Kodiak Sciences Inc. Notes to Consolidated Financial Statements (in thousands, except share and per share data) 91 Property and Equipment, Net Property and equipment are stated at cost, net of accumulated depreciation. Construction in progress reflects amounts incurred for construction or improvements of property or equipment that have not been placed in service. Construction in progress is transferred to specific property and equipment and depreciated when these assets are ready for their intended use. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which generally follows: Asset Category Useful Lives Furniture and Fixtures 5 years Machinery and Equipment 3 to 10 years Computer Software and Hardware 3 to 5 years Leasehold improvements Lesser of the useful life or the term of the respective lease Upon sale or retirement of assets, the costs and related accumulated depreciation are removed from the consolidated balance sheet and the resulting gain or loss is reflected in operations. Maintenance and repairs are charged to operations as incurred. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted net cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the assets. There have been no such impairments of long-lived assets in the years ended December 31, 2022 and 2021. Research and Development Expenses Costs related to research, design and development of products are charged to research and development expense as incurred. Research and development costs include, but are not limited to, payroll and personnel expenses, including stock- based compensation, laboratory supplies, outside services and allocated overhead, including rent, depreciation and utilities. Accrued Research and Development The Company has entered into various agreements with various third parties, including clinical investigator sites, contract research organizations (“CROs”) and contract manufacturing organizations (“CMOs”), to provide research and development activities. The Company’s accrued research and development costs are estimated based on the level of services performed, including the phase or completion of events, and contracted costs. Accrued clinical trial and related costs are estimated using data such as patient enrollment, clinical site activations or information provided by outside service providers regarding their actual costs incurred. Management determined accrual estimates through reports from and discussions with clinical personnel and outside service providers as to the progress of trials, or the services completed. The estimated costs of research and development provided, but not yet invoiced, are included in accrued and other current liabilities on the consolidated balance sheet. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to third parties under these arrangements in advance of the performance of the related services are recorded as prepaid expenses or other assets until the services are rendered. Stock-Based Compensation The Company accounts for stock-based compensation in accordance with the provisions of ASC 718, Compensation- Stock Compensation. The Company measures stock-based compensation expense for stock options and restricted stock units granted to its employees, directors and non-employees based on the estimated fair value of the awards on the grant date. The fair value of options is calculated using the Black-Scholes valuation model or the Monte Carlo simulation model, which requires the input of subjective assumptions, including (i) the calculation of expected term of the award, (ii) the expected stock price volatility, (iii) the risk-free interest rate, and (iv) expected dividends.