This strategy is inherent in the American Century Diversified Municipal Bond ETF (TAXF), which seeks to provide consistent tax-free income by employing an active, research-driven process that draws from across the muni bond universe and adjusts exposure depending on prevailing market conditions. With regard to its low-cost appeal, TAXF features an expense ratio of 29 basis points. Fixed income investors have been feasting on higher yields as the Federal Reserve has been tightening monetary policy to try to temper inflation.