iShares National Muni Bond ETF (MUB): Complete Beginner's Guide
Last updated: March 2026 • BlackRock • Municipal Bond
Expense Ratio
0.07%
AUM
$35.0B
Dividend Yield
3.20%
Inception
2007
Beginner Score
10/10
What is iShares National Muni Bond ETF?
MUB invests in investment-grade municipal bonds issued by U.S. state and local governments, which are exempt from federal income tax. This tax advantage makes munis particularly attractive for investors in higher tax brackets. Beginners should understand that MUB's stated yield understates its true benefit because the income is tax-free at the federal level, effectively boosting your after-tax return.
MUB is managed by BlackRock and has been available since 2007. With $35.0B in assets under management, it's a well-established fund with strong institutional backing. The fund charges an expense ratio of 0.07%, which means for every $10,000 you invest, you pay approximately $7 per year in management fees.
MUB at a Glance — Key Metrics
| Expense Ratio | 0.07% |
| Total Holdings | 5,600 |
| P/E Ratio | N/A |
| Beta | 0.12 |
| Dividend Yield | 3.20% |
| AUM | $35.0B |
| Inception Year | 2007 |
| Issuer | BlackRock |
Top 10 Holdings in MUB
MUB holds 5,600 different securities. Here are the largest positions that make up the core of this fund:
| # | Company | Ticker | Weight |
|---|---|---|---|
| 1 | California State GO 5.0% 2038 | N/A | 0.80% |
| 2 | New York City GO 5.0% 2035 | N/A | 0.70% |
| 3 | Texas State Transportation 4.5% 2040 | N/A | 0.60% |
| 4 | Massachusetts State GO 4.0% 2037 | N/A | 0.50% |
| 5 | New Jersey Turnpike Auth 5.0% 2042 | N/A | 0.50% |
| 6 | Illinois State GO 5.25% 2033 | N/A | 0.50% |
| 7 | Florida Board of Education 4.5% 2036 | N/A | 0.40% |
| 8 | Washington State GO 4.25% 2038 | N/A | 0.40% |
| 9 | Pennsylvania Turnpike 5.0% 2041 | N/A | 0.40% |
| 10 | Georgia State GO 4.0% 2034 | N/A | 0.30% |
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MUB Performance History
Here's how MUB has performed over different time periods. Remember that past performance doesn't guarantee future results, but it gives you a sense of the fund's track record:
YTD
0.50%
1 Year
2.80%
3 Year
-0.20%
5 Year
1.20%
10 Year
2.20%
Beginner Suitability Score: 10/10
Our proprietary Beginner Suitability Score evaluates ETFs based on five factors that matter most to new investors: fees, volatility, diversification, dividend history, and track record length.
MUB scores 10/10 because it has very low fees, shows lower-than-average volatility, offers broad diversification across 5,600 holdings, and has been available since 2007, giving it a proven track record.
How to Buy MUB — Step by Step
- Open a brokerage account — We recommend Fidelity, Charles Schwab, or Vanguard for ETF investing. All offer $0 commissions on ETF trades.
- Fund your account — Transfer money from your bank. You can start with as little as $1 if your broker offers fractional shares.
- Search for "MUB" — Use the search bar in your brokerage platform to find iShares National Muni Bond ETF.
- Place your order — Choose "Market Order" for simplicity or "Limit Order" if you want to set a specific price. Enter how many shares (or dollar amount) you want to buy.
- Set up automatic investing — Most brokers let you schedule recurring purchases (e.g., $100/month on the 1st). This is dollar cost averaging in action.
Dollar Cost Averaging Into MUB
Here's what consistent monthly investing could look like over time, assuming an average annual return of 8% (approximate historical stock market average):
| Monthly | 10 Years | 20 Years | 30 Years |
|---|---|---|---|
| $100/mo | $18,417 | $59,295 | $150,030 |
| $250/mo | $46,041 | $148,237 | $375,074 |
| $500/mo | $92,083 | $296,474 | $750,148 |
*Projections assume 8% average annual return with monthly compounding. Actual returns will vary. Past performance doesn't guarantee future results.
Fee impact: With MUB's expense ratio of 0.07%, a $10,000 investment would lose approximately $600 to fees over 20 years compared to a zero-fee investment. This is a reasonable fee level for the value provided.
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Pros and Cons of MUB
Pros
- ✓Federal tax-exempt income significantly boosts after-tax returns for investors in higher brackets
- ✓Extremely broad diversification across over 5,600 municipal bonds from all 50 states
- ✓Very low expense ratio of 0.07% makes it the cheapest way to access the muni bond market
- ✓Low volatility and low correlation with stocks make it excellent for portfolio stability
Cons
- ✗Lower pre-tax yield than taxable bonds, so the tax benefit only helps investors in higher brackets
- ✗Interest rate sensitivity can still cause price declines when rates rise
- ✗Municipal credit risk exists, though defaults are historically very rare for investment-grade munis
MUB vs Similar ETFs
See how MUB stacks up against similar funds:
Frequently Asked Questions
Is MUB a good ETF for beginners?▾
MUB has a Beginner Suitability Score of 10/10 on our scale. This makes it a strong choice for new investors due to its low fees and broad diversification.
What is the expense ratio of MUB?▾
MUB has an expense ratio of 0.07%. This means for every $10,000 you invest, you pay approximately $7 per year in fees. This is considered very low and cost-efficient.
How much money do I need to invest in MUB?▾
You can invest in MUB with as little as $1 through brokers that offer fractional shares (like Fidelity, Schwab, or Robinhood). There is no minimum investment required beyond the share price itself, which changes daily. Dollar cost averaging — investing a fixed amount regularly — is a popular strategy.
Does MUB pay dividends?▾
Yes, MUB pays dividends with a current yield of approximately 3.20%. Dividends are typically paid quarterly and can be reinvested automatically through most brokers.
What are the top holdings in MUB?▾
The top holdings in MUB include California State GO 5.0% 2038 (0.80%), New York City GO 5.0% 2035 (0.70%), Texas State Transportation 4.5% 2040 (0.60%), and more. The fund holds 5,600 total positions, providing broad diversification across many companies.