I’m currently under an installment agreement to pay an outstanding tax bill to the IRS. For 2015, I’m owed a tax refund. Can I collect it?

Probably not. As part of the installment agreement, you agreed to have any future tax refunds applied to your outstanding bill. Of course, if the amount of the refund exceeds what you still owe, you’ll satisfy the installment agreement and receive the balance of your tax refund.