Abrothallus nephromatis is a widely distributed species of lichenicolous fungus in the family Abrothallaceae. It was formally described as a new species in 2015 by Ave Suija and Sergio Pérez-Ortega. The type specimen was collected near Dawson Falls in Wells Gray Provincial Park at an elevation of about 800 m (2,600 ft), where it was found on a Nephroma parile lichen that itself was growing on a dead trunk of birch tree. The species epithet refers to the host genus, Nephroma.