Supplemental Security Income payments are based on countable income, not on hours worked. Countable income is directly deducted from SSI payments. Earned income is considered countable income at a rate of half the earned income after the first $65.
For the year 2015, Federal SSI payments are calculated as $733 per month less countable income. SSI may be reduced without any earned income because countable income includes income from sources such as veterans benefits and monetary support from others. Any earnings beyond $65 lower SSI payments. If the recipient has no unearned income, excluded earnings are raised to $85. Earnings between $1,531 and $1,551 per month reduce SSI benefits to zero.