Additional amount
4 rules
In the case of a taxpayer with respect to whom the amount determined under subsection (b)(1)(A) exceeds the adjusted base amount, the amount included in gross income under this section shall be equal to the lesser of—
(A) the sum of— (i) 85 percent of such excess, plus (ii) the lesser of the amount determined under paragraph (1) or an amount equal to one-half of the difference between the adjusted base amount and the base amount of the taxpayer, or
(B) 85 percent of the social security benefits received during the taxable year.