The Ohio class SSBNs will soon be replaced in the 2030s by the new Columbia class “boomers”. The first boat is already under construction and should be ready to enter service in 2031. Most of the Ohio class subs are pushing almost 40 years of age. Columbia-class submarine - Wikipedia
The first boat of the Columbia class was renamed the USS District of Columbia,as there is already a USS Columbia in the fleet (SSN 771).