Mo. Rev. Stat. § 454.627

When an order for health benefit plan coverage pursuant to sections 454.600 to 454.645 is in effect, upon termination of the obligor's employment, or upon termination of the health benefit plan coverage, the employer, union or health benefit plan administrator, as appropriate, shall make a good faith effort to notify the obligee, or in IV-D cases, the division, within ten days of the termination date with notice of continuation or conversion privileges. In addition, in IV-D cases, upon termination of the obligor's employment, the employer shall promptly notify the division or IV-D agency of another state, as applicable, of the obligor's last known address and the name and address of the obligor's new employer, if known.