IBM has announced that DARPA has selected it for Stage C, the third phase of the Quantum Benchmarking Initiative (QBI). DARPA launched QBI in 2024 to determine whether an industrially useful fault-tolerant quantum computer can be built by 2033, and it defines such a system as one whose computational value exceeds its cost. In Stage C, DARPA’s independent verification and validation (IV&V) team moves past paper plans to test IBM’s hardware, technology, systems engineering, and architecture to determine whether IBM can build a fault-tolerant quantum computer.
IBM is one of four companies DARPA moved into Stage C the same day, alongside Atom Computing with neutral atom arrays, Diraq with silicon spin qubits, and IonQ with trapped ions. Microsoft and PsiQuantum reached the stage earlier through US2QC, the pilot program that preceded QBI, which brings the Stage C group to six. DARPA says QBI is not a competition, and QBI Managing Director Micah Stoutimore said that “Stage C is where we begin moving from plans to proof.”
Jay Gambetta, Director of IBM Research and IBM Fellow, said the selection “validates the strength of IBM’s path to building a fault-tolerant quantum computer,” and added that “IBM expects to deliver the first fault-tolerant system in 2029.” That system is IBM Quantum Starling, which IBM laid out last year. IBM says more than 340 organizations across financial services, healthcare, materials science, academia, and government use its quantum computers and its Qiskit software as scientific tools.
Progression Metrics and Hardware Verification Milestones
Stage A asked each company for an initial technical concept of a cost-effective, fault-tolerant quantum computer with a plausible path to realization in the near term, and DARPA announced several Stage A performers in April 2025. Stage B, a yearlong review, required a fcomprehensiveresearch and development plan along with its risks and mitigation approaches. Stage C is the first phase in which evaluators test the hardware itself, and DARPA expects to promote more companies into it.
IBM says its Starling work has stayed on course since it laid out the plan, citing demonstrations of core hardware components for fault tolerance and faster error-correction decoding. Those include the experimental IBM Quantum Loon processor, which IBM says demonstrated all the key processor components needed for fault-tolerant quantum computing, and real-time decoding of qLDPC error correction codes in under 480 nanoseconds, which IBM reported a full year ahead of schedule.
On the processor side, IBM calls the 120-qubit Nighthawk r2 its fastest quantum processor to date, rated at more than 100,000 circuits per second, and it is available now on the IBM Quantum Platform. For the systems that will house Starling, IBM reported in August that it had coupled and operated two prototype cells of its modular cryogenic architecture in Poughkeepsie, New York. Each cell has its own vacuum chamber, cooling hardware, and thermal shielding, and the design supports multi-chip, fault-tolerant systems.
Program Availability and Forward Roadmaps
Stage C puts IBM’s fabrication and systems engineering in front of DARPA’s evaluators ahead of Starling’s planned 2029 delivery. DARPA has not said how long Stage C will run. Stoutimore said the agency increasingly expects that someone will build a utility-scale quantum computer by 2033, but that it does not yet know which team or technical approach will get there.
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