Abstract: Modular spa covers for insulating spa units are described herein. The modular spa covers can include a plurality of panels and a plurality of support structures. The plurality of support structures can be attached to at least one of the pluralities of panels to attached two or more of the plurality of panels to each other. The plurality of support structures can include at least one E-shaped support structure, at least one T-shaped support structure, and/or at least one H-shaped support structure. When attached to the plurality of panels, at least a portion of each of the plurality of support structures can be embedded within the plurality of panels. The plurality of panels and the plurality of support structures can be packaged inside a spa unit during transportation.