IRC 36B(b)(3)(C) states
Adjusted monthly premium. The adjusted monthly premium for an applicable second lowest cost silver plan is the monthly premium which would have been charged (for the rating area with respect to which the premiums under paragraph (2)(A) were determined) for the plan if each individual covered under a qualified health plan taken into account under paragraph (2)(A) were covered by such silver plan and the premium was adjusted only for the age of each such individual in the manner allowed under section 2701 of the Public Health Service Act.