Waivers must be secured before certain types of transactions can be completed.
There are two types of waivers (release waivers and assignment waivers), and while there is only one type of release waiver (Outright Release), there are three different types of assignment waivers (Trade Assignment, Optional Assignment, and Outright Assignment). Each type of waivers has a special set of rules that apply.
The MLB waiver list is transmitted at 2 PM (Eastern) every business day. Every day is an MLB business day during Spring Training and the MLB Regular Season, but Saturday, Sunday, and national holidays (Veterans Day, Thanksgiving Day, Christmas Day, New Year's Day, and Dr. Martin Luther King's Birthday) are not considered MLB business days during the off-season, so the MLB waiver list is transmitted at 2 PM (Eastern) Monday through Friday only (not including national holidays that fall on a weekday) during the off-season.
If a club requests a waiver prior to the 2 PM (Eastern) deadline, the waiver request is transmitted that day. If the waiver is requested after 2 PM (Eastern), the waiver request will not be transmitted until the next business day. Any of the other 29 MLB clubs can make a claim while the player is on waivers, and then at 1 PM (Eastern) on the second business day after the waivers are requested the MLB office determines if any claims were made, and if so, which club is awarded the claim.
RESTRICTIONS ON WAIVER REQUESTS:
1. A club can place no more than seven players on waivers per day, and a club can make a maximum of 50 waiver claims per week.
2. A player on a Disabled List cannot be placed on assignment waivers during Spring Training, and a player on a Disabled List cannot be placed on assignment waivers during the MLB regular season until he is both eligible to be reinstated from the DL and healthy enough to play.
3. Neither assignment waivers nor release waivers can be requested on a player while he is on the Bereavement List, Military List, Suspended List, Disqualified List, or Ineligible List.
4. Outright Release Waivers (but NOT assignment waivers) may be requested on a player while he is on the Voluntary Retired List.
5. A player cannot be traded while he is on waivers
6. A player can be on only one type of waivers at any one time.