OBJECTIVES With generous coverage and patients' full freedom to access different tiers of medical facilities, Taiwan's single payer national health insurance system is facing difficulties of escalating utilization and cost of out-patient care. Recently, outpatient co-payment has been largely increased in order to control unnecessary medical demands and encourage patients with minor illness of initial contact in primary care, but this policy has only shown limited impacts. To determine the relative importance of factors (attributes) associated with patients' choices on accessing different tiers of medical facilities, we conducted a qualitative study on hypertensive outpatients. METHODS Focus groups were conducted on hypertensive outpatients from different tiers (clinics, local, regional hospitals and medical centers) of medical facilities in Southern Taiwan. RESULTS Nine focus groups were conducted at local community (1), local hospital (2), regional hospital (2) and medical center (4), including 40 hypertensive participants. The saturated opinions indicated doctors' reputation and friendliness, tiers of hospitals, and transportation convenience as the three main considerations for participants to access different hospitals. Participants tend to visit a fixed doctors and hospitals because they believe hypertension needs a long-term, consecutive and quality treatment. Higher-tier medical facilities are symbolized as better medical care, drugs and equipments, yet the out-of-pocket payment is considered affordable, especially doctors prescribed continuous prescriptions to save patient's co-payment charge. Participants dislike being transferred from lower to higher tiers of medical facilities due to the inconvenient process and lack of price incentive. CONCLUSIONS By identifying attributes to hypertensive outpatients' choices of accessing medical facilities, we found the current co-payment policy does not impact on hypertensive patients' affordability and accessibility in Southern Taiwan. Future study is going to determine the relative importance of attributes and whether and how much higher co-payment charge can influence on patients' decisions to access different tiers of medical facilities.