Useful lives by asset category are as follows:
Asset CategoryUseful Life
Computer equipment and software
1 to 3 years
Office furniture and equipment5 years
Manufacturing and laboratory equipment
5 to 10 years
Fixed assets, net, summarized by major category, consist of the following (in thousands):
 December 31,
 20232022
Machinery and equipment$121,773 $118,684 
Leasehold improvements61,826 61,302 
Computer equipment and software17,186 15,360 
Office furniture and equipment2,543 2,420 
Construction in progress105,905 103,226 
Total309,233 300,992 
Less: accumulated depreciation(135,306)(117,480)
Fixed assets, net$173,927 $183,512 
For information on useful lives by asset category, refer to Note 2, Summary of Significant Accounting Policies.

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.