After-Tax Yield
After-Tax Yield
Your tax bill is the difference between the yield your broker reports and the yield you can spend. Know your tax bracket.
Key takeaways
- After-tax yield = nominal yield × (1 − marginal tax rate)
- Most bond interest is taxed as ordinary income, not at capital-gains rates
- Tax brackets vary by filing status and income; know yours
- State and local taxes can add 3–13% to federal taxes on bond interest
- Tax-exempt municipal bonds are valuable only if your tax bracket is high enough to justify their lower yields
Why taxes matter for bonds
A stock investor might say, "I hold for 20 years and defer all taxes." A bond investor lives with coupons arriving every six months, triggering tax liability even if you reinvest them. This is a major structural difference.
Example: You hold $100,000 in bond funds yielding 4%. You receive $4,000 in interest annually. At a 37% federal marginal tax rate (including the 3.8% Net Investment Income Tax for high earners), you owe roughly $1,520 in federal tax on that $4,000. Your after-tax income is $2,480 — a 2.48% after-tax yield, not 4%.
This isn't optional. If the bonds are in a taxable account, the tax is due.
Computing after-tax yield
The formula is simple:
After-tax yield = nominal yield × (1 − marginal tax rate)
Example:
- Nominal yield: 5.0%
- Your marginal tax rate: 32% (federal + NIIT)
- After-tax yield: 5.0% × (1 − 0.32) = 3.4%
The same bond that seemed attractive at 5% is less so at 3.4% after-tax.
Federal tax brackets on ordinary income (2025)
For bonds held in taxable accounts, the interest is taxed as ordinary income at your marginal rate. In 2025, the federal brackets for single filers are (approximately):
- 10% on income up to $11,000
- 12% on income from $11,001 to $44,725
- 22% on income from $44,726 to $95,375
- 24% on income from $95,376 to $182,100
- 32% on income from $182,101 to $231,250
- 35% on income from $231,251 to $578,125
- 37% on income over $578,125
Plus, if your Modified Adjusted Gross Income (MAGI) exceeds certain thresholds (about $200,000 for single filers in 2025), you pay an additional 3.8% Net Investment Income Tax (NIIT) on net investment income, including bond interest.
So a high-income investor might have an all-in federal marginal rate of 37% + 3.8% = 40.8%.
State and local taxes (SALT)
Many states tax bond interest as ordinary income. The rates vary:
- California: up to 13.3% (top rate).
- New York: up to 10.9%.
- Massachusetts: 5%.
- Florida, Texas, Wyoming: 0% (no state income tax).
Adding state tax to your federal rate is crucial:
Federal 32% + state 10% = 42% marginal tax rate on bond interest.
This is why retirees and high-income investors often consider moving to low-tax states (Florida, Nevada, Texas) — the state tax savings on portfolio income can be substantial.
The after-tax yield gap
Consider two scenarios:
Investor A (low bracket, no state tax):
- Yield: 4.5%
- Federal + NIIT: 22%
- State: 0%
- After-tax yield: 4.5% × (1 − 0.22) = 3.51%
Investor B (high bracket, high-tax state):
- Yield: 4.5%
- Federal + NIIT: 40.8%
- State: 10%
- After-tax yield: 4.5% × (1 − 0.508) = 2.21%
Same bond, same 4.5% nominal yield. Investor A keeps 3.51% after-tax; Investor B keeps 2.21%. That's a massive difference, driven entirely by tax brackets and geography.
This is why tax-efficient investing is not a luxury — it's a core component of returns for taxable accounts.
Tax-exempt municipal bonds
Municipal bonds (issued by states and municipalities) typically pay interest that is exempt from federal tax, and often from state and local tax if you live in the issuing state.
Example: A municipal bond yields 3.5% (tax-free) in New York. An equivalent corporate bond yields 5% (taxable).
For Investor B above (42% marginal rate), the after-tax corporate yield is 5% × (1 − 0.42) = 2.9%.
The municipal bond at 3.5% tax-free beats the corporate bond's 2.9% after-tax return. So you accept a lower nominal yield in exchange for tax exemption.
But for Investor A (22% marginal rate), the corporate bond's after-tax return is 5% × (1 − 0.22) = 3.9%, which beats the municipal's 3.5%. For lower-bracket investors, munis often don't make sense.
The break-even formula:
Tax-free yield needed = taxable yield × (1 − marginal rate)
If a taxable bond yields 5% and your marginal rate is 35%, you need a 3.25% tax-free yield to break even. Shop for munis only if they yield above that threshold.
Capital gains and losses on bonds
When you sell a bond at a gain or loss, the difference between sale price and cost basis is a capital gain or loss. Long-term capital gains (held >1 year) are taxed at preferential rates — typically 15% or 20% for high earners.
Example: You buy a bond at $950 (cost basis). You sell it at $1,020 one year later. The $70 gain is a long-term capital gain, taxed at 15% or 20%, not ordinary income rates. You owe roughly $10.50–$14 in federal tax, not $22.40 (which you'd owe if taxed as ordinary income).
This is an argument for holding bonds to maturity in taxable accounts: you avoid the capital-gains tax on price appreciation and receive ordinary income treatment only on coupons (which you'd owe anyway). Active traders, by contrast, incur frequent capital-gains taxes.
Original Issue Discount (OID) and phantom income
When you buy a bond issued below par (with Original Issue Discount), the tax treatment is complex. You must accrue the discount annually as phantom income, even if you don't receive cash until maturity. This is covered later; for now, understand that OID bonds create a tax liability before you sell or receive principal.
Tax-loss harvesting in bond funds
Bond prices fall when rates rise. If you own individual bonds in a taxable account and sell one at a loss, you can harvest that loss to offset capital gains elsewhere (or up to $3,000 of ordinary income per year).
Example: You own a bond fund that lost $5,000 in value as rates rose. You sell it, realizing a $5,000 loss. You offset $5,000 of gains from a stock sale elsewhere in your portfolio. The wash-sale rule (holding restrictions on substantially identical securities) applies for 30 days, so you can't immediately rebuy the same bond fund, but the tax deferral is real.
Tax-loss harvesting is a free lunch for taxable accounts and shouldn't be ignored.
The decision tree for bond account placement
Practical example: building a taxable portfolio
Suppose you have $500,000 to invest:
- $200,000 in a Roth IRA: buy a high-yield bond fund (BND, AGG) — the tax-free growth is invaluable.
- $150,000 in a taxable brokerage: buy a municipal bond fund (MUB) for your taxable account — the tax-exempt yield beats taxable bonds after-tax for your bracket.
- $150,000 in taxable: buy stocks (index funds, dividend-focused ETFs) — long-term capital gains are taxed more favorably than bond interest.
This allocation optimizes for tax drag. By placing high-coupon bonds in tax-sheltered accounts and tax-free munis in taxable accounts, you minimize what the IRS takes.
Common mistake: ignoring state taxes
Many investors focus on federal taxes and forget state and local. If you live in a high-tax state (California, New York, New Jersey), state taxes on bonds can rival federal taxes. An after-tax bond yield calculation that ignores state tax is incomplete.
If moving to a low-tax state is realistic, the ongoing tax savings on bond interest (and dividends, and capital gains) can more than offset moving costs over a decade.
Summary: the yield you actually keep
Brokers report pre-tax yields. Economists publish real (inflation-adjusted) yields. But the yield that matters for your retirement spending is the after-tax yield. Know your marginal tax rate, factor in state and local taxes, and run the after-tax calculation on every bond or bond fund you consider for a taxable account.
Tax-advantaged accounts (Roth, 401k, HSA) make this irrelevant — a huge advantage of those accounts. For taxable money, after-tax yield should be the deciding metric between taxable bonds and tax-exempt munis.
Related concepts
Next
We've subtracted inflation and taxes from nominal yield. Now we add back the extra yield that compensates for credit risk and other factors beyond interest-rate moves — the yield spread, and what it tells you about a bond's value.