Objective This study aims to provide insight into the distribution of care expenditures for patients with type 2 diabetes mellitus (T2DM)— across multiple healthcare service categories and medical specialties—who receive diabetes care in the primary care setting. Design Observational, matched case–control study. Setting In the Netherlands, T2DM-specific care is mainly provided in the primary care setting. However, many patients with T2DM also use secondary care for complications and comorbidities, either related or unrelated to their diabetes. Participants Patients with T2DM receiving diabetes care in primary care and participating in the Dutch Zwolle Outpatient Diabetes project Integrating Available Care cohort in the year 2011 were matched to persons without T2DM. Matching (1:2 ratio) was performed based on age, gender and socioeconomic status. Clinical data were combined with an all-payer claims database from 2011. Results In total, 43 775 patients with T2DM were identified of whom 37 240 could be matched with 74 480 controls. Total secondary care expenditures were €94 705 814, with a total annual median expenditure per patient of €2133 (1161 to 3340) for men and €2,535 (1374 to 5105) for women. The largest share of expenditures was on medication (26%), followed by secondary care (23%) and primary care services related (23%) to T2DM. The five most expensive specialties were: cardiology, surgery, internal medicine, orthopaedics and ophthalmology. Care expenditures for T2DM patients were twofold higher than those for persons without T2DM. Healthcare expenditures showed a skewed distribution, indicating that a small part of the studied population is responsible for a considerable part of the costs. Conclusions Expenditures among primary care treated T2DM patients are higher than non-diabetic matched controls. Medication is the largest share of T2DM care expenditures. The present study provides insights into healthcare expenditures for T2DM; this may enable more efficient healthcare planning and reimbursement.