After a final order of child support is entered, either party may seek a modification at any time based on a substantial change in circumstances that has made the original order unfair and improper. A party may also seek a modification if more than three years has passed since the date of the final order without a need to show a substantial change in circumstances.  

Cases are always fact specific, and your situation may be different then the examples laid out here. Situations vary by income, expenses, new children and stepchildren, distance between the homes, or special needs of a child. The court hearing your case will examine the specific factual circumstances of your family to determine whether there has been a substantial change in circumstances that make the original order improper or unfair. Therefore, it is important to succinctly and accurately make your case for the modification.

Examples of situations that could warrant modification include:

  • Involuntary loss of employment.
  • Reduction or increase in income
  • Change in residential responsibility or parenting time.
  • Child graduating from high school or turning 18, while younger still children still require child support.
  • A parent returning to school. In Re Lynn.

There are several circumstances that the New Hampshire Supreme Court has ruled that modification of child support should be denied. Some of the circumstances include:

  • A parent’s relocation itself, without more evidence, is not a substantial change in circumstances sufficient to modify child support. In Re Adams.
  • The remarriage of either party does not as a matter of law warrant a modification of child support. Peterson v. Buxton.
  • Absent other circumstances, the expected growth of a child and normal cost of living increases are not substantial chances or special circumstances that justify modification. Morrill v. Millard.


Once a child support order has been approved by the court the modification statute, NH RSA 458- C:7, allows for a petition to modify the child support order after three (3) years have passed. If one party petitions for a modification before the three year mark they must show a substantial change in circumstances that makes continuing the original order improper and unfair.

The NH supreme court released an opinion on In the Matter of Lynn and Lynn on April 24, 2009 which deals with the substantial change in circumstances standard. In this case, when the Mother and Father got divorced, two children began residing with Father and one child with Mother. Mother became obligated to pay child support at a rate that deviated from the guidelines due to her limited income. Less than 3 years later, Mother petitioned to modify her child support obligation because she had been accepted to nursing school and was going to have to work part-time. The court granted the modification and ceased all obligations to pay child support.

The trial court specifically found that the Mother’s income while in school was a substantial change in circumstances and that even though the Mother is voluntarily underemployed it is only one factor to consider whether or not modification is warranted.

The Father appealed the decision to discontinue child support. The Father argued that by choosing to go to nursing school the Mother was voluntarily underemployed and therefore she should still be required to pay the child support. The NH Supreme Court held that the trial court followed the statute and therefore the trial court did not err in modifying the child support.

However, the court warned that this particular case is not meant to imply that a parent is entitled to reduced child support obligation whenever the parent has voluntarily reduced his/her income to attend school. The court mused that there could be circumstances when a parent goes back to school voluntarily and even with decreased income they must still pay the initial child support amount.

Marisa L. Ulloa, Crusco Law Office, PLLC Law Clerk, contributed to this post.