A bill to amend the Internal Revenue Code of 1954 to clarify the definition of geothermal energy, and for other purposes.

Amends the Internal Revenue Code to define "geothermal energy" as the natural heat of the Earth at any temperature. (Present regulations require that such heat must exceed a specified temperature.)

Qualifies for the residential energy tax credit and the investment tax credit for energy property an energy system which uses both geothermal energy and another energy source not eligible for such credits if geothermal energy provides more than 80 percent of the energy for such system.

Qualifies for the investment tax credit for energy property an energy system which uses both geothermal energy and another energy source eligible for such credit (such as biomass, solar, wind, ocean thermal, or hydroelectric) if the combination of such energy sources provides more than 80 percent of the energy for such system.

Provides that in the case of a taxpayer who claimed a geothermal credit on a return for any taxable year beginning before January 1, 1984, in reliance on the advice of an employee of the Internal Revenue Service that such credit would be allowable, the amendments made by this section shall apply for purposes of determining whether such credit is allowable.