Rivernorth Managed Duration Municipal Income Fund Inc. is a fixed income mutual fund that invests in the US fixed income markets with a focus on investment grade municipal debt securities, of any maturity. It is managed by RiverNorth Capital Management, LLC and co-managed by MacKay Shields LLC, with a benchmark performance measured against the Bloomberg Barclays Municipal Bond Index. Through the use of fundamental and quantitative analysis and proprietary research, the fund seeks to create a strategic, well-diversified portfolio.