GEOTHERMAL GROUND-COUPLED HEAT PUMP TAX CREDIT. HB 375, signed in April 2009, created a tax credit in New Mexico for geothermal heat pumps purchased and installed between January 1, 2010 and December 31, 2020 on property owned by the tax payer. The credit is worth 30% of the system's cost up to $9,000 and can be applied to individual or corporate income taxes. Any unused credit may be carried forward for up to 10 years.