Meat tends to last in the freezer for a long time. You can probably keep it safely in there for 3-6 months. The more important thing is how you thaw it. You should put frozen chicken in the fridge or the microwave, don't leave it out on the counter or it could get bacteria.
Frozen chicken remains edible indefinitely, though (assuming no air pockets in the packaging) the taste will suffer after about 9 months for parts or a year for a whole chicken.
