Goodwill allocated to disposal

  
assets. For the year ended December 31, 2020, the Company recorded goodwill adjustments of $71 million relating to the acquisition of Hydroid, primarily related to allocations to other intangible assets. For the year ended December 31, 2020, the Company allocated $35 million of goodwill at its Technical Solutions segment to an asset group that was classified as held for sale.   
For the years ended December 31, 2021 and 2020, the carrying amounts of goodwill changed as follows:

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| ($ in millions) |  | Ingalls |  | Newport News |  | Technical Solutions |  | Total |
| Balance as of December 31, 2019 |  | $ | 175  |  |  | $ | 721  |  |  | $ | 477  |  |  | $ | 1,373  |  |
| Acquisitions |  | —  |  |  | —  |  |  | 350  |  |  | 350  |  |
| Adjustments |  | —  |  |  | —  |  |  | (106) |  |  | (106) |  |
|  |  |  |  |  |  |  |  |  |
| Balance as of December 31, 2020 |  | 175  |  |  | 721  |  |  | 721  |  |  | 1,617  |  |
| Acquisitions |  | —  |  |  | —  |  |  | 1,024  |  |  | 1,024  |  |
| Adjustments |  | —  |  |  | —  |  |  | (13) |  |  | (13) |  |
|  |  |  |  |  |  |  |  |  |
| Balance as of December 31, 2021 |  | $ | 175  |  |  | $ | 721  |  |  | $ | 1,732  |  |  | $ | 2,628  |  |

  
Other Intangible Assets  
The Company performs tests for impairment of long-lived assets whenever events or circumstances suggest that long-lived assets may be impaired. In connection with the Alion purchase in 2021, the Company recorded $720 million of intangible assets pertaining to customer relationships and existing contract backlog, which is being amortized using the pattern of benefits method over a weighted-average life of 15 years. In connection with the SIS purchase in 2020, the Company recorded $13 million of intangible assets pertaining to technology and existing contract backlog, which is being amortized using the pattern of benefits method over a weighted-average life of ten years. In connection with the Hydroid purchase in 2020, the Company recorded $76 million of intangible assets pertaining to existing contract backlog, customer relationships, and technology, which is being amortized using the pattern of benefits method over a weighted-average life of nine years.   
The Company's purchased intangible assets are being amortized on a straight-line basis or a method based on the pattern of benefits over their estimated useful lives. Net intangible assets consist primarily of amounts relating to customer relationships and existing contract backlog within Technical Solutions, as well as nuclear-powered aircraft carrier and submarine program intangible assets, with an aggregate weighted-average useful life of 29 years based on the long life cycle of the related programs. Aggregate amortization expense for the years ended December 31, 2021, 2020, and 2019, was $86 million, $56 million, and $47 million, respectively.  
The Company expects amortization for purchased intangible assets of $141 million in 2022, $129 million in 2023, $108 million in 2024, $98 million in 2025, and $80 million in 2026.  
12. INCOME TAXES  
The Company's earnings are primarily domestic, and its effective tax rate on earnings from operations for the year ended December 31, 2021, was 12.5%, compared with 14.1% and 19.6% for 2020 and 2019, respectively.   
For the year ended December 31, 2021, the Company's effective tax rate differed from the federal statutory tax rate primarily as a result of a tax loss associated with the sale of the Company's oil and gas business and estimated research and development tax credits for 2021 and prior years. For the year ended December 31, 2020, the Company's effective tax rate differed from the federal statutory tax rate primarily as a result of estimated research and development tax credits for prior years. For the year ended December 31, 2019, the Company’s effective tax rate differed from the federal statutory tax rate primarily as a result of estimated research and development tax credits for 2019 and prior years.  
Non-current state income taxes include deferred state income taxes, which reflect the change in deferred state tax assets and liabilities, and the tax expense or benefit associated with changes in state unrecognized tax benefits in the relevant period. These amounts are recorded within operating income. Current period state income tax expense is charged to contract costs and included in cost of sales and service revenues in segment operating income.  
85
