​This appears to be Northern Tooth Fungus, but I would need to look at it more closely for certain identification. This fungus causes a heart rot on maples and other trees. In most cases, the tree has to be tested for the extent of the decay. Presence alone of the fruiting bodies is usually not reason for removal; however, it should be reviewed by a certified arborist for risk assessment.

Resources
Northern Tooth Fungus-Climacodon septentrionale, Department of Biology, University of Wisconsin
Indiana Certified Arborists, International Society of Arboriculture

Lindsey Purcell, Urban Forestry Specialist
Department of Forestry and Natural Resources, Purdue University