When I was commanding my rifle company my arms room had about enough AN/PAS-13 thermal sights (split between light, medium, and heavy variants) to equip about half my company, and I know that is standard across the army. We usually only mount them on MGs for night missions, but there are plenty to go around if need be. Here's the industry link for the sight:
http://www.raytheon.com/capabilities/products/tws/
Not saying it needs to be added in. I think US Infantry are pretty well modeled already, but each US company does have the equipment (with even more at the HHC in each battalion).