Agents are often hired to negotiate the baseball contracts of professional players. These agents work on behalf of the players and argue for higher compensation and more perks in a player's contract. They are paid a fee for their services. The baseball contracts of professional athletes often come with a signing bonus. A signing bonus is guaranteed upfront money that is paid to a player when he signs a baseball contract. This bonus is in addition to the player's yearly salary with the team, and a bonus often tops well over a million dollars for sought after players. Other bonuses may be negotiated by agents. Players may receive money in addition to their annual salary for good performance, or for reaching specific milestones or goals. Baseball contracts are sometimes guaranteed contracts, which means that a player is guaranteed the money promised to him in the contract. Terminating a guaranteed contract early may require a fee to be paid by the team, or in some cases the player's salary must continue to be paid in full.