Section 1115 of the Social Security Act gives the HHS Secretary authority to approve state "demonstration projects" that waive standard Medicaid rules, provided the experiment tests approaches consistent with the program's objectives. States apply to CMS, which reviews whether the project is budget-neutral to the federal government and furthers Medicaid goals. Waivers have been used to expand coverage, test managed-care models, and — controversially — add work requirements. Courts have reviewed whether HHS properly considered Medicaid's primary objective (health coverage for low-income people) when approving waivers that reduce enrollment.