Creates the Social Media Age Restriction Act. Provides that an operator of a social media platform shall take reasonable steps, including the implementation of an age assurance system, to prevent a child from creating or maintaining an account on the social media platform. Provides that an operator may enter into an agreement with application distribution services or device manufacturers to allow for user information to be shared for age assurance purposes. Provides that the provision does not apply to a parent or guardian who allows a child to use an account held by the parent or guardian. Sets forth provisions concerning a 30-day cure period and civil penalties. Provides that an operator shall have 180 days after the effective date of the Act to comply with the requirements of the Act. Effective immediately.