The IRS website provides information about the poverty level and how it relates to a person's ability to receive the premium tax credit. However, the IRS website's figures are from 2013. Other websites like Families USA and Obamacare Facts provide updated poverty level figures for years after 2013.
According to the IRS website's Questions and Answers on the Premium Tax Credit page, the federal poverty level in 2013 was $11,490 for an individual, $15,510 for a family of two and $23,550 for a family of four. Households making between 100 and 400 percent of this value may be eligible for the premium tax credit.
The Families USA website provides a table with the 2015 federal poverty guidelines. The 2015 poverty level for an individual is $11,770, $15,930 for a family of two, and $24,250 for a family of four. The table lists the poverty levels for households between one and eight individuals. This website also lists the federal poverty guidelines for 2014, in case they are needed for historical reference.
The Obamacare Facts website describes how someone's income relative to the federal poverty level may help qualify for cost assistance when buying health insurance through the Health Insurance Marketplace. Families with income below 400 percent of the federal poverty level may be eligible for subsidies on health care, and family income below 250 percent of the federal poverty level may qualify families for reduced deductibles, copayments and maximum out-of-pocket costs.