Abstract This paper is a continuation of a previous work, SPE191734 (Deng, 2018) which focused on integrating additive manufacturing into completions technology to develop a packer of ultra-high expansion with a 10,000 psi pressure rating at 300°F. This paper presents the work that further extends the packer's capabilities to withstand pressures of 15,000 psi and temperatures up to 350°F while maintaining high expansion, tested to ISO 14310 V3 pressure acceptance criteria. Three factors primarily contributed to its successful qualification. First, new backup technology eliminated traditional design limitations imposed by conventional manufacturing and enabled us to design and print a backup system with ultra-expansion capacity and superior conformability. Second, an internally developed polymer that exhibits great elongation and extrusion resistance played a key role in holding the 15,000 psi pressure reversals at 350F in the ultra-expansion states. Finally, a state-of-the-art design process seamlessly integrated design, material characterization, design optimization, and test validation, enabling rapid failure diagnosis and design iterations to ensure rigorous customer requirements were satisfied. This integrated process reduces development costs and shortens time to market. An ultra-high expansion openhole HPHT packer was developed as a result of advances in Additive Manufacturing technology, polymeric materials, and a holistic design process. Physical test validation demonstrated: 15,000 psi pressure reversal and 15 minute hold at 350°F. Displacement of 0.5 in and 15,000 pressure reversal at 350°F. Elastomer element system remained in good visual condition in post-test inspection. This is the industry's first commercial completion packer with an Additive Manufactured element containment system. It is also the industry's first ultra-expansion packer to demonstrate HPHT capability.