Section 1115 Medicaid demonstration waivers allow states to test new approaches in Medicaid that differ from what is required by federal statute.
Current areas of focus include targeted eligibility expansions, benefit expansions (particularly in the area of behavioral health, such as coverage of services provided in IMDs), and provisions related to social determinants of health. There are a few states who have utilized Section 1115 for medically prescribed meal plans.
The Kaiser Family Foundation does an excellent job of tracking these waivers across all states (in the USA).
Medicaid Waiver Tracker: Approved and Pending Section 1115 Waivers by State