; and (B) such period does not exceed 2 months (or 3 months in the case of a late enrollee). (2) Affiliation period (A) Defined For purposes of this title, the term affiliation period means a period which, under the terms of the health insurance coverage offered by the health maintenance organization, must expire before the health insurance coverage becomes effective. The organization is not required to provide health care services or benefits during such period and no premium shall be charged to the participant or beneficiary for any coverage during the period. (B) Beginning Such period shall begin on the enrollment date. (C) Runs concurrently with waiting periods An affiliation period under a plan shall run concurrently with any waiting period under the plan. (3) Alternative methods A health maintenance organization described in paragraph (1) may use alternative methods, from those described in such paragraph, to address adverse selection as approved by the State insurance commissioner or official or officials designated by the State to enforce the requirements of this part for the State involved with respect to such issuer. 199A. Extension of dependent coverage (a) In general A group health plan and a health insurance issuer offering group or individual health insurance coverage that provides dependent coverage of children shall continue to make such coverage available for an adult child (who is not married) until the child turns 26 years of age. Nothing in this section shall require a health plan or a health insurance issuer described in the preceding sentence to make coverage available for a child of a child receiving dependent coverage. (b) Regulations The Secretary shall promulgate regulations to define the dependents to which coverage shall be made available under subsection (a). (c) Rule of construction Nothing in this section shall be construed to modify the definition of dependent as used in the Internal Revenue Code of 1986 with respect to the tax treatment of the cost of coverage. 199B. Annual