Federal Home Shell Tax Credit - Existing homes are eligible for a series of efficiency measures that pertain to the home envelope, worth 30% of the installed cost (materials only, labor is not included in the credit basis). There is a $1,500 cap on the credit per home, including the amount received for heating, cooling, and water heating equipment.
http://www.energytaxincentives.org/consumers/insulation_etc.php

Federal Tax Credit for Heating and Cooling Equipment – Purchasers of highly efficient heating, cooling, and water heating equipment can take tax credits of 30% of installed cost for purchasing qualifying equipment, as detailed below. There is a $1,500 cap on the credit per home, including the amount received for insulation, windows, air and duct sealing.
http://www.energytaxincentives.org/consumers/heating-cooling.php

Missouri Home Energy Efficiency Tax Deduction – deduction of up to $1,000 or $2,000 over two years. Requires an energy audit, which can be part of deduction.
http://www.dnr.mo.gov/energy/residential/homeenergyaudits.htm
Energize Missouri Homes Program Guidelines
click here for the program guidelines

Energize Missouri Homes Program - Other energy efficiency and weatherization assistance information is available at the Energize Missouri Homes page at
http://www.dnr.mo.gov/transform/energizemissourihomes.htm

Most utilities have energy efficiency grants and rebate programs. Check with your local utility.

Weatherization Grants for Low Income Families – Program hires contractors to do weatherization improvements to low income (below 200% of poverty level) homes. Amounts can be as high as $6,500:

• Jackson, Clay, Platte Counties – KCMO Property Preservation
  http://ww4.kcmo.org/neigh.nsf/web/weather_app?opendocument

Other resources – Additional information can be found at the following web sites:

• Mid America Regional Council's recovery web site at
  http://www.marc.org/Recovery/Energy/consumerloans.asp
• Metropolitan Energy Center web site at
  (http://www.kcenergy.org/).
• DSIRE - Database of State Incentives for Renewables & Efficiency website at
  http://dsireusa.org/incentives/index.cfm?re=1&ee=1&spv=0&st=0&srp=1&state=MO