On February 17, 2009, President Obama signed a stimulus bill (The American Recovery and Reinvestment Act of 2009) that made some significant changes to the energy efficiency tax credits. The highlights are:

• The tax credits that were previously effective for 2009, have been extended to 2010 as well.
• The tax credit has been raised from 10% to 30%.
• The tax credits that were for a specific dollar amount (ex $300 for a CAC), have been converted to 30% of the cost.
• The maximum credit has been raised from $500 to $1500 for the two years (2009–2010). However, some improvements such as geothermal heat pumps, solar water heaters, and solar panels are not subject to the $1,500 maximum.
• The $200 cap on windows has been removed.