MUB — iShares National Muni Bond ETF
MUB is the largest municipal bond ETF, providing diversified exposure to thousands of investment-grade tax-exempt bonds issued by US state and local governments. Interest income from MUB is exempt from federal income taxes, making it particularly attractive to high-income investors in high tax brackets. MUB excludes bonds subject to the Alternative Minimum Tax (AMT), ensuring full federal tax exemption for most investors.
Top Holdings
Strategy
- →Use in taxable accounts for high-income investors whose marginal tax rate exceeds ~24%
- →Calculate the tax-equivalent yield to compare with taxable bonds on an after-tax basis
- →Diversify across state-specific muni funds with a core national allocation in MUB
- →Hold in taxable accounts — holding munis in an IRA wastes the tax exemption
Best For
- ✓High-income investors in the 32%+ federal tax bracket who benefit most from tax-exempt income
- ✓Retirees in high-tax states seeking tax-efficient income from municipal bonds
- ✓Taxable account investors who want fixed-income income without federal income tax on interest
- ✓Investors in states with no income tax who still value federal tax exemption
Key Risks
- ⚠Lower pre-tax yield than comparable taxable bonds — tax benefit only valuable in high brackets
- ⚠State and local government credit risk — though investment-grade municipal defaults are historically rare
- ⚠Interest rate sensitivity similar to other intermediate-duration bond ETFs
- ⚠AMT-excluded bonds may still have state-level tax obligations
Similar ETFs
Frequently Asked Questions
Are municipal bonds always tax-exempt?
MUB's interest income is exempt from federal income tax. However, it may be subject to state and local taxes depending on your state of residence and the issuing state of the bonds. MUB excludes AMT bonds for broader investor applicability. This is educational content, not financial advice.
What is the tax-equivalent yield?
The tax-equivalent yield converts a muni bond's tax-exempt yield to what a taxable bond would need to yield to match it after taxes. Formula: Tax-Equivalent Yield = Muni Yield / (1 - Tax Rate). For a 35% bracket investor, a 3% muni yield is equivalent to a 4.62% taxable yield. This is educational content, not financial advice.
Should I hold MUB in an IRA?
Generally no. Holding tax-exempt bonds in an already tax-advantaged IRA wastes the tax benefit since IRA distributions are taxed as ordinary income regardless. MUB's value is maximized in taxable brokerage accounts. This is educational content, not financial advice.
How safe are municipal bonds?
Investment-grade municipal bonds have historically very low default rates compared to corporate bonds at similar ratings. However, they are not risk-free — notable defaults have occurred in Detroit and Puerto Rico. MUB's diversification across thousands of issuers reduces individual default risk. This is educational content, not financial advice.
What is MUB's expense ratio?
MUB charges 0.05% annually, making it one of the most cost-efficient ways to access the national municipal bond market. This is educational content, not financial advice.
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