The purpose of this memorandum is to clarify how the hazardous waste regulations for universal waste and recycling apply to lithium-ion batteries. The proportion of electric cars powered by lithium-ion batteries on the road is rising rapidly; lithium-ion batteries also power our electronics and, increasingly, lawnmowers, e-scooters, electric bicycles, and many other devices. The growth of the circular economy for lithium battery materials is vital as the focus turns to how to eventually manage lithium-ion batteries at the end of their lives. Recycling lithium-ion batteries returns valuable critical minerals to the economy, both conserving resources and reducing the overall energy use needed to produce new batteries.