How long does gumpaste keep if it is in plastic wrap, heavy ziplock and has been in the fridge? I have some for a few months and would like to know if it is still safe to use for modeling a bear for a cake topper.

I guess it depends on your recipe. Mine stays well in the fridge for up to 6 months.
Edna

It is Nick Lodges recipe

How can I tell if it is still good?

You can tell by smell and how it handles. If it is really sticky - it's not good. OR if it has dried out you can try cutting the hard, dry parts off to see what it's like inside.
When you put it away, lightly coat it w/shortening before wrapping it.

Thanks, I will check it and see how it is.

Adding to what cake lady says..if you have an old one, sometimes it wont dry hard.
Edna