While I have no real experience with cool season turf, I am with Koester and say that it appears to be dollar spot which we do deal with in our bermudas here. For the most part, we fert them and get it to grow out. In extreme cases, we would spray Clearys or Chipco fungicide. Heritage may be labeled for it but it's expensive and may be overkill. Also, it has been my experience that you never get rid of the disease completely. Those spores are always in the system waiting for conditions to be just right fo them to do their thing. Many of these perfect conditions are beyond your control(rain, humidity, temps)
"The Poor Fish" circa 1930's: The Poor Fish wouldn't have been caught if he'd known enough to keep his fool mouth shut.
"Opportunity is missed by most because it is dressed in overalls and looks like work"- Thomas Edison, businessman/inventor