The court may modify a child support award subsequent to the filing of a motion for modification and upon a showing of a material change of circumstance. The court may not retroactively modify a child support award prior to the date of the filing of the motion for modification. If a party becomes incarcerated, the court may determine that a material change of circumstance warranting a modification of child support has occurred, provided that the party’s ability to pay child support is sufficiently reduced due to incarceration.