California · Margin Interest Deduction
Margin Interest Deduction in California (2026)
Deduct interest paid on margin loans used to purchase taxable investments, limited to your net investment income for the year. California has a progressive income tax with a top rate of 13.3%, so a California filer's combined marginal rate on the next dollar at $91,905 of income is about 31.3% (22% federal + 9.3% CA).
2026 savings example for California
Planning estimate for a single filer earning $91,905 (California median household income in LevyIO's state dataset) who removes $5,000 from taxable income. Federal tax uses the 2026 IRS brackets after the $16,100 standard deduction; CA tax uses the state brackets in LevyIO's dataset and assumes the state follows the federal treatment.
Estimated total savings
$1,565
Federal savings
$1,100
$11,389 → $10,289 · 22% bracket
CA state savings
$465
$4,455 → $3,990 · 9.3% marginal
Combined marginal rate
31.3%
≈ $313 saved per $1,000 deducted
Federal × California marginal rates (2026, single)
Gross-income ranges include the federal standard deduction. The CA column is the state marginal rate at the midpoint of each range. The last column is the tax saved per $1,000 deducted at that combined rate.
| Federal bracket | Gross income (single) | CA marginal | Combined | Per $1,000 |
|---|---|---|---|---|
| 10% | $16,100 - $28,500 | 2% | 12% | $120 |
| 12% | $28,500 - $66,500 | 6% | 18% | $180 |
| 22% | $66,500 - $121,800 | 9.3% | 31.3% | $313 |
| 24% | $121,800 - $217,875 | 9.3% | 33.3% | $333 |
| 32% | $217,875 - $272,325 | 9.3% | 41.3% | $413 |
| 35% | $272,325 - $656,700 | 11.3% | 46.3% | $463 |
| 37% | Over $656,700 | 11.3% | 48.3% | $483 |
Eligibility & forms
Investors who borrow on margin to purchase taxable investments
- Must itemize deductions
- Limited to net investment income
- Cannot use for tax-exempt investments
- Excess carries forward to future years
Federal forms: Form 4952, Schedule A
California filing notes
Maximize tax-deferred contributions. Plan for the additional 1% surcharge over $1M. If leaving California, document your move thoroughly. The FTB aggressively audits departing high-income residents.
Common mistakes: Deducting margin interest for tax-exempt bond purchases; Not tracking carryforward of excess interest; Forgetting to elect to treat capital gains as investment income.
Frequently asked questions
How much can the Margin Interest Deduction save a California taxpayer in 2026?
In LevyIO's example, a single filer with $91,905 of income (the California median household income in our state dataset) who removes $5,000 from taxable income saves about $1,100 in 2026 federal tax (22% marginal bracket) plus about $465 in California tax (9.3% state marginal rate), roughly $1,565 combined. It is a planning estimate computed from the 2026 IRS brackets and LevyIO's CA bracket data, not a survey figure.
What is the California income tax rate for 2026?
California has a progressive income tax with a top rate of 13.3%. The CA standard deduction in LevyIO's dataset is $5,706 single / $11,412 married. Highest state income tax (13.3%). Additional 1% Mental Health Services Tax over $1M. No preferential capital gains rate.
Who qualifies for the Margin Interest Deduction in California?
Investors who borrow on margin to purchase taxable investments. The federal rules are the same in every state; the requirements are: Must itemize deductions; Limited to net investment income; Cannot use for tax-exempt investments; Excess carries forward to future years. California filers should confirm on the CA return whether the state follows the federal treatment.
Which forms do I file to claim the Margin Interest Deduction?
Federal: Form 4952, Schedule A. California: check the California Franchise Tax Board instructions for the matching state schedule. Common mistakes: Deducting margin interest for tax-exempt bond purchases; Not tracking carryforward of excess interest; Forgetting to elect to treat capital gains as investment income.
Margin Interest Deduction in other states
Sources
Reviewed 2026-09-17. Estimates are educational planning figures computed from the IRS 2026 inflation adjustments and LevyIO's state bracket dataset; they are not tax advice.