Senior Citizen Property Tax Exemptions A property tax exemption is available for citizens who are 65 or older, and who have lived in their home for at least 10 years prior. The Colorado legislature, not the City and County of Denver, controls the amount of the exemption, and all citizens who have been approved for the exemption in 2008 or in any prior year should see a reduction in the property tax bill they receive in January, 2009.