2020 updates by Cathy Bickel
Gerbils do molt. The molt from pup to adult sheds out their soft, fuzzy baby fur and replaces it with a smooth and sleek coat. Nutmeg gerbils change color dramatically, from a pumpkin-orange to a brown and black ticked coat.
After that, gerbils molt periodically throughout their lives. There does not seem to be a seasonal or periodic pattern to the molt. During the molt, a visible molt line appears in the coat and moves as the molt progresses. The colorpoint nutmeg gerbil in this picture has many molt lines.