How do you know if a Goodman gas furnace is energy-efficient?

Goodman gas furnaces are rated for efficiency using the Average Fuel Use Efficiency criteria by the Air Conditioning, Heating and Refrigeration Institute. High AFUE ratings indicate a furnace with high efficiency that may qualify for tax credits.

A gas furnace's AFUE rating indicates the relative amount of input energy from gas fuel that is converted to usable heat, with a rating of 100 indicating the theoretical maximum possible efficiency. The AHRI currently lists 68 Goodman gas furnace models with AFUE ratings of 95 percent or better as of 2015; this level of AFUE is considered a benchmark for the most efficient gas furnaces on the market today.