Depreciation is part of Cost of Goods Sold when the asset being depreciated physically helps produce inventory, and it is an operating expense when the asset supports general business functions instead. A stamping press on the factory floor and the building that houses it generate depreciation that gets absorbed into inventory and only hits the income statement as COGS once the finished goods are sold. The depreciation on a sales manager’s car, the accounting department’s laptops, or the corporate headquarters never touches COGS and is expensed in the period it is incurred. The classification turns on what the asset does, not what it is.
How Production Depreciation Reaches COGS
Depreciation on a factory machine, production line, or manufacturing building does not go straight to the income statement. It travels through the inventory accounts first. Under GAAP’s absorption costing rules, all manufacturing costs have to be absorbed into the cost of inventory, and that includes fixed overhead like depreciation on production assets. ASC 330-10-30 requires companies to allocate both variable and fixed production overhead to each unit of inventory based on normal production capacity.
The path is sequential. Depreciation on a production asset is calculated for the period and classified as manufacturing overhead. That overhead is allocated to Work-in-Process inventory as goods move through production. When products are finished, the costs move to Finished Goods inventory. The depreciation stays locked inside that inventory value on the balance sheet until the product sells. Only at the point of sale does it move from the balance sheet to the income statement as part of COGS.
Consider a $500,000 stamping machine that depreciates $100,000 per year. If the company sells only half its production during the year, $50,000 of that depreciation sits in Finished Goods inventory at year-end. It will not reduce net income until those remaining units sell. Overproducing can temporarily inflate reported profits because a chunk of fixed costs stays parked on the balance sheet rather than flowing through to COGS.
When Depreciation Is an Operating Expense Instead
Depreciation on assets that do not contribute to making inventory is a period cost. It hits the income statement in the period it is incurred regardless of how many units the company sells. Depreciation on a corporate headquarters, the accounting department’s computers, and a regional sales manager’s company car all fall into this category.
These costs never enter the manufacturing overhead pool and are never allocated to Work-in-Process or Finished Goods inventory. They appear under operating expenses on the income statement, typically grouped with other selling, general, and administrative costs. The result: this depreciation reduces operating income but has no effect on gross profit. Gross profit reflects only production costs, so keeping non-production depreciation out of COGS gives a cleaner view of how efficiently the company manufactures its products.
Function determines classification, not the asset type. A forklift operating in the factory warehouse is a production asset whose depreciation enters COGS. An identical forklift at a corporate distribution center used for non-manufacturing purposes is a period expense. Companies with assets that serve both production and administrative purposes need to allocate the depreciation between the two categories based on actual usage.
The Tax Side: UNICAP Requires Capitalization
For federal income tax, the IRS enforces a parallel requirement through the Uniform Capitalization rules under Section 263A of the Internal Revenue Code. The provision requires taxpayers to capitalize both the direct costs and a proper share of indirect costs allocable to property they produce or acquire for resale. Depreciation on production equipment is squarely within the indirect costs that must be capitalized into inventory rather than deducted as a current expense.1eCFR. 26 CFR 1.263A-1 – Uniform Capitalization of Costs
UNICAP does not stop at manufacturers. Retailers, wholesalers, and other resellers must also capitalize certain indirect costs into their inventory. For resellers, the capitalizable costs include purchasing costs, handling costs, off-site storage and warehousing costs, and related mixed service costs. Depreciation on vehicles, equipment, and warehouse facilities used in those activities is part of that calculation.2Internal Revenue Service. Examining a Reseller’s IRC 263A Computation
This catches some business owners off guard. A retailer who owns a warehouse might assume all depreciation on it is overhead to deduct immediately. Under Section 263A, depreciation on that warehouse must be capitalized into inventory cost and only deducted as the inventory is sold. The same logic applies to delivery trucks, storage equipment, and similar assets tied to getting goods ready for sale.
Small Business Exemption
Not every business has to deal with UNICAP. The Tax Cuts and Jobs Act created an exemption for small business taxpayers whose average annual gross receipts over the preceding three tax years do not exceed $25 million, adjusted annually for inflation.3Internal Revenue Service. Section 263A Costs for Self-Constructed Assets The inflation-adjusted threshold rises each year, so businesses near the line should check the current figure in IRS guidance for the tax year in question.
A qualifying business is not required to capitalize indirect costs like depreciation into inventory under Section 263A. It can use a simpler inventory method and deduct those costs more quickly. That is a meaningful cash flow advantage for smaller manufacturers and resellers because it avoids the complexity of tracking which portion of depreciation is locked in unsold inventory versus deductible in the current year.
The exemption does not change the GAAP requirement. For financial reporting, absorption costing still applies. A small manufacturer might use absorption costing in its audited financial statements while taking a more immediate deduction for the same depreciation on its tax return, producing a book-tax difference that has to be tracked.
Why Book Depreciation and Tax Depreciation Rarely Match
Even when depreciation is correctly capitalized into COGS under both GAAP and tax rules, the dollar amounts will almost certainly differ. For financial reporting, companies typically use straight-line depreciation over an estimated useful life with a salvage value. For tax, the IRS assigns mandatory recovery periods under the Modified Accelerated Cost Recovery System and generally uses an accelerated depreciation method with no salvage value.4Internal Revenue Service. Publication 946 – How to Depreciate Property
Most manufacturing equipment falls into the 5-year or 7-year MACRS property class and is depreciated using the 200% declining balance method for tax purposes. A machine depreciated over 10 years on a straight-line basis for the financial statements might be written off over 5 years on an accelerated basis for tax. MACRS front-loads deductions, producing larger tax depreciation in the early years and smaller amounts later.
These timing differences create deferred tax liabilities on the balance sheet. In early years, tax depreciation flowing into COGS exceeds book depreciation in COGS, producing lower taxable income relative to book income. The situation reverses in later years. Companies reconcile these differences on Schedule M-1 of the corporate tax return and track the resulting deferred tax effects in their financial statements.
Why the Classification Matters
Getting depreciation classification right has real consequences for how a business reads on paper. Gross profit, calculated as sales minus COGS, is the metric investors and lenders use to evaluate production efficiency and pricing power. If manufacturing depreciation is incorrectly excluded from COGS and buried in operating expenses, gross profit is overstated. Pricing decisions based on that inflated margin could leave a manufacturer selling products below their true cost without realizing it.
The balance sheet is equally affected. Inventory that does not include its fair share of manufacturing overhead, including production depreciation, is understated. For a company carrying significant unsold inventory, the understatement can be material enough to affect loan covenants tied to asset values or current ratios.
Analysts comparing manufacturers within the same industry rely on consistent application of absorption costing across companies. When one company capitalizes depreciation into inventory properly and another does not, the gross margins are not comparable. Auditors focus on this classification during inventory testing precisely because the judgment calls around what qualifies as a production asset versus an administrative asset have meaningful effects on reported profitability.