The Partnership recorded $0.1 million and $0.6 million of impairment expense during the year ended December 31, 2024 and 2023, respectively. The Partnership recorded $4.4 million of impairment expense during the year ended December 31, 2022 primarily related to assets whose undiscounted future net cash flows were less than their net book values. Of this amount, $2.6 million of impairment expense related to an asset with $4.3 million of net book value, resulting in a fair value of $1.7 million at December 31, 2022. The fair value of the impaired asset at December 31, 2022 was calculated using a discount rate of 15%. NRP compared the net book value of its mineral rights to estimated undiscounted future net cash flows. If the net book value exceeded the undiscounted future cash flows, the Partnership recorded an impairment for the excess of the net book value over fair value. A discounted cash flow model was used to estimate the level 3 fair value. Significant inputs used to determine fair value include estimates of future cash flows from coal sales and minimum payments, discount rate and useful economic life. Estimated cash flows are the product of a process that began with current realized pricing as of the measurement date and included an adjustment for risk related to the future realization of cash flows.

NATURAL RESOURCE PARTNERS LP 10-K