((a)) ** First offense** Except as provided in , any person at least eighteen years of age who violates by distributing a controlled substance to a person under twenty-one years of age is (except as provided in subsection (b)) subject to (1) twice the maximum punishment authorized by , and (2) at least twice any term of supervised release authorized by , for a first offense involving the same controlled substance and schedule. Except to the extent a greater minimum sentence is otherwise provided by , a term of imprisonment under this subsection shall be not less than one year. The mandatory minimum sentencing provisions of this subsection shall not apply to offenses involving 5 grams or less of marihuana.section 860 of this titlesection 841(a)(1) of this titlesection 841(b) of this titlesection 841(b) of this titlesection 841(b) of this title

((b)) ** Second offense** Except as provided in , any person at least eighteen years of age who violates by distributing a controlled substance to a person under twenty-one years of age after a prior conviction under subsection (a) of this section (or under as in effect prior to ) has become final, is subject to (1) three times the maximum punishment authorized by , and (2) at least three times any term of supervised release authorized by , for a second or subsequent offense involving the same controlled substance and schedule. Except to the extent a greater minimum sentence is otherwise provided by , a term of imprisonment under this subsection shall be not less than one year. Penalties for third and subsequent convictions shall be governed by .section 860 of this titlesection 841(a)(1) of this titlesection 333(b) of this titlesection 841(b) of this titlesection 841(b) of this titlesection 841(b) of this titlesection 841(b)(1)(A) of this titleMay 1, 19711971-05-01