When you use the term “stealing,” I assume that you mean theft. This is also called “larceny.” These are crimes where you take things that are not yours but you do it without breaking in to a place (burglary) or using or threatening violence (robbery).
If this is what you are talking about, then stealing can be either a misdemeanor or a felony depending on the value of the things that you take.
Different states have different laws about theft. These laws can vary, for example, in terms of how much you have to steal before you move from one class of misdemeanor to another (with progressively harsher punishments) or from a misdemeanor to a felony. You can see in the link below, for example, that in Texas you can steal things that are worth up to $1500 before you can be charged with felony theft.
So, the quick answer to this is that it depends on the state where you live and it depends on how much you steal.