We present a unified framework for envisioning precision healthcare informatics (PHI). The framework, presented as a high-level ontology, deconstructs PHI into six dimensions derived from the informatics and healthcare disciplines—the structure, function, and semiotics of informatics, and the stakeholders, care, and value of precision healthcare. Each dimension is articulated as a taxonomy of its constituent elements. Thus, the framework encapsulates the combinatorial complexity of PHI and can be used to describe its 37,800 potential components in natural English. The framework will help envision PHI systematically, systemically, an symmetrically in contrast to the often simplified, selective, and skewed approaches. The framework can be used to map the state-of-the-research, -practice, and -policy on PHI, discover the gaps within and between the states, and develop a roadmap for the future. It can be scaled and extended as PHI evolves by adding dimensions, and extending/refining the taxonomies.