1. Short title This Act may be cited as the CHIP Stability Act . 2. CHIP allocation redistribution special rule for certain shortfall States during first quarter of fiscal year 2018 Section 2104(f)(2) of the Social Security Act ( 42 U.S.C. 1397dd(f)(2) ) is amended— (1) by amending subparagraph (B) to read as follows: (B) Determination of redistributed amounts if insufficient amounts available (i) Proration rule Subject to clause (ii), if the amounts available for redistribution under paragraph (1) for a fiscal year are less than the total amounts of the estimated shortfalls determined for the year under subparagraph (A), the amount to be redistributed under such paragraph for each shortfall State shall be reduced proportionally. (ii) Special rule for first quarter of fiscal year 2018 (I) In general For the period beginning on October 1, 2017, and ending December 31, 2017, with respect to any amounts available for redistribution under paragraph (1) for fiscal year 2018, the Secretary shall redistribute under such paragraph such amounts to each emergency shortfall State (as defined in subclause (II)) in such amount as is equal to the amount of the shortfall described in subclause (II) for such State and period (as may be adjusted under subparagraph (C)) before the Secretary may redistribute such amounts to any shortfall State that is not an emergency shortfall State. In the case of any amounts redistributed under this subclause to a State that is not an emergency shortfall State, such amounts shall be determined in accordance with clause (i). (II) Emergency shortfall State defined For purposes of this clause, the term emergency shortfall State means, with respect to the period beginning October 1, 2017, and ending December 31, 2017, a shortfall State for which the Secretary estimates, in accordance with subparagraph (A) (unless otherwise specified in this subclause), that the projected expenditures under the State child health plan and under section 2105(g) (calculated as if the reference under section