| Mercer Culinary WARN | July 9, 2025 | 35 | — | Ronkonkoma, NY | — |
| Prodose WARN | November 26, 2024 | 186 | — | Ronkonkoma, NY | — |
| UltraVolt WARN | October 29, 2024 | 37 | — | Ronkonkoma, NY | — |
| Southwest Airlines WARN | December 3, 2020 | — | — | Ronkonkoma, NY | — |
| Enterprise WARN | April 29, 2020 | 113 | — | Ronkonkoma, NY | — |
| Brookset Bus WARN | April 28, 2020 | 125 | — | Ronkonkoma, NY | — |
| SUNation Solar Systems WARN | April 14, 2020 | 128 | — | Ronkonkoma, NY | — |
| Crestline Hotels & Resorts Hilton Garden Inn Islip/MacArthur Airport WARN | April 7, 2020 | 34 | — | Ronkonkoma, NY | — |
| STAT Fire Sprinkler WARN | April 3, 2020 | 52 | — | Ronkonkoma, NY | — |
| HMSHost WARN | March 21, 2020 | 39 | — | Ronkonkoma, NY | — |
| St. Joseph School WARN | January 31, 2019 | 38 | — | Ronkonkoma, NY | — |
| Ingenious Designs LLC, a wholly-owned subsidiary of the Home Shopping Network WARN | October 17, 2018 | 66 | — | Ronkonkoma, NY | — |
| Lanco WARN | November 3, 2017 | 130 | — | Ronkonkoma, NY | — |
| Community Program Centers of Long Island WARN | March 29, 2017 | 33 | — | Ronkonkoma, NY | — |
| PCX Aerostructures WARN | January 10, 2017 | 45 | — | Ronkonkoma, NY | — |
| Quantum Medical Imaging, LLC, a subsidiary of Carestream Health WARN | April 20, 2016 | 83 | — | Ronkonkoma, NY | — |
| NBTY Inc. and NBTY Manufacturing New York WARN | October 20, 2014 | 5 | — | Ronkonkoma, NY | — |
| Suffolk Bus WARN | September 29, 2014 | — | — | Ronkonkoma, NY | — |
| The Community Program Centers of Long Island, Inc. Early Head Start/Head Start Programs WARN | April 30, 2014 | — | — | Ronkonkoma, NY | — |
| Suffolk Transportation Service, Inc./TERRAFINA Bus WARN | September 26, 2011 | 55 | — | Ronkonkoma, NY | — |
| Atlantic Detroit Diesel-Allison WARN | August 5, 2011 | 24 | — | Ronkonkoma, NY | — |
| National Hybrid WARN | June 3, 2010 | 84 | — | Ronkonkoma, NY | — |
| Parker Hannifin Corporation Electromechanical Division WARN | August 20, 2009 | 6 | — | Ronkonkoma, NY | — |
| USM Transfield WARN | July 16, 2009 | 88 | — | Ronkonkoma, NY | — |
| DHL Express WARN | December 5, 2008 | 60 | — | Ronkonkoma, NY | — |
| Carolina Precision Plastics WARN | September 25, 2006 | 84 | — | Ronkonkoma, NY | — |