Amendment by Pub. L. 99–509, except as otherwise provided, effective with respect to payments due with respect to wages paid after Dec. 31, 1986, including wages paid after such date by a State (or political subdivision thereof) that modified its agreement pursuant to section 418(e)(2) of Title 42, The Public Health and Welfare, see section 9002(d) of Pub. L. 99–509, set out as a note under section 418 of Title 42.