(a) For each taxable year beginning on or after January 1, 2007, the tax credit authorized by section twenty-two of this article may be used by every qualified taxpayer and shall be calculated in accordance with subsections (b) and (c) of this section: Provided, That for the taxable year beginning on January 1, 2007, the qualified taxpayer shall be allowed to claim only fifty percent of the amount of the tax credit.

(b) Qualified taxpayers who file as an individual, as a head of household, as a husband and wife who file a joint return, or as an individual entitled to file as a surviving spouse shall be entitled to a tax credit based on the following:

(1) If modified federal adjusted gross income is at or below the federal poverty guidelines based on family size, the credit shall be an amount equal to the amount of tax owed under this article by the qualified taxpayer;

(2) If modified federal adjusted gross income is greater than the federal poverty guidelines but does not exceed $300 above the federal poverty guidelines based on family size, the amount of credit allowable shall be ninety percent of the amount of tax owed under this article by the qualified taxpayer;

(3) If modified federal adjusted gross income is greater than $300 above the federal poverty guidelines but does not exceed $600 above the federal poverty guidelines based on family size, the amount of credit allowable shall be eighty percent of the amount of tax owed under this article by the qualified taxpayer;

(4) If modified federal adjusted gross income is greater than $600 above the federal poverty guidelines but does not exceed $900 above the federal poverty guidelines based on family size, the amount of credit allowable shall be seventy percent of the amount of tax owed under this article by the qualified taxpayer;

(5) If modified federal adjusted gross income is greater than $900 above the federal poverty guidelines but does not exceed $1,200 above the federal poverty guidelines based on family size, the amount of credit allowable shall be sixty percent of the amount of tax owed under this article by the qualified taxpayer;

(6) If modified federal adjusted gross income is greater than $1,200 above the federal poverty guidelines but does not exceed $1,500 above the federal poverty guidelines based on family size, the amount of credit allowable shall be fifty percent of the amount of tax owed under this article by the qualified taxpayer;

(7) If modified federal adjusted gross income is greater than $1,500 above the federal poverty guidelines but does not exceed $1,800 above the federal poverty guidelines based on family size, the amount of credit allowable shall be forty percent of the amount of tax owed under this article by the qualified taxpayer;

(8) If modified federal adjusted gross income is greater than $1,800 above the federal poverty guidelines but does not exceed $2,100 above the federal poverty guidelines based on family size, the amount of credit allowable shall be thirty percent of the amount of tax owed under this article by the qualified taxpayer;

(9) If modified federal adjusted gross income is greater than $2,100 above the federal poverty guidelines but does not exceed $2,400 above the federal poverty guidelines based on family size, the amount of credit allowable shall be twenty percent of the amount of tax owed under this article by the qualified taxpayer; or

(10) If modified federal adjusted gross income is greater than $2,400 above the federal poverty guidelines but does not exceed $2,700 above the federal poverty guidelines based on family size, the amount of credit allowable shall be ten percent of the amount of tax owed under this article by the qualified taxpayer.

(c) Qualified taxpayers who are husband and wife and who file separate returns shall be entitled to a tax credit based on the following:

(1) If modified federal adjusted gross income is at or below fifty percent of the federal poverty guidelines based on family size, the credit shall be an amount equal to the amount of tax owed under this article by the qualified taxpayer;

(2) If modified federal adjusted gross income is greater than fifty percent of the federal poverty guidelines but does not exceed $150 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be ninety percent of the amount of tax owed under this article by the qualified taxpayer;

(3) If modified federal adjusted gross income is greater than $150 above fifty percent of the federal poverty guidelines but does not exceed $300 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be eighty percent of the amount of tax owed under this article by the qualified taxpayer; (4) If modified federal adjusted gross income is greater than $300 above fifty percent of the federal poverty guidelines but does not exceed $450 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be seventy percent of the amount of tax owed under this article by the qualified taxpayer;

(5) If modified federal adjusted gross income is greater than $450 above fifty percent of the federal poverty guidelines but does not exceed $600 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be sixty percent of the amount of tax owed under this article by the qualified taxpayer;

(6) If modified federal adjusted gross income is greater than $600 above fifty percent of the federal poverty guidelines but does not exceed $750 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be fifty percent of the amount of tax owed under this article by the qualified taxpayer;

(7) If modified federal adjusted gross income is greater than $750 above fifty percent of the federal poverty guidelines but does not exceed $900 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be forty percent of the amount of tax owed under this article by the qualified taxpayer;

(8) If modified federal adjusted gross income is greater than $900 above fifty percent of the federal poverty guidelines but does not exceed $1,050 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be thirty percent of the amount of tax owed under this article by the qualified taxpayer;

(9) If modified federal adjusted gross income is greater than $1,050 above fifty percent of the federal poverty guidelines but does not exceed $1,200 above fifty percent of the federal poverty guidelines based on family size, the amount of credit allowable shall be twenty percent of the amount of tax owed under this article by the qualified taxpayer; or

(10) If modified federal adjusted gross income is greater than $1,200 above fifty percent of the federal poverty guidelines but does not exceed $1,350 above fifty percent of the federal poverty guidelines based on family size, the amount of credit shall be ten percent of the amount of tax owed under this article by the qualified taxpayer.

(d) The Tax Commissioner shall develop and publish on an annual basis two indexed tax credit tables. One tax table shall be for qualified taxpayers who file as an individual, as a head of household, as a husband and wife who file a joint return, or as an individual entitled to file as a surviving spouse and one tax table shall be for qualified taxpayers who are husband and wife and who file separate returns. The indexed tax credit tables shall be based on subsections (b) and (c) of this section.