AbstractCircular polarization ratio (CPR) measurements from the Miniature Radio Frequency (Mini‐RF) instrument provide information about how lunar craters evolve with time. In particular, S‐band CPR data are sensitive to the rockiness and/or topographic roughness of the uppermost ~1 m of the subsurface. We extracted CPR as a function of radial range for 6,206 unique craters superposed on the lunar maria with diameter D = 0.8–2 km and constructed median profiles aggregating craters into 13 different age classes. These aggregate profiles show systematic evolution of craters' CPR with time. The freshest craters (<200 Ma) have ejecta exhibiting elevated CPR compared to the background maria out to distances of more than three crater diameters beyond the craters' rims. The extent and magnitude of this enhancement declines as craters age. Within crater interiors, the CPR signature initially increases for 0.4–0.6 Ga and then declines. These observations provide constraints on rock breakdown and regolith development after crater formation. Additionally, our results demonstrate that the CPR evolution of crater interiors and ejecta are significantly decoupled. The CPR enhancement in crater ejecta fades faster than crater interiors, causing their overall CPR signature to look similar to anomalous craters whose interior CPR anomalies have been attributed in past work to the presence of water ice. Craters in this study became more anomalous‐looking as they reach middle age (~1.5–2.5 Ga), as their interior and exterior regolith differ in rockiness as time passes. Our results support, but do not prove, that anomalous craters' CPR signatures can arise without requiring water ice.