<P> For a relatively small number of families, the child tax credit will exceed their tax liability . In many such cases, the unused portion of the child tax credit is refundable as the "additional child tax credit ." The amount that is available as a refund depends on the amount of earned income, and in certain circumstances the amount of social security and medicare taxes paid . Refer to IRS form 8812 and instructions . </P> <P> The child tax credit is available to taxpayers who have a "qualifying child". The full credit is only available if the family makes less than $110 K per year . A person is a "qualifying child" if he or she has not attained the age of 17 by the end of the taxable year and meets the requirements of 26 U.S.C. Sec. 152 (c). In general, a qualifying child is any individual for whom the taxpayer can claim a dependency exemption and who is the taxpayer's son or daughter (or descendent of either), stepson or stepdaughter (or descendent of either), or eligible foster child . </P> <P> The per - child amount was originally capped at $400 in 1998 (and $500 in 1999) by the Taxpayer Relief Act of 1997 . The Economic Growth and Tax Relief Reconciliation Act of 2001 (EGTRRA) set a graduated increase of the cap from $600 beginning in 2001 to $1,000 in 2010, but then reverting to $500 . The Jobs and Growth Tax Relief Reconciliation Act of 2003 (JGTRRA) increased the amount to $1,000 for 2003 and 2004 . The Working Families Tax Relief Act of 2004 extended this amount through 2010 . The Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010 extended this $1,000 cap through the end of 2012 . The American Taxpayer Relief Act of 2012 made the $1,000 cap permanent . </P> <P> A taxpayer's total tax credit is refundable to the extent of the greater of 15% of the taxpayer's earned income over $3,000 (new for 2009) (an amount adjusted for inflation IAW 26 U.S.C. Sec. 24 (d) (3)) or, as long as the taxpayer has three or more qualifying children, the excess of social security taxes paid over earned income credit, all subject to the income threshold . Unless a married couple files jointly, a qualifying child will be treated as such for the purpose of the Child Tax Credit for the taxpayer who is the child's parent, or if not a parent, the taxpayer with the highest adjusted gross income for the taxable year in accordance with 26 U.S.C. Sec. 152 (c) (4) (A). If more than one parent claims the child and do not file a joint return, the child will be treated as a qualifying child of the parent with whom the child resided for the longest period during the taxable year, and if the child resided with each parent equally, with the parent who has the highest adjusted gross income in accordance with 26 U.S.C. Sec. 152 (c) (4) (B). </P>

When was the additional child tax credit introduced