After you file

Social Security can  be up to 85% taxable depending on your filing status and other income.  This means if you had social security benefits of $30,000 and you are married filing separately $25,500 would be included in your taxable income.  If you are not having taxes withheld from that, then you would owe taxes at the end of the year as social security does not automatically withhold taxes based on your payment amount like an employer does.  

If your situation will similar next year, then you can either make estimated payments or you can request from Social Security that they withhold taxes from your benefits. 

Taxability of Social Security Benefits

• General Rule: Social Security benefits are not fully taxed. Depending on your "combined income," up to 85% of your benefits may be taxable.
• SSDI Treatment: SSDI (Social Security Disability Insurance) benefits are treated exactly the same as regular Social Security benefits for tax purposes.
• Thresholds for 85% Taxable:
  • Single: Combined income above $34,000.
  • Married Filing Jointly: Combined income above $44,000.
  • Married Filing Separate: Benefits are taxable at 85% regardless of income level.
• Thresholds for 50% Taxable:
  • Single: Combined income between $25,000 and $34,000.
  • Married Filing Jointly: Combined income between $32,000 and $44,000.
• Calculation Formula: "Combined Income" is calculated as your Adjusted Gross Income (AGI) + Nontaxable Interest + 1/2 of your Social Security Benefits.