB contract tender date is a sort of roster "island oasis" in the middle of the off-season where a club can drop a player from its MLB Reserve List (including injured players) without having to worry about waivers or restrictions on off-season outright assignments or Outright Release.

A player on an MLB Reserve List (40-man roster) signed to a non-guaranteed contract who is released more than 15 days prior to Opening Day receives 30 days salary as termination pay (paid at the "minor league rate" if the player is signed to a "split contract"), and a player on an MLB Reserve List signed to a non-guaranteed contract who is released 15 or fewer days prior to Opening Day receives 45 days salary as termination pay (all players paid at the "Major League rate"). A player on an MLB Reserve List signed to a non-guaranteed contract who is released prior to MLB Opening Day receives 100% of his salary as termination pay if he is released while he is unable to render service due to an injury or illness suffered while under contract to the club.     
NOTE: Beginning in 2022, a player eligible for salary arbitration who signs a contract prior to an arbitration hearing will receive 100% of his salary if he is released prior to MLB Opening Day (although salary liability for former club would be partially offset by the pro-rated MLB minimum salary if the player signs an MLB contract with another club after being released).  

A player on an MLB Reserve List who is released during the MLB regular season receives 100% of his salary as termination pay (paid at the "minor league rate" for players on Optional Assignment to the minors).

An unsigned player on an MLB Reserve List released during the off-season receives no termination pay.

An MLB Rule 5 Selected Player (a player who was selected in the MLB Rule 5 Draft) cannot be released until restrictions have been removed, and if Rule 5 restrictions have been removed and the player is released, the player's termination pay is always paid at the "Major League rate" as long as he is released prior to being outrighted to the minors.

Unconditional Release Waivers cannot be requested on a player while he is on the Bereavement List, Military List, Suspended List, Disqualified List, or Ineligible List. 

A club cannot option a player signed to a "split contract" to the minors if the purpose of the assignment is to release the player and avoid paying termination pay at the "Major League rate."

A player is automatically & immediately removed from his club's Reserve List (40-man roster) and Active List when placed on Unconditional Release Waivers.