All participants must purchase at least the basic plan unless, to the extent that it is consistent with federal law, the participant is a person who has retired from a branch of the United States military and has been provided with health coverage through a federal plan and that participant provides proof of that coverage, or the participant has opted out of the state’s basic plan according to the provisions in Section 1308.3 of this title. On or before January 1 of the plan year beginning July 1, 2001, and July 1 of any plan year beginning after January 1, 2002, the Oklahoma Employees Insurance and Benefits Board shall design the basic plan for the next plan year to ensure that the basic plan provides adequate coverage to all participants. All benefit plans, whether offered by the State and Education Employees Group Insurance Board, a health maintenance organization or other vendors shall meet the minimum requirements set by the Board for the basic plan.