Tax expenditure refers to the financial support provided through the tax code, including tax reduction or exemption, non-taxation, income deduction, tax credit, application of favored-tax rates or deferral of tax. And, aimed at providing assistance to specific groups and fields, tax expenditures with the same policy goals as direct expenditures are being expanded as separate policies. However, concerns have been raised over the effectiveness of such programs as each program is managed by different ministries under different regulations. Accordingly, this study interconnects and examines Korea’s rapidly expanding tax and direct expenditures for low income support. Based on a four-member, single-earner household, a comparative analysis was conducted on households with annual earned incomes of between 9 million and 12 million won and 12 million and 15.5 million won. Both groups receive basic living security, through direct expenditures for livelihood and housing benefits. And, in line with increases in the earned income, they are also provided with earned income tax credits, which are a form of tax expenditure aimed at encouraging the labor supply and support incomes for the working poor. It should be noted here that, the livelihood benefit and EITC are reduced as earned income rises, which in turn, creates an income reversal, which refers to a loss in the total post-tax income.