Gate 4 shelves of coffee and rum are your first clue
IMAS shows up all over Terminal A at SJO, with duty free stores near gates 4, 5, 9, 15 and 20. Stock is similar at each spot, so pick the one closest to your gate instead of backtracking across the concourse. All locations sit post-security, after you clear outbound immigration.
Hours vary by gate, but the gate 4 and gate 5 branches tend to open earliest with the morning bank of North America flights, then shut around the last departures near 22:00. Late-night runs are safer at gates 15 and 20, which usually stay open closer to the final US departures. Don’t count on a 24-hour option anywhere here.
This is standard duty free: liquor, perfume, chocolate and Costa Rican coffee stacked floor-to-ceiling. You’ll see local rums in the USD $10–$25 range, plus mid-shelf tequila and whisky priced a bit under US supermarket levels. Coffee bags often run 500 g for around USD $8–$12, and you can usually grab smaller 250 g packs if you’re tight on space.
Lines spike at the IMAS near gate 9 during the 11:00–14:00 departure wave when multiple US carriers board at once. If your boarding pass shows gates 15 or 20 and you have 10 spare minutes, prices match and lines there are usually shorter. Quick tip: check the liquor allowances for your destination before buying, because staff here won’t track your customs limits for you.