Abstract: An extendable trim ring for deadbolt locks having a collar slidably mounted in an annular flange. The flange is defined by a tubular wall outwardly-encircled by a protruding lip, and a notch running around the lip. In addition, the rim of the flange is defined by alternately longer and shorter teeth. The annular collar is slidably received within the annular flange. Specifically, the annular collar has a tubular wall seated within the notch of the flange. The inner surface of the collar is defined by a plurality of recessed axial tracks for slidably receiving the alternately longer and shorter teeth of the flange. Thus, the collar can be pulled from the flange (to extract said teeth from the tracks), rotated, and reinserted for pull-and-twist adjustment of the extension of the collar from the flange.