Doris and Raoul Hagens 1976 divorce decree awarded a percentage of Raouls military retirement pay to Doris to be paid if, as, and when he received it. After Raouls subsequent retirement from the Army, he was determined by the Veterans Administration (VA) to have a service-connected disability. He then elected to be paid VA disability benefit payments, which are not subject to federal income taxes, in place of part of his military retirement payments, which are subject to income taxes. Raouls election reduced the amount of military retirement pay he received. When Doris began receiving her percentage of the reduced Army retirement pay Raoul received, she sought enforcement and clarification of the divorce decree. The trial court determined that the decree divided only the military retirement pay being received by Raoul, it did not divide his VA disability benefits, and Doris was entitled to only a percentage of the military retirement pay. The court of appeals reversed. The appeals court held that the trial court modified the 1976 decree instead of clarifying it, and the modification was barred by res judicata principles. ___ S.W.3d ___, ___. We hold that the trial court correctly clarified the unambiguous original decree, and its action was not a modification barred by res judicata principles. We reverse the court of appeals judgment and affirm the judgment of the trial court.