Over the past ten years, many studies have noticed a gamma-ray excess at an energy of a few GeV originating from the galactic center. This excess may serve as evidence for dark matter annihilation. A Fermi-LAT collaboration study has characterized many uncertainties of the excess spectrum including possible contributions from Fermi bubbles and millisecond pulsars. The study also discusses the implications for dark matter in light of these uncertainties. In this talk, I will summarize the study by discussing the Fermi Large Area Telescope, how different gamma-ray models affect the excess, and the excess dark matter interpretation.