The following table includes the nonregulated annual composite depreciation rate ranges and nonregulated depreciable life ranges for AEP. Depreciation rate ranges and depreciable life ranges are not meaningful for nonregulated property of AEPTCo, APCo, I&M, OPCo, PSO and SWEPCo for 2020, 2019 and 2018. (a) SWEPCo’s nonregulated property, plant and equipment is depreciated using the straight-line method over a range of 3 to 20 years. NA Not applicable. SWEPCo provides for depreciation, depletion and amortization of coal-mining assets over each asset’s estimated useful life or the estimated life of each mine, whichever is shorter, using the straight-line method for mining structures and equipment. SWEPCo uses either the straight-line method or the units-of-production method to amortize mine development costs and deplete coal rights based on estimated recoverable tonnages. SWEPCo includes these costs in fuel expense. For regulated operations, the composite depreciation rate generally includes a component for non-ARO removal costs, which is credited to Accumulated Depreciation and Amortization on the balance sheets. Actual removal costs incurred are charged to Accumulated Depreciation and Amortization. Any excess of accrued non-ARO removal costs over actual removal costs incurred is reclassified from Accumulated Depreciation and Amortization and reflected as a regulatory liability. For nonregulated operations, non-ARO removal costs are expensed as incurred.  The Registrants record ARO in accordance with the accounting guidance for “Asset Retirement and Environmental Obligations” for legal obligations for asbestos removal and for the retirement of certain ash disposal facilities, wind farms, solar farms and certain coal-mining facilities. I&M records ARO for the decommissioning of the Cook Plant. The Registrants have identified, but not recognized, ARO liabilities related to electric transmission and distribution assets as a result of certain easements on property on which assets are owned. Generally, such easements are perpetual and require only the retirement and removal of assets upon the cessation of the property’s use. The retirement obligation is not estimable for such easements since the Registrants plan to use their facilities indefinitely. The retirement obligation would only be recognized if and when the Registrants abandon or cease the use of specific easements, which is not expected. Asset Retirement Obligations (Applies to all Registrants except AEPTCo) 403 SWEPCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 3.1% 35 - 75 2.9% 35 - 75 2.9% 35 - 75 Transmission 2.2% 45 - 75 2.4% 45 - 75 2.3% 45 - 75 Distribution 2.9% 15 - 78 2.9% 15 - 78 2.9% 15 - 78 Other 5.7% 5 - 64 5.6% 5 - 64 6.3% 5 - 64 PSO 2020 2019 2018 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 2.7% 35 - 65 2.5% 40 - 70 2.4% 40 - 70 Transmission 2.3% 47 - 73 2.4% 50 - 73 2.2% 50 - 73 Distribution 2.7% 15 - 67 2.7% 25 - 70 2.7% 25 - 70 Other 8.5% 5 - 52 7.6% 5 - 55 8.0% 5 - 55 2020 2019 2018 Functional Class of Property Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges (in years) (in years) (in years) Generation 3.6% - 4.0% 15 - 59 3.2% - 21.2% 15 - 59 3.4% - 22.3% 15 - 59 Transmission 2.5% 30 - 40 2.5% 30 - 40 2.4% 40 Distribution NA NA 2.3% 40 2.3% 40 Other 16.1% 5 - 50 (a) 17.6% 5 - 50 (a) 16.3% 5 - 50 (a)