The Promoting Innovation in Pipeline Efficiency and Safety Act of 2025 (PIPES Act of 2025) reauthorizes appropriations for federal pipeline safety programs and grants for gas and hazardous liquid pipelines from fiscal years 2026 through 2029. It allocates specific funding for operational expenses, one-call notification programs, emergency response, and community information grants. A new grant program is established to assist publicly owned natural gas distribution systems in updating and replacing high-risk or leaking infrastructure to enhance safety and reduce monetary losses. A major focus of the bill is the explicit inclusion of carbon dioxide pipelines within federal safety regulations. The Act amends existing law to define "carbon dioxide" and "carbon dioxide pipeline facility," integrating them into various aspects of pipeline safety oversight. This expansion includes applying safety standards, state program certifications, emergency response grants, and technical safety standards committees to carbon dioxide infrastructure, along with requirements for vapor dispersion modeling. The bill aims to improve regulatory efficiency and transparency by requiring the Secretary of Transportation to provide periodic public updates on the status of all outstanding rulemaking mandates. It also mandates regular review and updating of incorporated industry standards, ensuring public accessibility to these standards. A new Office of Public Engagement is established within the Pipeline and Hazardous Materials Safety Administration (PHMSA) to proactively engage with stakeholders and the public on pipeline safety practices. To strengthen PHMSA's capabilities, the Act authorizes an increase of up to 30 full-time equivalent employees with advanced technical expertise for the Office of Pipeline Safety. It also streamlines the special permit program by limiting waiver terms to known safety risks and setting an 18-month review deadline for applications. Furthermore, the bill provides an opportunity for formal administrative law judge hearings for enforcement matters with high proposed civil penalties or significant compliance costs. The legislation mandates several studies to inform future safety standards and practices. These include a study on the use of composite materials for hydrogen pipelines , a GAO study on geohazard mitigation requirements, and a National Academies study on the effectiveness of integrity management regulations . Another GAO study will examine existing natural gas pipeline systems that blend hydrogen, identifying necessary operational and infrastructure changes. The bill strengthens excavation damage prevention by amending grant criteria for states to encourage the adoption of leading practices for one-call programs and requiring detailed reporting on their implementation. It also directs an assessment of how pipeline operators share safety information with the public and emergency responders. A GAO study is required to evaluate the feasibility and need for a localized emergency alert system for pipeline incidents. The Act increases the maximum civil penalty for pipeline safety violations and establishes new criminal penalties for knowingly causing defects or disrupting pipeline operations. It also addresses the reconfirmation of maximum allowable operating pressure (MAOP) for previously tested natural gas transmission pipelines, establishing a working group to develop recommendations and mandating a subsequent rulemaking. Additionally, it creates a confidential, voluntary information-sharing system for pipeline safety data, governed by a multi-stakeholder board, with confidentiality protections.