Well, that would depend if you are fostering for an organization. If so, then they may have their own rules and rules will vary between different groups. When I fostered for the Hawaiian Humane Society back in high school there was a trial period during which you were not allowed to adopt the kitties you fostered. I think it was about 3 months or so. After that you could adopt a kitty you fostered but you had to go through the same process as everyone else.

Are you considering fostering? It is very rewarding!

There are lots of PTers who are very knowledgeable about fostering so feel free to ask any questions you may have!