Mo. Rev. Stat. § 135.335: Credit reduced, amount, when.

In the year of adoption and in any year thereafter in which the credit is carried forward pursuant to section 135.333, the credit shall be reduced by an amount equal to the state's cost of providing care, treatment, maintenance and services when:

(1) The child is placed, with no intent to return to the adoptive home, in foster care or residential treatment licensed or operated by the children's division, the division of youth services or the department of mental health; or

(2) A juvenile court temporarily or finally relieves the adoptive parents of custody of the child.