Melber was already expected to take over the hour, which had previously been anchored by Greta Van Susteren.
Melber will also take on a new role, serving as a legal analyst for NBC News, and contributing to the various outlets of the NBCUniversal-owned unit, including its “Today” morning show.
Melber, who initially joined MSNBC as a contributor, has served as a frequent fill-in host for primetime anchors Chris Hayes, Rachel Maddow and Lawrence O’Donnell. He had been hosting “The Point,”a Sunday afternoon program. MSNBC is expected to continue to air live programming at that time, though it has not named an official anchor for the weekend slot. Melber is a former lawyer and won an Emmy for MSNBC for his coverage of the Supreme Court.