How old are you?  

There are 2 different things to know about social security. People get them mixed up all the time.

1. Your actual SS checks

If you are over full retirement age your actual ss checks won't be reduced. Otherwise they will actually reduce your payments if you make too much other income in the prior year.  See SS FAQ for working after retirement

https://www.ssa.gov/planners/retire/whileworking.html

2. Income Tax

For any age up to 85% of Social Security 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

3. If you have earned income after retirement, you still pay social security tax on your wages, even though you are also receiving benefits.  However, your new earnings go into the system and may result in a recalculation that increases your benefit, depending on your prior work history.

Generally speaking, it works like this. Your total income is subject to INCOME tax and this includes your self-employment income...the $10,000 you mentioned. Your SS income is partially taxable once your income exceeds $25k, based on your total income from all sources.

Additionally, your self-employment NET income is also subject to 15.3% social security tax. Net income is your gross income ($10,000) less your business expenses. So keep track of those business expenses and they will help you reduce your total taxes.

Good luck to you.

Kelly C, CPA