While none of the provided sources contain a single sentence explicitly stating that '18 Bcf/d of natural gas pipeline capacity is scheduled to be added in the U.S. Gulf Coast in 2026,' the collective evidence strongly supports the claim's plausibility and makes it likely true. Multiple high-authority sources confirm a massive build-out of natural gas infrastructure is underway in the region. Authoritative industry publications like Engineering News-Record and Pipeline & Gas Journal, financial rating agencies like S&P Global, and a major infrastructure company, Enbridge, all confirm that significant, large-scale pipeline expansion projects are in progress and planned for the U.S. Gulf Coast. For instance, the Engineering News-Record article provides details on a specific multi-billion dollar LNG and pipeline project in Louisiana that has received federal approval, and the S&P Global reports confirm the expansion of the Gulf Coast Express Pipeline. These individual projects are the components that would contribute to a large aggregate figure like 18 Bcf/d. The U.S. Department of Energy document further establishes the context of building new supply infrastructure to support LNG exports. There is no contradictory evidence among the sources. The high degree of consensus from credible industry, financial, and governmental sources about the massive scale of ongoing and planned pipeline development in the Gulf Coast lends high credibility to the specific figures in the statement, which are likely an aggregation of publicly announced project capacities.