Municipal Bonds First and foremost, muni bond income remains tax-free at the Federal level for individual investors, as it has been since the Federal personal income tax was established in 1913. Personal income tax rates though were adjusted modestly by the tax act, including a reduction in the highest marginal rate from 39.6% to 37%. From a technical perspective, this should have minimal effect on demand from individual investors who own almost two-thirds of the market. The corporate tax rate reduction (from 35% to 21%), however, increases the attractiveness of taxable bonds relative to tax-advantaged securities for most corporations. This includes banks, credit unions and P&C companies which combined, comprise one-quarter of the market. Conversely, proration rules for life insurance companies were modified, thus increasing the attractiveness of tax-exempts relative to taxables for this historically small segment of the muni market.