45 CFR §156.260

1. (a)Individual market requirement. A QHP issuer must:
   1. (1)Enroll a qualified individual during the initial and annual open enrollment periods described in § 155.410(b) and (e) of this subchapter, and abide by the effective dates of coverage established by the Exchange in accordance with § 155.410(c) and (f) of this subchapter; and
   2. (2)Make available, at a minimum, special enrollment periods described in § 155.420(d) of this subchapter, for QHPs and abide by the effective dates of coverage established by the Exchange in accordance with § 155.420(b) of this subchapter.
2. (b)Notification of effective date. A QHP issuer must notify a qualified individual of his or her effective date of coverage.