Rivernorth Managed Duration Municipal Income Fund Inc. is a closed ended fixed income mutual fund launched and managed by RiverNorth Capital Management, LLC. The fund is co-managed by MacKay Shields LLC. It invests in the fixed income markets of the United States. The fund primarily invests in investment grade municipal debt securities. It seeks to invest in securities of any maturity. The fund employs a combination of fundamental and quantitative analysis. It benchmarks the performance of its portfolio against the Bloomberg Barclays Municipal Bond Index. The fund employs proprietary research to create its portfolio. Rivernorth Managed Duration Municipal Income Fund Inc. was formed on July 26, 2019 and is domiciled in the United States.