The design and administration of the plan, including the Cash Balance Benefit Program, shall comply with the applicable provisions of the Internal Revenue Code and the Revenue and Taxation Code. The Teachers' Retirement Board may amend the plan to comply with the applicable federal laws and regulations to the extent permitted by law, to establish or revise the minimum interest rate, to declare additional earnings credit, to declare additional annuity credit, and to adopt and amend actuarial assumptions for all purposes under the plan.