CFR›Title 26›Chapter I›Part 1›Subject Group Continental Shelf Areas ContainsSections 1.638-1–1.640CorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 Sections 1.638-1 § 1.638-1 Continental Shelf areas. 1.638-2 § 1.638-2 Effective date. 1.639-1.640 §§ 1.639-1.640 [Reserved] Previous Consolidated Tax Liability Consolidated Tax Liability Next Contributions to a Partnership Contributions to a Partnership