The SHOP Exchange: shall be a separate insurance market within the Exchange for small employers; and may not be merged with the individual market of the Individual Exchange. The SHOP Exchange shall be designed to balance: the viability of the SHOP Exchange as an alternative for qualified employers and their employees who have not been able historically to access and afford insurance in the small group market; the need for stability and predictability in employers’ health insurance costs incurred on behalf of their employees; the desirability of providing employees with a meaningful choice among high–quality and affordable health benefit plans; and the need to facilitate continuity of care for employees who change employers or health benefit plans. The SHOP Exchange shall allow qualified employers to: as required by regulations adopted by the Secretary under the Affordable Care Act, designate a coverage level within which their employees may choose any qualified health plan; or designate a carrier or an insurance holding company system, as defined in § 7–101 of this article, and a menu of qualified health plans offered by the carrier or the insurance holding company system in the SHOP Exchange from which their employees may choose. In addition to the options set forth in subsection (c) of this section, the SHOP Exchange also may allow qualified employers to designate one or more qualified dental plans and qualified vision plans to be made available to their employees. A qualified employer is not required to contribute to the qualified plan premiums of its employees. If a qualified employer chooses to contribute to the qualified plan premiums of its employees, the qualified employer shall: select a reference plan on which the contributions will be based; and make a contribution that is: a fixed percentage of the premium of the reference plan, based on the coverage level selected by the member and the member’s job classification, if otherwise permissible; or a dollar amount that ensures that all of the qualified employer’s employees with the same coverage level and job classification would pay the same amount if they purchased the reference plan. A reference plan selected under subparagraph (i)1 of this paragraph: under the employer choice model, shall be a qualified plan that is: offered by the carrier or insurance holding company system selected by the qualified employer; and among the qualified plans of the carrier or insurance holding company system selected by the qualified employer; or under the employee choice model, shall be a qualified plan offered by any carrier at the metal level selected by the qualified employer. On or after January 1, 2016, in order to continue to promote the SHOP Exchange’s principles of accessibility, choice, affordability, and sustainability, and as it obtains more data on adverse selection, cost, enrollment, and other factors, the SHOP Exchange: may reassess and modify the manner in which the SHOP Exchange allows qualified employers to offer, and their employees to choose, qualified health plans and coverage levels; in reassessing employer and employee choice, may consider options which would promote the additional objective of increasing the portability of employees’ health insurance as employees move from employer to employer or transition in and out of employment; and shall implement any modification of offerings and choice through regulations adopted by the SHOP Exchange.