Hello,

Based on what I see in your images, this looks like:

Dollar Spot: More information at tis link:

Dollar Spot - Turf (msu.edu)

OR

Summer Patch: More information at this link:

Summer Patch - Turf (msu.edu)

I highly recommend that you get a confirmed and precise identification of the problem, I recommend you send all your images by e-mail to the MSU Plant & Pest Diagnostics Lab. The experts there can also provide you with the best treatment options. Their email is <personal data hidden> - Please include your name – The lab will let you know if they need a sample sent. FYI – The lab may also ask for additional images too.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details on submitting a sample to MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

Residential Turf

Include a square of turf from the margin of the diseased area so that both healthy and diseased turf is included. Minimally, the turf square should be 6 inches x 6 inches. An intact layer of soil should remain on the root system. Wrap samples in newspaper and pack in a box for shipment. Do not add moisture to the turf prior to shipment. Provide a detailed description of cultural practices (irrigation, fertilization, pesticide application, etc.) and images of the symptoms in the lawn with the sample.

Ship/Deliver Samples Directly to:

MSU Plant & Pest Diagnostics
578 Wilson Road
East Lansing, MI 48824

I hope this helps! Any other questions please ask.