Thanks for writing. There's not much you can do to stop the mushrooms, I'm afraid --- they're there because there's organic matter in the soil. The good news is that the fungus in your ground is actually improving the soil.
Cutting back on how much you water your lawn should reduce the number of mushrooms you see. You can also run a leaf rake through the area with the mushrooms to break them off; once broken, the individual mushroom quickly dies.
---Justin, Senior Garden Editor, BHG.com