On January 5, 2009 the Montreal Impact announced that Biello and veteran midfielder Patrick Leduc had both accepted contract extensions for the 2009 season. During the 2009 USL season Biello contributed by helping the Impact clinch a playoff spot under new head coach Marc Dos Santos. He helped the Impact reach the finals where Montreal would face the Vancouver Whitecaps FC, this marking the first time in USL history where the final match would consist of two Canadian clubs. In the final Biello helped the Impact win the series 6–3 on aggregate. The victory gave the Impact their third USL Championship and also the victory marked Biello's third USL Championship. Once the season came to a conclusion Biello announced his retirement from competitive soccer on November 19, 2009.