Artificial Intelligence Data Center Moratorium Act (S.4214) — twenty megawatts and liquid cooling draw the line, and lifting it requires a law meeting five conditions
A Senate bill halting construction and upgrading of AI data centers above a defined scale until legislation is enacted that safeguards the public from the dangers of artificial intelligence. The definition turns on a rated power capacity above twenty megawatts combined with racks designed for twenty kilowatts or more, or on liquid cooling. Its House companion H.R.9442 is textually identical.
Bill overview (primary data)
- Bill numberS. 4214
- TypeSenate Bill
- Congress119th Congress
- Latest actionRead twice and referred to the Committee on Commerce, Science, and Transportation.（2026-03-25）
Key points
- The target is defined by specification rather than by size language: above 20 megawatts, 20 kilowatts or more per rack, or liquid cooling.
- Contiguous sites under common ownership or control count as a single facility, narrowing the room to subdivide below the threshold.
- The moratorium has no expiry; it lifts only when a law securing five conditions is enacted and expressly terminates it.
- The Secretary of Energy must report to Congress quarterly and publish those reports, and section 4 imposes export controls on computing infrastructure hardware.
- The companion House bill H.R.9442 is textually identical, but timing, sponsor, referral and cosponsor count all differ.
- Coverage is defined by plant specification — over 20 megawatts, 20 kilowatts per rack, liquid cooling — with adjacent sites counted together.
1The line is drawn in power and cooling
What distinguishes this bill is that it does not call its target a large data center and leave it there. It defines the target by specification: a maximum rated capacity or peak load above 20 megawatts, a design delivering 20 kilowatts or more to a single rack, cooling that circulates liquid to components or submerges hardware in it.
Rack-level power delivery and liquid cooling are only required where computing is packed densely. Rather than asking operators to declare a purpose, the drafting infers purpose from how the facility is built. Counting contiguous sites under common ownership as one facility narrows the room to fall below the threshold by subdividing.
2The text sets conditions for restarting, not for stopping
The moratorium does not expire. Ending it requires a law that secures five things and that expressly terminates the moratorium. The five are that consumer utility bills do not rise, that climate change is not worsened and the environment not harmed, that affected communities can approve or reject construction, that no government subsidy is provided, and that union jobs with strong labor standards are created.
Upstream of those sit two further requirements: federal review and approval of AI products before release, and arrangements ensuring the gains from AI and robotics reach workers. Because this is a pause until the next statute rather than a pause for a fixed term, when it ends rests with Congress.
3Identical wording on two different political trajectories
Set against the companion House bill H.R.9442, the text matches line for line. The paths do not. The Senate bill was introduced on 2026-03-25 by Sen. Bernard Sanders (I-VT) alone and referred to the Committee on Commerce, Science, and Transportation.
The House bill followed three months later, on 2026-06-24, from Rep. Alexandria Ocasio-Cortez (D-NY-14), was referred to both Energy and Commerce and Foreign Affairs, and carried 14 cosponsors as of 2026-08-31.
The findings in section 2 name industry executives and researchers and quote them directly, and they cite the March 2023 open letter calling for a pause on giant AI experiments, signed by more than a thousand people. Findings carry no operative force, but they show which materials the sponsor put forward as the basis.
4Drawing the line by how the plant is built
What marks this bill is that it does not call the target a "large data centre" vaguely but defines it by the specification of the plant.
| Criterion | Content |
|---|---|
| Maximum rated power or peak load | Exceeding 20 megawatts |
| Supply to a single server rack | Designed to deliver 20 kilowatts or more |
| Cooling method | Circulating liquid through components, or immersing equipment in liquid |
| How sites are counted | Adjacent sites held by the same or a controlling entity count as one |
Power per rack and liquid cooling are both features unnecessary except in plant packing computers densely. Rather than requiring a declared purpose, the drafting infers purpose from how the plant is built, and counting adjacent sites together narrows the room to split a site below the threshold. The moratorium does not end on a date: ending it requires a statute securing five things and expressly terminating the moratorium.
Why it matters
Drawing the line by specification means the scope does not depend on what an operator declares the facility is for. From the build side, choices about rack-level power delivery and cooling would themselves determine whether a site falls under the rule, and the provision aggregating adjacent sites anticipates subdivision as an avoidance route. Matching text in both chambers indicates the question is not confined to one of them.
FAQ
Would every data center stop?
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How does it differ from the House bill?
Sources (primary)
Source: Congress.gov (Library of Congress; U.S. legislative materials, public domain). Links go to the official site.
- Congress.gov (bill page, original)
- S. 4214（119th Congress）