Exhibit 99.1 News Release For more information contact: Media Relations: Sophia Marshall Senior Vice President, Communications Fiserv, Inc. sophia.marshall@fiserv.com Investor Relations: Walter Pritchard Senior Vice President, Investor Relations Fiserv, Inc. walter.pritchard@fiserv.com For Immediate Release Fiserv Reports Fourth Quarter and Full Year 2025 Results GAAP revenue growth of 1% in the quarter and 4% for the full year; GAAP EPS decreased 8% in the quarter and increased 18% for the full year; Organ ...