Top Fusion Energy Companies in the United States | 2026 Guide
The United States is home to the most active and best-funded fusion energy ecosystem in the world. Between private startups that have collectively raised billions, a network of national laboratories with decades of plasma physics expertise, and growing government investment, the U.S. fusion landscape offers more career opportunities than any other country.
This guide covers the major U.S. fusion companies and research institutions, organized by geographic cluster — because where you work matters as much as who you work for. For global coverage including European and Asian players, see our directory of top emerging fusion companies worldwide.
Greater Boston / New England
The Boston area has emerged as the center of gravity for private fusion in the U.S., anchored by the MIT ecosystem and the concentration of engineering talent in the region.
Commonwealth Fusion Systems (CFS)
Location: Devens, Massachusetts
Approach: Compact tokamak with high-temperature superconducting (HTS) magnets
Funding: ~$2.9 billion raised, making CFS the best-funded private fusion company in the world
CFS is the undisputed leader of the private fusion sector. Spun out of MIT's Plasma Science and Fusion Center in 2018, the company is building SPARC — a compact tokamak designed to demonstrate net energy gain from fusion. Their breakthrough HTS magnet technology enables a smaller, more powerful reactor design. SPARC is under active construction at CFS's 47-acre campus in Devens, with first plasma targeted for 2027. Beyond SPARC, CFS is already planning ARC, a commercial pilot power plant.
CFS is also the largest private employer in the fusion industry, with 800+ employees and growing. They hire across engineering (mechanical, electrical, nuclear, controls, manufacturing), physics, operations, technicians, and corporate functions. Their internship and co-op program is one of the most competitive in the field.
MIT Plasma Science and Fusion Center (PSFC)
Location: Cambridge, Massachusetts
While technically a university lab rather than a company, MIT PSFC is deeply intertwined with CFS and remains one of the world's premier fusion research institutions. It offers graduate research positions, postdoctoral fellowships, and undergraduate research opportunities that serve as a direct pipeline into the private fusion workforce.
Pacific Northwest
Washington State has become a fusion hub, driven by Helion Energy's ambitious timeline and the region's strong aerospace and tech talent base.
Helion Energy
Location: Everett, Washington
Approach: Pulsed field-reversed configuration (FRC)
Funding: Over $600 million raised
Helion is pursuing one of the most aggressive timelines in fusion. The company has built seven generations of prototype reactors — more iterations than any other fusion company. Their latest machine, Polaris, achieved 150 million degree plasma temperatures in early 2026 and became the first privately developed fusion device to operate with deuterium-tritium fuel. Helion has a power purchase agreement with Microsoft to sell electricity from its first 50 MW commercial plant (under construction near Malaga, Washington) starting in 2028, plus a 500 MW offtake deal with Nucor.
Helion offers competitive compensation including equity, a 5% 401(k) match, and strong PTO. They hire engineers, physicists, and operations staff, with summer internship positions available.
Zap Energy
Location: Everett, Washington
Approach: Sheared-flow stabilized Z-pinch
Funding: Over $200 million raised
Zap Energy takes a fundamentally different approach from most fusion companies — their Z-pinch design doesn't require expensive superconducting magnets or lasers, potentially making fusion reactors far cheaper to build. The company spun out of the University of Washington and Lawrence Livermore National Laboratory and is backed by investors including Chevron, Lowercarbon Capital, and Breakthrough Energy Ventures.
Southern California
California's deep aerospace and defense talent pool makes it a natural home for fusion companies.
TAE Technologies
Location: Foothill Ranch, California
Approach: Beam-driven field-reversed configuration (FRC), targeting aneutronic hydrogen-boron fuel
Funding: Over $1.3 billion raised
Founded in 1998, TAE is the longest-running private fusion company. Their unique approach ultimately aims to use hydrogen-boron fuel — a reaction that produces virtually no radioactive waste. TAE's current machine, "Norman," has achieved steady plasmas above 75 million degrees. The company holds over 1,600 patents and has attracted investment from Google, Chevron, and Goldman Sachs. In late 2025, TAE announced a merger with Trump Media & Technology Group that, if completed, would create one of the world's first publicly traded fusion companies. TAE plans to begin construction of a 50 MWe utility-scale fusion plant in 2026.
Other U.S. Startups to Watch
Pacific Fusion
Location: Not yet publicly disclosed
Approach: Magnetically-driven inertial confinement with pulsed electromagnetic power
Funding: $900 million Series A — one of the largest debut funding rounds in fusion history
A newer entrant backed by prominent investors including Eric Lander. Pacific Fusion is pursuing a novel approach that combines elements of magnetic and inertial confinement.
Avalanche Energy
Location: Seattle, Washington
Approach: Micro-scale fusion reactors using electrostatic confinement
Funding: ~$84 million raised
Avalanche is going small where others go big — their reactor is measured in centimeters rather than meters. The compact approach allows rapid iteration and testing, sometimes twice per week. Originally supported by a defense innovation contract, Avalanche is targeting both commercial power and portable energy applications.
Realta Fusion
Location: Madison, Wisconsin
Approach: Mirror machine (magnetic mirror confinement)
Spun out of the University of Wisconsin-Madison, Realta is reviving and modernizing the magnetic mirror concept. They hire plasma physicists and diagnostics engineers to develop their WHAM experimental device.
Thea Energy
Location: New York
Approach: Planar-coil stellarator
Thea Energy is reinventing the stellarator — a twisted magnetic confinement device — using computer-controlled arrays of simpler planar coils instead of the complex 3D-shaped magnets traditional stellarators require. The company offers internships and hires across physics, engineering, and operations.
U.S. National Laboratories
The national lab system remains the backbone of American fusion research and a major employer. These institutions offer stable careers, strong benefits, and access to unique experimental facilities.
Princeton Plasma Physics Laboratory (PPPL)
Location: Princeton, New Jersey
The only U.S. national lab dedicated solely to plasma physics and fusion energy. PPPL conducts fundamental research, operates experimental devices, and runs one of the most competitive undergraduate and graduate research programs in fusion. It's a primary pipeline for fusion scientists entering both the public and private sectors.
Oak Ridge National Laboratory (ORNL)
Location: Oak Ridge, Tennessee
ORNL's Fusion Energy Division works on plasma boundary modeling, materials science for fusion, and reactor technology development. They participate in the DOE's SULI internship program and hire across research, engineering, and technical roles.
Lawrence Livermore National Laboratory (LLNL)
Location: Livermore, California
Home to the National Ignition Facility (NIF), where fusion ignition was first achieved in December 2022. LLNL focuses on inertial confinement fusion using high-powered lasers. They hire physicists, engineers, and computational scientists, with student internship programs available.
Sandia National Laboratories
Location: Albuquerque, New Mexico
Sandia operates the Z Machine, the world's most powerful pulsed-power facility, which is used for inertial confinement fusion experiments and related research. They hire across physics, engineering, and computational science.
The U.S. Fusion Job Market
The concentration of fusion activity in the U.S. creates the world's deepest job market for fusion professionals. Between the private companies listed above and the national lab network, there are hundreds of open positions at any given time — spanning every degree level from associate to PhD.
If you're transitioning from aerospace, defense, or another industry, the U.S. fusion ecosystem is where you'll find the most opportunity. And if you're a student, the combination of company internships and national lab research programs makes the U.S. the best place to launch a fusion career — see our guide to fusion internships and co-ops.
For salary expectations across all these employers, see our Fusion Energy Salary Guide.
See who's hiring right now. Browse open positions from U.S. fusion companies and labs on our job board.
Company information reflects publicly available data as of April 2026. Funding figures are approximate and based on reported rounds. Last updated: April 2026.