Hi, 

I do not see any of the leaf spotting or black stem lesions that would indicate that this is due to boxwood blight. 

https://www.canr.msu.edu/home_gardening/uploads/files/2019_msue_fact%20sheet_boxwood_blight_final.pdf

Rather, it looks as if your plants are being severely damaged by box tree moth, a new invasive pest species that showed up in southeast Michigan last year. Unfortunately, this pest is equally as troublesome as boxwood blight.

https://www.canr.msu.edu/ipm/uploads/files/Box%20Tree%20Moth%20Identification.pdf

Unfortunately, once this pest has found your plants, they can complete 2-3 lifecycles per year and would need repeated treatment throughout the growing season. You may want to consider replacing your boxwoods with other landscape plants if you do not want to have to regularly treat for this pest.

"Treatment is recommend in late July and early September using an application of bifenthrin (several ready-to-use products available at the garden center) or any pyrethroid insecticide for homeowner use can be used to control all life stages. Pyrethroid insecticides are those where the active ingredient ends in thrin, for example, cyfluthrin, permethrin, resmethrin, cypermethrin, lambda-cyhalothrin and sumithrin.

Alternatively, homeowners can spray a Bacillus thuringiensis (Bt) product once every two weeks. However, Bacillus thuringiensis is not an effective control for larger caterpillars, eggs or adults. Bt is a bacterium that kills insects when ingested. There are subspecies of Bt that affect specific types of insects; kurstaki is the subspecies that specifically target caterpillar larvae. Look for product labels that say Bacillus thuringiensis subsp. kurstaki (Btk)."

You can read more about this emerging issue here:

https://www.canr.msu.edu/news/what-the-box-tree-moth-quarantine-means-for-michigan-homeowners

Here are some options for boxwood alternatives. MSU Extension is hoping to put out our own article on this topic soon: 

https://cals.cornell.edu/new-york-state-integrated-pest-management/outreach-education/fact-sheets/box-tree-moth/alternatives-boxwood