iShares National Muni Bond ETF (MUB): Complete Beginner's Guide

iShares National Muni Bond ETF (MUB) is a municipal bond ETF from BlackRock with an expense ratio of 0.07% and $35.0B in assets under management. Our Beginner Suitability Score: 10/10 (Great for Beginners). 5-year annualized return: 1.20%.

Last updated: April 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%

MUB Top 10 Holdings

MUB's top holding is California State GO 5.0% 2038 (N/A) at 0.80%, followed by New York City GO 5.0% 2035 (N/A) at 0.70% and Texas State Transportation 4.5% 2040 (N/A) at 0.60%. The top 10 holdings account for 5.10% of the fund's 5,600 total positions.

See how MUB's holdings overlap with similar ETFs →

View data table

Rank	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%

Rank	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%

Want the full framework? This 2-hour ETF course teaches you exactly how to pick, buy, and hold profitable ETFs — from zero to confident investor. Under $15.

Ready to invest? Open an IBKR account in 10 minutes and get free stock. $0 commissions on US ETFs • Fractional shares from $1 • 150+ global markets.

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%

MUB Performance Returns

MUB has returned 1.20% annualized over 5 years and 2.20% over 10 years. YTD return is 0.50%.

Compare MUB with other ETFs →

View data table

Period	Return
YTD	0.50%
1 Year	2.80%
3 Year	-0.20%
5 Year	1.20%
10 Year	2.20%

Rank	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%

Beginner Suitability Score: 10/10

Great for Beginners

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.

MUB Sector Allocation

Here's how MUB distributes its investments across different sectors of the economy:

MUB Sector Allocation

MUB's largest sector allocation is State General Obligation at 22.5%, followed by Transportation Revenue at 16.8% and Water & Sewer Revenue at 13.2%.

View data table

Sector	Weight
State General Obligation	22.5%
Transportation Revenue	16.8%
Water & Sewer Revenue	13.2%
Education Revenue	11.5%
Hospital Revenue	9.2%
Electric Power Revenue	7.8%
Local General Obligation	8.5%
Housing Revenue	5.5%
Other Municipal	5.0%

Rank	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%

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.

MUB Fee Impact Over 20 Years

MUB's expense ratio of 0.07% costs $601 on a $10,000 investment over 20 years (assuming 8% annual return). Without fees, the investment would grow to $46,610 instead of $46,009.

Understand expense ratios →Calculate your returns →

View data table

Year	Without Fees	With Fees	Fee Cost
0	$10,000	$10,000	$0
5	$14,693	$14,646	$47
10	$21,589	$21,450	$139
15	$31,722	$31,415	$307
20	$46,610	$46,009	$601

Rank	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%

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:

MUB vs BNDCompare →

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.

What sectors does MUB invest in?▾

MUB's largest sector allocations are State General Obligation (22.50%), Transportation Revenue (16.80%), Water & Sewer Revenue (13.20%). This sector distribution shows a focus on state general obligation stocks.

How much do MUB's fees cost over time?▾

With an expense ratio of 0.07%, a $10,000 investment in MUB would lose approximately $600 to fees over 20 years (assuming 8% annual returns). This is a reasonable fee level.