When you initially file a Chapter 13 bankruptcy your Trustee and creditors get a copy of a proposed plan.  This tells the creditors how they are classified in the plan and how much you are estimating that they will be paid for the duration of the bankruptcy.   Both the bankruptcy Trustee and the creditors have the option of reviewing the plan and either accepting or objecting to the plan terms.

Once you file your bankruptcy, your attorney is required to mail a copy of your proposed Chapter 13 plan to all of your creditors within 5 days from the date the case is filed.  This gives everyone who is listed in the plan a chance to review how they will receive payment and whether or not they agree with the plan.  If they do not agree with the plan, they have the right to file an Objection with the court stating their reasoning.  At the 341 Creditor?s hearing (roughly a month after the case is filed), the Trustee will review your plan and have your attorney make any necessary amendments, if he agrees to the plan at that point, he will recommend confirmation.

Confirmation sets your plan in stone and is essentially put in place for your protection.  Once your plan is confirmed, there is no changing it unless a Motion and Order is filed with the court.  This prevents an unsecured creditor from coming up years later stating that they do not agree with the proposed payment.