Mo. Rev. Stat. § 208.016
In determining the amount of an institutionalized MO HealthNet individual's income that is to be applied to payment for the costs of care in the institution, there shall be deducted a personal needs allowance of no less than thirty dollars per month or the minimum amount required by 42 U.S.C. 1396a(q)(2) if more than thirty dollars. Beginning January 1, 2010, the personal needs allowance shall be increased by an amount equal to the product of the percentage of the Social Security benefit cost-of-living adjustment and the average amount that MO HealthNet participants are required to contribute to the cost of institutionalized care. The annual increase in the personal needs allowance shall be rounded to the nearest whole dollar and shall not exceed five dollars in any year. Once the personal needs allowance reaches fifty dollars, there shall be no further increases unless authorized by annual appropriation.
§ 208.016, RSMo