Abstract: Methods and apparatus for improved electromagnetic interference (EMI) shielding and thermal performance in integrated circuit (IC) packages are described. A die-up or die-down package includes a protective lid, a plurality of ground posts, an IC die, and a substrate. The substrate includes a plurality of ground planes. The IC die is mounted to the substrate. Plurality of ground posts is coupled to plurality of ground planes that surround IC die. Protective lid is coupled to plurality of ground posts. The plurality of ground posts and the protective lid from an enclosure structure that substantially encloses the IC die, and shields EMI from and radiating towards the IC die. The enclosure structure also dissipates heat generated by the IC die during operation.