The Colony Group a wealth and business management firm in Boston that manages $13 billion, is expanding its presence in Massachusetts with the acquisition of Derby and Company, a financial services firm based in Newton, Mass., the company announced Monday.

With the completion of the transaction, Colony will have 20 offices and more than 300 team members. The acquisition is the fifth the firm has made since July.

Derby & Company, which was founded in 1987 by Burt Derby, serves entrepreneurs and professionals. Burt’s sons, Mark and Jonathan, later joined the firm and both join Colony as principals and senior wealth advisors.