How the FEOC and prohibited foreign entity rules for batteries got here, and what's still to come.
| Date | What happened | Why it matters for battery buyers |
|---|---|---|
| 15 Nov 2021 | The infrastructure law defines "foreign entity of concern" (FEOC). | The term most people still use today comes from here. |
| 16 Aug 2022 | The Inflation Reduction Act applies FEOC limits to the electric vehicle credit (30D), for battery components and critical minerals. | The first time FEOC ties decided whether a battery-related credit could be claimed. |
| 16 Jun 2025 | Cut-off date later written into the 2025 tax law for existing contracts. | Products bought under a binding written contract signed before this date can, with conditions, be left out of the material assistance calculation. |
| 4 Jul 2025 | The 2025 tax law (Public Law 119-21) is signed. It adds "prohibited foreign entity" rules to credits including 45X, 45Y and 48E. | Supplier ownership and contracts become part of the buyer's tax picture for storage and manufacturing. |
| Tax years beginning after 4 Jul 2025 | The entity rules apply to 45X, 45Y and 48E claimants, and the material assistance rules apply to 45X components sold. | Battery manufacturers face both questions: who owns them, and where their inputs come from. |
| 30 Sep 2025 | The electric vehicle credit (30D) ends for vehicles acquired after this date. | The original FEOC rules fade in practice; the prohibited foreign entity rules carry the issue forward. |
| 1 Jan 2026 | The material assistance rules apply to 45Y and 48E facilities and storage that begin construction after 31 Dec 2025. | New storage projects need to know where their batteries and key parts came from. |
| 12 Feb 2026 | Treasury and the IRS issue Notice 2026-15, the first guidance on material assistance. | Sets interim rules taxpayers can rely on, and says each type of licensing arrangement is assessed separately for effective control. |
| By 31 Dec 2026 | Treasury must publish safe harbor cost tables. | Gives standard cost figures for the material assistance calculation. |
| To be announced | Proposed regulations on who counts as a prohibited foreign entity are expected. | Effective control and ownership tracing are the least settled areas; watch this space. |
See the plain-English explainer for what the rules ask, and the glossary for the terms.
General information, not legal or tax advice. Dates summarize public law and Treasury and IRS guidance as of November 2026; check the current rules with your advisers before acting.