Inclusion Criteria: - Participants recently (within the last 24 months before enrollment) diagnosed with established moderate to severe active RA - Participants naïve of abatacept and who, at their physician's discretion, are initiated with abatacept according the German label/SmPC (Summary of product characteristics) Exclusion Criteria: - Participants who are currently included in any interventional clinical trial in RA Other protocol defined inclusion/exclusion criteria could apply