Teams can keep up to 16 players on their practice squad.
Six of the players can have more than two accrued seasons meaning the majority are young aspiring players. An accrued season is when a player is on the roster, PUP or IR for at least six games during a single season.
Once a player is released they can then choose to sign with any teams practice squad. If they have less than four accrued seasons they need to clear waivers first, if they have more they aren't subject to waivers until after the trade deadline. So you have no control over getting a player to your practice squad, they can leave if they feel they have a better chance to make a 53 man roster elsewhere.
Other teams can steal your players throughout the season, provided they decide to leave and are signed to that team's 53-man roster. It can't be from teams you are due to play that week. During Covid, the NFL added a rule saying players can be protected from Tuesday for half a week. This no longer exists.
If you steal a player from another teams practice squad, you need to pay them for at least two weeks on your 53 man roster, they don't need to remain on your roster for those two weeks.
They are paid $13,000 a week/$234,000 a year unless they have more than two accrued years, then it is between $17,500 a week/$315,000 a year and $22,000 a week/$396,000 a year. This cost is counted against the teams salary cap. So as a maximum your practice squad will cost $4.716m, which is 1.7% of the 2025 salary cap.
Players can be elevated three times in a season, they then would need to be signed to the teams 53 man roster to play again that season. This used to be only two times in a season before.
If a player is called up to the roster they are paid at the minimum cost of a player, not a practice squad wage for the one week.
Teams can have an extra space on the practice squad due to a player on the international player pathway, in the past the Cleveland Browns have used this for Roy Mbaeteka. Kilian Zierer was designated as their International Pathway Player but he has instead signed with the San Francisco 49ers practice squad.