Apparently this had been known by some fans for a while, but it was only today that KryptonSite had received confirmation from the studio on this: Supergirl Season 5 will be only 20 episodes long.
This is not entirely surprising, as The CW only has so many time slots for more shows than they have slots for, and other series such as DC’s Legends of Tomorrow and Black Lightning also have shorter runs.
This is the second time Supergirl has ended a season at 20; the first season which aired on CBS was also capped at 20 episodes.
Fortunately, we have 7 episodes left to enjoy in Season 5, which is more than a third of a season – Supergirl returns with “The Bodyguard” on March 8.