Once your Chapter 13 plan is confirmed, you and all of your creditors, are bound by its terms. Creditors are bound even if they are not provided for in the plan.
Bankruptcy Procedure Rule 1327 states:
(a) The provisions of a confirmed plan bind the debtor and each creditor, whether or not the claim of such creditor is provided for by the plan, and whether or not such creditor has objected to, has accepted, or has rejected the plan.(b) Except as otherwise provided in the plan or the order confirming the plan, the confirmation of a plan vests all of the property of the estate in the debtor.(c) Except as otherwise provided in the plan or in the order confirming the plan, the property vesting in the debtor under subsection (b) of this section is free and clear of any claim or interest of any creditor provided for by the plan.