A State Plan is a contract between a state and the Federal Government describing how that state administers its Medicaid program. It gives an assurance that a state abides by Federal rules and may claim Federal matching funds for its Medicaid program activities. The state plan sets out groups of individuals to be covered, services to be provided, methodologies for providers to be reimbursed and the administrative requirements that States must meet to participate.
States frequently send a state plan amendment, otherwise referred to as a SPA, to the Centers for Medicare and Medicaid Services (CMS) for review and approval. There are many reasons why a state might want to amend their state plan. For example, the state may wish to implement changes required by Federal or state law, Federal or state regulations, or court orders. States also have the flexibility to request permissible program changes, make corrections, or update their plan with new information.
CMS maintains the Medicaid.gov website, where more information regarding SPAs can be found.