In the case of an individual described in subsection (a) who is determined by a qualified entity to be presumptively eligible for medical assistance under a State plan, the individual shall apply for medical assistance under such plan by not later than the last day of the month following the month during which the determination is made.
42 U.S. Code § 1396r–1b. Presumptive eligibility for certain breast or cervical cancer patients
Section applicable to medical assistance for items and services furnished on or after Oct. 1, 2000, without regard to whether final regulations to carry out such amendments have been promulgated by such date, see section 2(d) of Pub. L. 106–354, set out as an Effective Date of 2000 Amendment note under section 1396a of this title.
 So in original. Probably should be “an”.