groupmod

Change the group name

$ sudo groupmod -n [new_group] [group_name]

$ sudo groupmod -g [new_id] [group_name]

groupmod [options] group

groupmod modifies the attributes of an existing group on the system. It can change the group name, group ID (GID), or group password.
When changing GID, files owned by the group are NOT automatically updated. You must manually find and update file ownership using commands like find / -gid OLDGID -exec chgrp NEWGROUP {} \;.
Changing a group name has no effect on file ownership since files reference groups by GID, not name.

-g, --gid GID

Change group ID to GID

Change group name to NAME

Allow non-unique GID

Set encrypted group password

Apply changes in chroot environment

Apply changes in prefix directory

Changing GID does not update file ownership automatically. Users must log out and back in for group changes to take effect. Cannot change a group to a name or GID that already exists (unless -o is used for GID).

groupmod is part of the shadow-utils package, which has been the standard for Unix group management across Linux distributions. It provides safe modification of the /etc/group and /etc/gshadow files.

groupadd(8), groupdel(8), gpasswd(1), usermod(8)