According to Alexandr Leonov, the General Director and General Designer of NPO Mashinosroyeniya (NPO Mash, the old Chelomey design bureau), quoted by TASS, the service life of UR-100NUTTH/SS-19 missiles is still being extended. The missile has been in service since 1979 (Leonov said 49 years, but that would be UR-100N, which was indeed began service in 1975.)

The last public report about service life extension for UR-100NUTTH was in 2014 - at that time the service life was extended to 36 years. Another report, in 2020, mentioned that there was another extension in 2019, but it was the same 36 years, so it wasn't really a change from 2014. The same 2020 report mentioned a life extension at the time, but that request was about UR-100NUTTH missiles used as Avangard launchers. These about 30 missiles, received from Ukraine in the early 20000s, are different in that they have not been fueled and therefore begin their service just now.

At the time the START treaty expired in 2009, Russia had 41 deployed UR-100NUTTH in Tatishchevo and 29 in Kozelsk (these are the last official data). Both divisions, however, were bing converted to Topol-M and Yars. It appears that all old missile have been removed from Kozelsk, but it's possible that some, maybe 10 or 20, are still deployed in Tatishchevo. It's possible that while the missiles are still in silos, their warheads have been removed - a similar thing was done back in the 1970s with their predecessor, UR-100, when that missile reached the end of its service life.