There are some issues with your maple, and the best thing to do would be to have an arborist evaluate it for you and make recommendations. 

It is impossible to determine the cause of the decline from the photo; however there are some observations you can consider as you observe your tree. It may be possible that the tree was not planted at the correct depth. The "flare" is not visible. [More here about planting depth and flares: https://bygl.osu.edu/node/1995 as well as how to plant and care for a tree, such as the importance of doing a soil test before selecting a tree for that spot, along with adequate watering, particularly in hot summer months without adequate rain.]

Also, there is a mound of planting around the base of the tree. Here is some good information about the importance of avoiding volcano mulching, in this article about "volcano mulching," and the sort of problems that can cause over the life of the tree. https://bygl.osu.edu/node/2347

There is little you can do at this point to change the planting depth. It may be helpful to remove the hosta planting at the base and apply organic mulch instead, at the correct depth. 

Here is another possiblity as to why your maple is not leafed out this year: Seedy Maples Make Maples Look Seedy 
https://bygl.osu.edu/node/2343

The hole looks like it was a nest of insects at one time. Whatever the original cause of the wound in the trunk, it too may be causing tree decline. 

Here's another guide to planting and mulching trees. https://extension.unh.edu/resource/planting-and-mulching-trees-and-shrubs-fact-sheet

Finally, here is some information of organic lawncare that may be helpful for improved tree and soil  health, for instance the addition of compost/organic matter to improve soil conditions as well as overall plant health. https://ohioline.osu.edu/factsheet/hyg-4031

Dear Carolyn,

You're most welcome!