T. Rowe Price High Yield Municipal Bond Fund 

This fund aims to generate a substantial level of income that is exempt from federal income taxes. It achieves this primarily through investments in long-term municipal bonds with credit ratings ranging from lower to upper-medium grade. Typically, a minimum of 80% of the income distributed by the fund will qualify for federal tax exemption. However, investors should be aware that up to 20% of the income might be derived from securities subject to the Alternative Minimum Tax. The strategy generally involves seeking municipal bonds that offer higher yields, including those categorized as "non-investment grade" (rated BB or lower by a major credit rating firm or by T. Rowe Price), which are commonly known as "junk" bonds.