Pilot projections for Korea's local population from 2020 to 2040 were produced using NABO's new model that reflects recent lowest-low fertility and aging in society. According to the reference model (reference scenario) assuming the total fertility rate (TFR) will be 0.73 in 2040, the local population is projected to decrease to 47.17 million in 2040 from 50.02 million in 2020. However, according to the TFR rebound scenario assuming the rate to rise to 1.7 in 2040, the local population is projected to be 49.01 million in 2040, up 1.84 million from the reference scenario. The TFR has recorded under 1.0 for three consecutive years. If this lowest-low fertility rate continues until 2040, the population size would reduce significantly and negatively affect Korea's sustainable growth.