Boeing’s acquisition of major supplier Spirit AeroSystems has proven more expensive than initially projected. According to a Boeing regulatory filing, the manufacturer now estimates that customer contracts inherited from Spirit will cost $455 million more to fulfill than first calculated. This adjustment brings the total estimated burden of those agreements to $1.52 billion, representing a 43% increase over the estimate compiled in late December 2025, shortly after the acquisition was finalized.
The transaction, valued at approximately $8.4 billion, was completed on December 8, 2025. It integrated Spirit’s production lines for 737 fuselages along with major structural components for the 767, 777, and 787 programs back under Boeing's direct management. The acquisition also brought approximately 15,000 employees into Boeing. At the time, Boeing stated that uniting the companies under a single management structure would help stabilize production and improve manufacturing quality.
The rising acquisition costs have already impacted Boeing's financial outlook. On March 17, 2026, Chief Financial Officer Jay Malave cautioned that integration expenses had delayed the commercial aircraft division's expected return to profitability to 2027, which is one year later than previously forecast. Malave noted at an investor conference that companies do not obtain full access to all detailed financial information until transactions officially close, describing the impact as a short-term headwind.
These financial adjustments are occurring as Boeing increases its overall delivery output. Data released on September 8, 2026, showed that Boeing delivered 418 aircraft during the first eight months of 2026, up from 385 aircraft delivered during the same period in 2025. However, deliveries in August 2026 slipped to 51 from the 53 aircraft delivered in July, with 787 Dreamliner handovers dropping from ten in July to four in August.
Boeing has not disclosed which specific customers or aircraft programs contributed to the $455 million cost increase, stating that its assessment remains preliminary. Meanwhile, other parts of Spirit's original business have been divided or continue to serve external clients. Airbus took over operations related to its own aircraft programs when the transactions closed in December 2025, while Spirit's independent defense segment continues to supply structures for Northrop Grumman's B-21 bomber and Sikorsky's CH-53K helicopter. Other commercial customers include Bombardier and Rolls-Royce.
