Section 458-C:7 - Modification of OrderI.(a) The obligor or obligee may apply to the court or, when the department of health and human services has issued a legal order of support pursuant to RSA 161-C, to the department, whichever issued the existing order, for modification of such order 3 years after the entry of the last order for support, without the need to show a substantial change of circumstances. This section shall not prohibit the obligor or obligee from applying at any time for a modification based on substantial change of circumstances.(b) Not less than once every 3 years the department shall provide notice to the parties subject to a child support order payable through the department informing them of their right to request a review, and, if appropriate, the right to apply for adjustment of the child support order. The notice provision may be included as part of the initial support order or any subsequent orders.(c) Not less than once every 3 years the department shall review all child support orders in which there is an assignment to the department pursuant to Title IV-A of the Social Security Act and, if appropriate, apply for adjustment of the child support order in accordance with the child support guidelines.II. Any child support modification shall not be effective prior to the date that notice of the petition for modification has been given to the respondent. "Notice" means: (a) Service as specified in civil actions; or(b) Acceptance of a copy of the petition, as long as the petition is filed no later than 30 days following said acceptance, and as long as the petitioner provides proof of acceptance by a certified mail receipt. Nothing in this subparagraph shall be construed to affect service as required by law.III. Whenever the court, pursuant to this chapter, modifies a support order which results in an overpayment of support, the court shall order, absent a showing of undue hardship, the obligee to directly reimburse the obligor for such overpayment of support or order an adjustment to the modified support order until reimbursement of the overpayment has been satisfied. Any reimbursement ordered shall be only for an overpayment that occurs after the date that notice of the petition for modification of support order was given to the respondent. The court shall enter an order for reimbursement as a provision of the modified order, which order for reimbursement shall take effect 30 days after issuance, unless either the obligor or obligee requests, within such 30-day period, a separate hearing to determine the amount and frequency of reimbursement.1991, 233:1. 1995, 310:175, 181. 2004, 169 : 1 . 2007, 274 : 1 . 2009, 101 : 1 , eff. June 15, 2009.