Why do I owe the state money?

Your question has a very broad range of answers available, but most likely you did not have your State deductions set to withdraw enough from your income to pay the proper amount into state taxes (this is very common as many people mistakenly think that once they fill out federal deductions these settings are mirrored for state deductions).

Check with your HR/Personnel department to see how your State Tax deductions are set up and ask what would need to be changed so that you don't have to pay in at tax time (AND while you're at it, you may want to have your federal settings checked as well, just to be sure).