The GRAPPA-OMERACT psoriatic arthritis (PsA) working group is in the process of updating the PsA core domain set to improve and standardize the measurement of PsA outcomes. Work streams comprise literature reviews of domains and outcome measurement instruments, an international qualitative research project with PsA patients to generate domains important to patients, outcome measurement instrument assessment, conduct of domain consensus panels with patients and physicians, and evidence-based selection of instruments. Patient research partners are involved in each of the projects. The working group will present findings and seek endorsement for the new PsA core domain set, outcome measurement set, and research agenda at the OMERACT meeting in May 2016.