Exhibit 99.1 May 4, 2026 Analyst Contact: Erin Dailey 918-947-7441 Media Contact: Leah Harper 918-947-7123 ONE Gas Announces First Quarter 2026 Financial Results; Affirms 2026 Financial Guidance "Our positive performance through a historically warm winter underscores the resilience of our business model and our ability to drive long‑term value while sustaining customer affordability," said Robert S. McAnnally, chief executive officer. "We are confident in our strategic plan and remain on track to achieve ou ...