Sherri, 
Thank you for reaching out. What insect are you hoping to treat for? Unfortunately I am not aware of any programs that are in place to help mitigate the cost of treatment for Emerald Ash Borer. Other boring insects and pests of ash have been common for many years and so there are not funds available there either. If you are planning to keep your tree it is important to treat it for Emerald Ash Borer. This is because the tree can become hazardous if it dies from EAB which it will do without treatment. 

In case you are asking about EAB here is some more information: 

You can look on the ISA (International Society of Arboriculture) website https://www.treesaregood.org/findanarborist to find a certified arborist who can do the treatment if your tree is over 15" in diameter at your chest. If it is smaller you can use Bayer Tree and Shrub as a soil drench, just be aware not to use it when there are flowering plants in the area you are treating. 

Here is a guide to treatment options: https://www.emeraldashborer.info/documents/multistate_eab_insecticide_fact_sheet.pdf. Most arborists are going to use emamectin benzoate which is a trunk injection that is good for 2 years, although some stretch it to 3 years. 

If you are seeing damage on the trunks from Lilac Ash borer, the emamectin benzoate treatment should work for them as well, although it is rare that LAB will kill an ash tree unless it is very stressed. 

I'm happy to talk in more detail if you would like, good luck!