Irc section 199 July 8, 2019 16 32 64 128 Irc section 199a Irc section 199a deduction Irc section 199a specified service business Irc section 199 deduction Irc section 199a dividends Irc section 199a adjustment Irc section 199a phase out Irc section 199a g Irc section 199a(b)(1)(b) Section 199a explained