A621the effect of perceived financial burden of the co-payment on antihypertensive adherence in patients within the GMS. We recruited community dwelling older adults (N= 1592) from 106 community pharmacies in the Republic of Ireland between March and May 2014, administering a structured telephone interview and following up at 12 months. Dispensing records from the pharmacy were linked to each patient interview. Perceived financial burden was assessed at baseline using a single questionnaire item. Adherence was assessed at 12 months using an 8-item self-report questionnaire and by calculating the proportion of days covered (PDC) from linked dispensing records. Results: At baseline 75.1% (n= 1152) of participants were GMS eligible and 30.1% of GMS participants reported feeling financially burdened by medication costs. In linear regression models adjusted for socio-demographics, medical history, and medication use, financially burdened GMS participants had significantly lower self-reported adherence (β = -0.32, 95% CI -0.51 to -0.14), although this was not evident with refill adherence (β = -0.03, 95% CI -0.08 to 0.02). ConClusions: Further work on the financial barrier to antihypertensive adherence within the GMS is warranted and its potential impact on long-term patient outcomes.