In this section, “self–employed individual” includes an individual who: is the sole owner of a sole proprietorship, limited liability company, C corporation, or S corporation; and is the only individual employed by the sole proprietorship, limited liability company, C corporation, or S corporation. A self–employed individual who is a resident of the State may elect to participate in the Program in accordance with regulations adopted by the Secretary under subsection (c) of this section. On or before July 1, 2028, the Secretary shall adopt regulations that establish an optional self–employed enrollment program and include: contribution amounts; benefit amounts; and enrollment procedures.