BlackRock MuniYield Quality Fund III, Inc. is a closed ended fixed income mutual fund launched by BlackRock, Inc. It is co-managed by BlackRock Investment Management LLC and BlackRock Advisors, LLC. The fund invests in fixed income markets. It invests primarily in a portfolio of long-term investment-grade municipal obligations. BlackRock MuniYield Quality Fund III, Inc. was formed in 1992 and is domiciled in United States.