CFR › Title 26 › Part 1 › §1.263(c)-126 CFR §1.263(c)-1Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkFor rules relating to the option to deduct as expenses intangible drilling and development costs in the case of oil and gas wells, see § 1.612-4.