Table of Contents Index to Financial Statements General and Administrative Expenses Taxes, Other than Income Taxes Full Cost Pool Amortization See  “Supplemental Oil and Gas Disclosures” in Item 8 of Part II of this Annual Report for additional information regarding our unevaluated costs excluded from amortization. In accordance with accounting guidance for Property, Plant and Equipment, assets held for sale are measured at the lower of carrying value or fair value less costs to sell. Because the assets outside the full cost pool met the criteria for held for sale accounting in the third quarter of 2018, we determined the carrying value of certain non-full cost pool E&P assets exceeded the fair value less costs to sell. As a result, an impairment charge of $15 million was recorded during the year ended December 31, 2018. Impairments 55 · General and administrative expenses decreased in 2018, compared to 2017, as a $20 million decrease in costs resulting from the mid-year implementation of cost reductions and decreased personnel costs was partially offset by a $4 million increase in legal settlement charges. · On a per Mcfe basis, excluding restructuring and legal settlement charges, general and administrative expenses per Mcfe decreased for the year ended December 31, 2018, compared to 2017, due to a 10% decrease in expenses and a 5% increase in production volumes. · On a per Mcfe basis, excluding restructuring and legal settlement charges, general and administrative expenses per Mcfe remained flat for the year ended December 31, 2017, compared to 2016, as a slight increase in expenses was offset by a 3% increase in production volumes. · Taxes other than income taxes per Mcfe may vary from period to period due to changes in ad valorem and severance taxes that result from the mix of our production volumes and fluctuations in commodity prices. Excluding $1 million of restructuring charges in 2018, taxes, other than income taxes, per Mcfe decreased $0.01 per Mcfe for the year ended December 31, 2018, compared to the same period in 2017, primarily due to an $8 million severance tax refund related to a favorable assessment on deductible expenses in Southwest Appalachia, a $1 million severance tax refund related to a favorable assessment on deductible expenses in the Fayetteville Shale, favorable property tax assessments, and property and sales tax refunds recorded in the first quarter of 2018. · On a per Mcfe basis, taxes, other than income taxes, remained flat for the year ended December 31, 2017 compared to 2016 as a slight increase in expense was more than offset by an increase in production volumes. · Our full cost pool amortization rate increased $0.06 per Mcfe for the year ended December 31, 2018, as compared to 2017. The increase in the average amortization rate resulted primarily from the addition of future development costs associated with proved undeveloped reserves recognized as a result of improved commodity prices. · The amortization rate is impacted by the timing and amount of reserve additions and the costs associated with those additions, revisions of previous reserve estimates due to both price and well performance, write-downs that result from full cost ceiling impairments, proceeds from the sale of properties that reduce the full cost pool, and the levels of costs subject to amortization. We cannot predict our future full cost pool amortization rate with accuracy due to the variability of each of the factors discussed above, as well as other factors, including but not limited to the uncertainty of the amount of future reserve changes. · Unevaluated costs excluded from amortization were $1.8 billion at December 31, 2018, and 2017, compared to $2.1 billion at December 31, 2016. The unevaluated costs excluded from amortization slightly decreased, as compared to 2017, as the evaluation of previously unevaluated properties totaling $361 million in 2018 was only partially offset by the impact of $299 million of unevaluated capital invested during the same period.