OBJECTIVES: The demand of tertiary emergency care increases in aging societies. However, in regions affected by the Great East Japan Earthquake, the supply is deteriorating due to the closure of hospitals. This study aimed to forecast and visualize future recovery in the supply-demand balance of tertiary emergency care in an earthquake-affected region using geographic information systems (GIS). METHODS: This study targeted Iwate, Miyagi, and Fukushima prefectures, which were struck by the 2011 Great East Japan earthquake. Demand for urgent tertiary care in 2020 was forecasted by multiplying the incidence of patients with life-threatening conditions derived from transportation records by national population projections. Supply was quantified by using access time to Emergency Medical Centers (EMCs). We estimated disparities between demand and supply with two indicators: 1) Coverage rate: the proportion of patients within 45 minutes to EMCs by ambulance, and 2) Institute-to-Patient Ratio (IPR): 1/the number of patients within 45 minutes to EMCs. IPR was visualized on a map. We compared these indicators for 2010 and 2020 in order to evaluate the recovery situation. RESULTS: The annual incidence per 100,000 is expected to increase from 253.30 to 326.80. The coverage rate will increase from 60.3% (8,657/14,365) to 67.5% (11,726/17,378), and IPR will decrease from 0.0013 (IQR: 0.0010–0.0017) to 0.0012 (IQR: 0.0009–0.0017). Regional differences across prefectures in 2020 are estimated to be 53.5% (86.5% in Miyagi - 33.3% in Iwate) for coverage rate, and 0.0006 (0.0015 in Miyagi to 0.0009 in Iwate) for IPR. CONCLUSIONS: Nine years after the earthquake, access time to emergency care will decrease, whereas the supply-demand balance may deteriorate in accordance with an increase in demand. Regional disparities of access will arise in the future. Further research will be required to closely examine optimal resource allocation to assist in the recovery.