Waste container lid assemblies configured for attachment to a base having a lid body and cap portion slidably connected by a tether. The lid body having an opening sized to accept medical waste and restrict access to prevent individuals from reaching into the waste container through the opening. A slot is in the lid body to permit slidable movement of the tether through the slot such the cap can be moved from a resting position in which the opening is configured for receiving waste to a closed position such that the cap portion covers the opening.