Social Security Tax Torpedo Calculator
Example: Annual Social Security benefit: 24000 $ · Other retirement income (IRA withdrawals, pension, dividends): 30000 $ · Filing status (0 = Single, 1 = Married Filing Jointly): 0
| Your effective marginal rate on next $1,000 of income | 22.20% |
| Percentage of SS benefit currently taxable | 47.08% |
| Taxable portion of SS benefit | $11,300 |
| Tax cost of adding $1,000 more income | $222 |
Worked example
A single retiree with $24,000 in Social Security and $30,000 in IRA withdrawals: combined income = $30,000 + $12,000 (half of SS) = $42,000, well above the $34,000 upper threshold. Up to 85% of SS becomes taxable. Adding $1,000 more in IRA withdrawals makes $850 more of SS taxable on top of the $1,000 — so the total taxable income rises by $1,850. At a 22% bracket rate, the effective marginal rate is 22% × 1.85 = 40.7% on that extra $1,000.
Frequently asked questions
How can I avoid the SS tax torpedo?
The torpedo hits hardest in the income zone between the lower and upper SS taxation thresholds. Strategies include: doing Roth conversions before collecting SS to reduce future RMD income; timing IRA withdrawals to manage combined income; delaying SS to maximize the benefit while living off lower-taxed sources; and using qualified charitable distributions (QCDs) from IRAs after age 70½ to reduce AGI without triggering SS taxation.
Do Roth withdrawals count toward combined income?
No. Roth IRA distributions are not included in AGI and do not count toward the combined income formula for SS taxation. This is one of the most powerful reasons to have Roth money in retirement — it provides income without triggering SS taxation or Medicare IRMAA surcharges.
Is this a federal-only effect?
Yes. The Social Security taxation rules are federal. Most states do not tax SS benefits at all. Thirteen states tax SS to varying degrees — check your state's rules, but the torpedo effect described here is purely federal.