| Acadian Gas Pipeline coastal use permit P19971312 pipeline | Acadian Gas Pipeline System | LA | | |
| Acadian Gas Pipeline coastal use permit P20180253 pipeline | Acadian Gas Pipeline System | LA | | |
| Acadian Haynesville Extension | Enterprise Products Partners | LA | In service 2011 | |
| Acadiana Project | Kinder Morgan Louisiana Pipeline LLC/Acadiana Project | LA | In service 2021 | |
| Access Northeast Project | Algonquin Gas Transmission, LLC | | | |
| Access South Project | Texas Eastern Transmission, LP | AL, KY, MS, OH, PA, TN, WV | In service 2017 | |
| Access South/Adair Southwest/Lebanon Extension | Texas Eastern Transmission, LP | KY, MS, OH | 2017–2018 | |
| Accident Storage Filed Enhancement Project | Texas Eastern Transmission, LP | MD | | |
| Ackerman Road Natural Gas Pipeline Project | Columbia Gas of Ohio | OH | | |
| Acquire Stage Coach Lateral | Central New York Oil & Gas Company, LLC | NY, PA | In service 2006 | |
| Acquisition of Riviera Lateral | Florida Southeast Connection, LLC | FL | | |
| Acuna Export Crossing | | TX | In service 2004 | |
| Ada Compressor Station Project | Viking Gas Transmission Co | MN | In service 2023 | |
| Adair Southwest Project | Texas Eastern Transmission, LP | KY, OH, PA, WV | In service 2017 | |
| Adaline Compressor Station Horsepower Replacement | Columbia Gas Transmission, LLC | WV | | |
| Adaline Compressor Station Replacement | Columbia Gas Transmission, LLC | WV | | |
| Adaline-Seneca Compressor Relocation | Columbia Gas Transmission, LLC | WV | | |
| Adelphia Gateway Pipeline | Adelphia Gateway, LLC | DE, PA | In service 2022 | |
| Adjustment to West-Central NCHP Pipeline Project | Columbia Gas of Ohio | OH | | |
| Adjustment to the Intel Pipeline Project | Columbia Gas of Ohio | OH | | |
| Aegis Ethane Pipeline | Enterprise Products Partners | TX, LA | In service 2015 | |
| Aethon Interconnects | | TX | | |
| Agler Road NCHP Pipeline Project | Columbia Gas of Ohio | OH | | |
| Agua Blanca Pipeline | WhiteWater | TX | In service 2018 | |
| Aguirre Offshore Gas Port Project | Excelerate Energy L.l.c. | | | |
| Aiken Compressor Expansion Project | Carolina Gas Transmission, LLC | SC | 2024 | |
| Air Liquide Large Industries U.s. coastal use permit P20121020 pipeline | Air Liquide Large Industries U.s. LP | LA | | |
| Air Liquide Large Industries U.s. coastal use permit P20151063 pipeline | Air Liquide Large Industries U.s. LP | LA | | |
| Air Liquide Large Industries U.s. coastal use permit P20181269 pipeline | Air Liquide Large Industries U.s. LP | LA | | |
| Air Products And Chemicals coastal use permit P20071873 pipeline | Air Products & Chemicals Inc | LA | | |