The US Senate adjourned late on 30 September and will return to Washington after the November midterm elections. The House adjourned for the midterm elections earlier in September. Congress is currently scheduled to return to session on 9 November.

Before leaving Washington, Senate Finance Committee member Steve Daines (R-MT) on 30 September introduced the Aligning Digital Assets with Principles of Taxation (ADAPT) Act (S. 5616). According to a press release, the 56-page bill would provide "comprehensive legislation to modernize the federal tax treatment of digital assets and establish clearer, more administrable rules for taxpayers, businesses and the Internal Revenue Service." The Senate bill is similar to the Digital Asset Tax Certainty Act (H.R. 10357), which the House Ways & Means Committee approved on 16 September.

The Daines crypto bill (1) includes a de minimis rule allowing no gain or loss to be recognized on smaller cryptocurrency transactions, (2) applies mark-to-market accounting rules to digital asset brokers and dealers, and (3) allows crypto to qualify for safe harbors to facilitate foreign investment in US markets. It also includes streamlining rules on charitable contributions of digital assets and applies wash sale rules and constructive sale rules to digital assets.

Among other things, the Senate bill would provide that income from digital asset validation supporting certain activities — staking, mining, etc. — is US-source if derived by a US person and foreign-source if derived by a foreign person. The bill would also apply a safe harbor under which foreign persons trading stocks, securities or commodities through US brokers or for their own account would not be considered engaged in a US trade or business involving traded digital assets.

The OECD on 30 September released the latest version of the OECD Model Tax Convention. The released version includes updates that were made in November 2025.