This study aims to estimate the fee schedule for elderly long-term care facilities under Korea's Long-Term Care Insurance system, which has been in effect since 2008, by applying the Activity-Based Costing (ABC) method from the perspective of input costs. Additionally, it compares the estimated fees with the current fee schedule set by the Ministry of Health and Welfare. The existing long-term care insurance fee schedule was established based on a "standard model" grounded in normative criteria; however, there were differences in perspective between care service providers and the Ministry of Health and Welfare regarding the appropriateness and realism of these fees, and consensus was lacking. A time study was conducted at two elderly long-term care facilities located in regional areas, categorizing the services provided to residents into 14 activities, after which fees by care grade were estimated from an activity-based costing perspective. The analysis estimated per-person daily fees of 66,428 KRW for Grade 1, 66,508 KRW for Grade 2, 63,111 KRW for Grade 3, and 57,393 KRW for Grade 4. For reference, the Ministry of Health and Welfare's 2017 elderly long-term care facility fees were 59,330 KRW for Grade 1, 55,060 KRW for Grade 2, 50,770 KRW for Grade 3, and 50,770 KRW for Grade 4 on a daily basis, meaning that the activity-based cost estimates were approximately 12% to 24.3% lower than the current fees, ranging from a minimum of 7,098 KRW to a maximum of 12,341 KRW. The finding that current fees fall short of cost-based fee estimates implies that the current fee levels do not cover the costs incurred by service providers in delivering long-term care services. Moreover, the estimated fee for Grade 2 was found to be higher than that for Grade 1, which differs from the current fee structure where Grade 1 fees are higher than Grade 2 fees, suggesting that further consideration of the current grade-based fee structure is necessary. The contributions of this study are as follows: first, it estimated long-term care insurance fees by identifying the care service hours provided to facility residents as of 2017; second, it attempted a more refined fee estimation by applying the activity-based costing perspective to identify differentiated resource consumption items per resident; and third, this study's approach and analysis is the first since the implementation of Korea's Long-Term Care Insurance system in 2008, and is particularly meaningful in that fees were estimated from an input cost perspective rather than the institutional "standard model" perspective. However, the study's limitations include the fact that the sample consisted of only 190 residents across two institutions.