Rheumatoid arthritis (RA) is a chronic autoimmune disease with significant morbidity, mortality, and costs for the individual patient and for society. The purpose of this study was to examine welfare costs in patients with RA including their partners before and after initial diagnosis. Data were collected from population-based registers in the period from 1998 to 2009. A total of 25,547 Danish patients with a diagnosis of RA and 15,660 of their partners were identified and compared with 101,755 randomly selected age- and gender-matched controls and 62,681 control partners. The direct and indirect costs were calculated for patients and their partners and compared to matched controls. These included inpatient and outpatient treatment, medication, income from employment and social transfer payments. Patients with RA had statistically significantly more inpatient and outpatient costs than control subjects, i.e., treatment (€346 vs. €211), hospitalization (€1261 vs. €778), and medication use (€654 vs. €393). The costs associated with the patients were present 11 years before diagnosis of RA (€1592) compared with control subjects (€1172). Furthermore, income from employment was lower for patients (€14,023) than for control subjects (€17,196). Being a partner to a patient with RA was associated with high total welfare costs. This register-based study shows that RA has significant welfare costs for patients, their partners, and society. The differences in total health costs exist up to 11 years before the diagnosis of RA is established.