Not everything an individual receives is considered to be income. Generally, if the item received cannot be used as, or to obtain, food or shelter, it will not be considered as income. For example, if someone pays an individual's medical bills, or offers free medical care, or if the individual receives money from a social services agency that is a repayment of an amount he/she previously spent, that value is not considered income to the individual. In addition, some items that are considered to be income are excluded when determining the amount of an individual's benefit.
Principal earned income exclusions
Principal unearned income exclusions
General earned income exclusion
For 2013, if an individual has only earnings income, then he or she could earn up to $1,505 per month and still be eligible for an SSI benefit. However, if an individual has monthly earnings of $1040 or more in 2013, then the person would be considered to be engaging in substantial gainful activity and would probably not be eligible for SSI disability benefits (unless he or she is blind).