AGI for determining if social security is taxed

The AGI is not the determining factor on whether or not the SS benefits are taxable.

Up to 85% of Social Security Retirement/Disability/Survivors benefits becomes taxable when all your other income plus 1/2 your social security reaches:

• Married Filing Jointly - $32,000
• Single or Head of Household - $25,000
• Married Filing Separately - 0

No. The following income is used to determine the amount of taxable social security income.

The maximum amount of social security benefits that can be added to your tax return is 85% of your total benefits.

• if half of your social security, combined with your other taxable income and any tax exempt interest is below the following base amounts, then none of your social security would count as taxable income.
• The base amount for your filing status is:
  • $25,000 if you're single, head of household, or qualifying surviving spouse,
  • $25,000 if you're married filing separately and lived apart from your spouse for the entire year,
  • $32,000 if you're married filing jointly,
  • $0 if you're married filing separately and lived with your spouse at any time during the tax year. 
• Social Security Income FAQs
• IRS Publication 915 (page 16, Worksheet)

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