MFS Municipal Income Fund R6 

This fund typically allocates at least 80% of its net assets to securities and other holdings that generate income exempt from federal taxation. However, the interest earned on these investments could still be subject to the federal alternative minimum tax (AMT). Its investment strategy primarily centers on municipal instruments. The fund retains the option to allocate 25% or more of its total assets to municipal debt used to finance similar types of undertakings, such as those connected to education, healthcare, housing, public utilities, water, or sanitation systems.