Hello Julie,

Your phosphorus levels in both the front yard and back yard are high. This reference has some suggestions for reducing excessive phosphorus: https://ask2.extension.org/kb/faq.php?id=749014

If you regularly apply any organic matter to your soil/lawn, stop. That increases phosphorus. For your lawn, apply nitrogen fertilizers without any phosphorus content. It is a Michigan state law that no fertilizer applied to established lawns can have any amount of phosphorus in them.

Both the front yard and back yard are low in potassium. The soil test results show recommendations for added potassium:

Backyard 2.4 lbs per 1000 sq ft

Front yard 3.4 lbs per 1000 sq ft

Your best choices to increase your potassium are Muriate of Potash (KCl: 0-0-60 to 0-0-62) and Potassium sulfate (0-0-50 to 0-0-52). Then use an all nitrogen or nitrogen/low potassium fertilizer for the required added nitrogen. If you can find the Potassium and Nitrogen fertilizers you plan to use or can use, write back with their chemical makeup (X-X-X) and we can give you the amount of each fertilizer necessary to meet the suggestions from your soil test.

Onto the fungus. Identifying a fungus from a photo alone is very difficult. Your pictures seem to be consistent with pink patch disease. This article describes pink patch disease and treatment. https://extension.psu.edu/turfgrass-diseases-pink-patch-causal-fungus-limonomyces-roseipellis

For most lawns, the damage caused by the fungus does not kill the grass and the grass will regrow when the conditions for the fungus are no longer favorable. Except in rare cases, no treatment is suggested for Pink Patch – let the infection run its course.

Hope this helps.