MDU RESOURCES GROUP INC

Index

Note 8 -Goodwill and Other Intangible Assets

The carrying amount of goodwill at the natural gas distribution and construction services segments, which remained unchanged, was $345.7 million and $143.2 million, respectively, at both December 31, 2023 and 2022. No impairments of goodwill have been recorded in these periods.

At October 31, 2023, the fair value substantially exceeded the carrying value at the Company's construction services reporting unit. The Company's annual impairment testing indicated the natural gas distribution reporting units fair value is not substantially in excess of its carrying value ("cushion"). Based on the Company's assessment, the estimated fair value of the natural gas distribution reporting unit exceeded its carrying value, which includes $345.7 million of goodwill, by approximately 4 percent as of October 31, 2023. The decrease in the natural gas distribution reporting unit's cushion from the prior year was primarily attributable to the risk adjusted cost of capital increasing from 6.4 percent in 2022 to 6.7 percent 2023, which directly correlates with the treasury rates at the date of the test. The natural gas distribution reporting unit is at risk of future impairment if projected operating results are not met or other inputs into the fair value measurement model change.

Other amortizable intangible assets at December 31 were as follows:

Amortization expense for amortizable intangible assets for the years ended December 31, 2023, 2022 and 2021, was $2.1 million, $2.2 million and $2.5 million, respectively. The amounts of estimated amortization expense for identifiable intangible assets as of December 31, 2023, were: