Social Security benefits may be tax free or includible in gross income at 50% or 85%. This depends on a couple’s income, Social Security benefits, and tax-exempt interest. The fact that the benefits are payable to a third party does not change the tax result; the Social Security checks are being used for the taxpayer’s benefit.
Generally, an unmarried person who maintains a household for dependents and is allowed to compute his or her tax based on head of household rates, which are more favorable than single person rates.