Missouri like all states is eligible for the federal income tax credit which covers 22% of the total cost of your system installed before December 31st, 2021. It is important to ensure that you have enough taxable income for this to apply. Missouri also has a rebate program in place via senate bill 564 that requires all utility corporations to give homeowners a rebate of twenty-five cents per watt ($0.25/W) up to a twenty-five kilowatt (25 kW) system for residential customers.
Note: Net metering policies vary in many areas and by utility providers so be sure to ask your solar energy expert which one applies to your home.
Attached is the link where you can find more info through each individual utility companies public filings.
Missouri Department of Natural Resources: Division of Energy