In some examples, a method includes identifying a damaged area in a ceramic matrix composite coating of an in-service component; applying a restoration slurry to the damaged area of the ceramic matrix composite coating, wherein the restoration slurry comprises a liquid carrier and a restoration coating material; drying the restoration slurry to form a dried restoration slurry; and heat treating the dried restoration slurry to form a restored portion of the ceramic matrix composite coating. In some examples, an assembly may include a component including a substrate and a coating on the substrate, where the coating defines a damaged portion; masking around the damaged portion on undamaged portions of the coating; and a restoration slurry in the damaged portion, wherein the restoration slurry comprises a liquid carrier and a restoration coating material.