The agreement, yet to be ratified by the Associate of Flight Attendants union members, is also the first to make boarding pay legally binding for unionized flight attendants, the union said on Tuesday.
Flight attendants in the U.S. are usually paid an hourly rate after the flight cabin doors close and it does not include the time taken to onboard passengers.
"With boarding pay, we achieve significant pay increases," the union said.
Alaska Airlines did not immediately respond to a request for comment.
The new three-year tentative contract comes at a time when pilots and flight attendants across U.S. airlines have been demanding better pay and benefits after the pandemic brought the industry to a standstill and the subsequent pent-up travel demand led to record profits for airlines.
In February, Alaska Airlines' flight attendants authorized a strike mandate for the first time in three decades.
The tentative labor agreement, which avoids a potential strike, includes benefits such as improvements to holiday and overtime pay as well as 20 months of retroactive pay.
Voting for the ratification of the deal will take place later this month, and end on Aug. 14.
