Mo. Rev. Stat. § 285.730
1. Except as specifically provided in sections 285.700 to 285.750 or in the professional employer agreement, in each coemployment relationship:
2. Except as specifically provided under sections 285.700 to 285.750, the coemployment relationship between the client and the PEO and between each coemployer and each covered employee shall be governed by the professional employer agreement. Each professional employer agreement shall include the following:
(2) A requirement that the PEO shall have responsibility to:
(c) To the extent the PEO has assumed responsibility in the professional employer agreement, to make payments for employee benefits for covered employees.
As used in this section, the term "wages" does not include any obligation between a client and a covered employee for payments beyond or in addition to the covered employee's salary, draw, or regular rate of pay, such as bonuses, commissions, severance pay, deferred compensation, profit sharing, vacation, sick, or other paid-time off pay, unless the PEO has expressly agreed to assume liability for such payments in the professional employer agreement; and
4. Except to the extent otherwise expressly provided by the applicable professional employer agreement:
6. For purposes of this state or any county, municipality, or other political subdivision thereof:
(L. 2018 H.B. 1719)