In a health policy sense, a complaint filed because of dissatisfaction with the quality of care by a provider or with customer service or some other action by a health plan. Medicare fee-for-service, Medicare health maintenance organizations and Medicare Part D prescription drug plans, as well as Medicaid and most other health plans, have formal procedures for handling and responding to grievances. If a Medicare beneficiary files a grievance against a hospital, a Quality Improvement Organization will review the case and guarantee the patient’s stay, possibly free-of-charge, until the review has been completed. Under the Affordable Care Act (ACA), all consumers will have the right to challenge decisions, including coverage denials and rescissions, made by their health plans. (Also see appeal.)