In Re the Marriage of: Judith Ann Tait, petitioner, Respondent, vs. Gerald Allen Tait, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C0-97-1867

Cheryl Ann Seeman, petitioner,

Appellant,

vs.

Scott Earl Seeman,

Respondent.

 Filed March 17, 1998

 Affirmed

 Harten, Judge

Hennepin County District Court

File No. DC84237

David T. Erickson, 7301 Ohms Lane, Suite 345, Edina, MN 55439 (for appellant)

Richard J. Schieffer, Johnson & Woods, P.A., 1055 East Wayzata Boulevard, Suite 300, Wayzata, MN 55391 (for respondent)

Considered and decided by Short, Presiding Judge, Amundson, Judge, and Harten, Judge.

 U N P U B L I S H E D O P I N I O N

 HARTEN, Judge

Cheryl A. Seeman appeals a post-judgment order denying her motions to extend child support until the child completes secondary school and to modify support retroactively because of respondent Scott E. Seeman's failure to provide income information. Because appellant did not demonstrate that the child is unable to provide self-support, and because appellant failed to raise the retroactive modification issue in a prior proceeding, we affirm.

 FACTS

The parties' two-and-a-half-year marriage was dissolved by a stipulated judgment entered on May 4, 1981. The judgment awarded custody of the parties' child (born September 19, 1979) to appellant and directed respondent to pay 20% of his net wages as child support, with a cap of $200 per month. The judgment provided that support shall continue "until the child reaches majority, is emancipated, or until further order of this court." Finally, the judgment directed respondent to provide appellant with proof of his net earnings every six months.

On September 16, 1988, the district court ordered respondent's child support obligation increased to $300 per month, pursuant to the parties' stipulation. Although the parties' stipulation did not address the duration of respondent's support obligation, the August 26 order directed that support continue until the parties' child reaches her majority, is emancipated, or until age 20 if the child is still in high school.

On February 28, 1996, Hennepin County Collections Services Division (the county) began a review of respondent's support obligation and directed the parties to submit financial information. In a March 5, 1996, affidavit, appellant indicated that she believed respondent earned a substantial salary at his current employment at Discover Plastics. On May 22, 1996, the county submitted to the parties a proposed modification order increasing support to $1,225 per month based on respondent's 1995 earnings of $99,515.

Respondent rejected the proposed order and requested a hearing. On July 30, 1996, the parties appeared without counsel before an administrative law judge (ALJ). By order dated September 11, 1996, the ALJ directed respondent to pay $1,125 per month in child support commencing June 1, 1996. The order directed child support to continue until the child reaches majority, is emancipated, or until age 20 if the child is still in high school.

Appellant retained counsel and filed a motion for "reconsideration" on November 1, 1996. The affidavit in support of the motion indicated that the September 11, 1996, order was in error because modified support should have commenced as of March 1, 1996. The affidavit indicated that respondent had the same job for over five years and had failed to supply income information to appellant as directed by the 1981 judgment. By order dated January 24, 1997, the ALJ denied the motion.

In December 1996, respondent, now represented by counsel, appealed the provisions of the September 16, 1988, and September 11, 1996, orders extending his support obligation until the parties' child graduates from high school or reaches age 20. We reversed, holding that the orders resulted from an unauthorized application of Minn. Stat. § 518.54, subd. 2, to the parties' 1981 dissolution judgment, and that no findings were made justifying an extension of child support due to the child's inability to be self-supporting. Seeman v. Seeman, No. C2-96-2489 (Minn. App. May 20, 1997) (Seeman I). Appellant did not petition for review, and this court's decision became final when judgment was entered on June 26, 1997.

In August 1997, appellant filed a motion to require respondent to pay child support until the parties' child graduates from high school in June 1998 and for retroactive modification of support to reflect respondent's increased income since 1992. This appeal followed the district court's order denying the motions.

 D E C I S I O N

  1. Support Until Graduation from High School. Unless a court order provides otherwise, child support terminates automatically upon emancipation of the child as provided in Minn. Stat. § 518.54, subd. 2. Minn. Stat. § 518.64, subd. 4a (1996). The statute in effect at the time of the parties' dissolution defined "child" as

an individual under 18 years of age or an individual who, by reason of his physical or mental condition, is unable to support himself.

Minn. Stat. § 518.54, subd. 2 (1980).

Our opinion in Seeman I did not preclude a motion to extend the duration of respondent's support obligation on the ground of the inability of the parties' child to be self-supporting. Appellant argues that the child is disabled by "legislative act," because the statute requiring a child to be at least six years of age on September 1 before entering first grade precluded the parties' child from completing high school before reaching age 18. In her affidavit in support of the motion to extend child support, appellant states that the parties' child attends high school from 7:50 a.m. to 2:50 p.m. and then has to study. The affidavit indicates that the child participates in volleyball and softball and is an honors student.

The requirement of inability to provide self-support is not met simply because the child is still a full-time high school student. Borich v. Borich, 450 N.W.2d 645, 648 (Minn. App. 1990). The child's demonstrated inability must extend beyond an "inability" that results solely and inevitably from the child's continued enrollment in high school. Id.

Here, there is no showing that the parties' child is unable to support herself, except that the child is not employed full-time due to the time she spends attending high school classes, participating in sports, and studying. Because the child's claimed inability results solely from her continued enrollment in high school, the district court did not abuse its discretion in denying appellant's motion to extend child support.

Appellant also argues that the 1981 judgment authorizes an extension of child support, because the judgment directs child support to continue until the child has reached majority, is emancipated, or "until further order of the court." Because we held in Seeman I that an extension of respondent's support obligation was not authorized absent a finding of the child's inability to support herself, appellant is precluded from raising this issue. See Brezinka v. Bystrom Bros., Inc., 403 N.W.2d 841, 843 (Minn. 1987) (issue determined in first appeal will not be relitigated in district court nor reexamined in a second appeal).

  2. Retroactive Child Support. The decision to modify child support lies within the broad discretion of the district court, and an appellate court will reverse only when it finds a clearly erroneous conclusion that is against logic and the facts on record. Moylan v. Moylan, 384 N.W.2d 859, 864 (Minn. 1986). The court may modify child support only after a party shows a change of circumstances, such as substantially increased earnings of a party, that makes the existing order unreasonable and unfair. Minn. Stat. § 518.64, subd. 2(a) (Supp. 1997).

Generally, the court may order retroactive modification of child support only to the date of service of the motion to modify the existing support order. Minn. Stat. § 518.64, subd. 2(d) (Supp. 1997). But modification may be applied to an earlier period if the court makes express findings that the party seeking modification was precluded from serving a motion for certain reasons, including a material misrepresentation of another party, and that the party seeking modification, when no longer precluded, "promptly" served a motion. Id. (emphasis added).

An obligor's failure to provide pay stubs and tax records as required by the dissolution judgment may constitute material misrepresentation and provide basis for the court to consider a retroactive increase of child support for a period prior to the filing of the motion to modify. Johnson v. Johnson, 533 N.W.2d 859, 866 (Minn. App. 1995). In this case, respondent failed to provide appellant with information regarding his income as directed by the 1981 judgment.

Although appellant was aware of respondent's increased income at least by May 22, 1996, when the county served a proposed modified support order, appellant did not bring her motion to retroactively modify support until August 1997. Appellant thereby failed to meet the statutory requirement to "promptly" serve a motion when no longer precluded by the other party's material misrepresentation. See Minn. Stat. § 518.64, subd. 2(d)(1).

  Affirmed.