Plan for the conduct of air operations in support of the Fleet Marine Force, supervise and train selected Marine Corps Reserve units, provide administrative and logistical support for selected Marine Corps Reserve units, and ensure mobilization readiness.
The squadron was deactivated 21 September 1945 and reactivated 1 July 1946 at Naval Air Station Miami, Florida, as Marine Fighting Squadron 142 and assigned to Marine Air Detachment, Naval Air Reserve Training Unit, Naval Air Station, Miami, Florida. The "Flying Gators" were reassigned in December 1946 to the Marine Air ReserveTraining Command, Naval Air Reserve Training Unit, Naval Air Station, Miami, Florida. The squadron was redesignated 1 April 1949 as Marine Fighter Squadron 142, Marine Air Reserve Training Command, Naval Air Station Miami, Florida, later itself redesignated in February 1952 as Marine Corps Air Station Miami, Florida. The squadron was redesignated in September 1953 as Marine Fighter Squadron 142, Marine Air Reserve Training Detachment, Marine Air Reserve Training Command, Marine Corps Air Station Miami, Florida. The squadron was yet again redesignated on 15 May 1958 as Marine Attack Squadron 142 and relocated during March 1959 to Naval Air Station Jacksonville, Florida. The squadron was reassigned during January 1971 to the 4th Marine Aircraft Wing, Fleet Marine Force before relocating during December 1978 from NAS Jacksonville to nearby Naval Air Station Cecil Field, Florida. Soon thereafter, in January 1979, the squadron was reassigned to Marine Aircraft Group 42 Detachment, 4th Marine Aircraft Wing, Fleet Marine Force and, a year later in January 1980, reassigned again to Marine Aircraft Group 42, Detachment A, 4th Marine Aircraft Wing, Fleet Marine Force. During the early 70's the squadron flew the J-65 powered A-4L before transitioning to the newer J52-P-408 powered A-4F. The last A-4L departed in the summer of 1976. As active duty A-4 units transitioned to the AV-8B during the 80's, their A-4M's replaced reserve unit A-4F's. The squadron converted from the A-4M Skyhawk II to the F/A-18A Hornet and was formally redesignated on 21 December 1990 as Marine Fighter Attack Squadron 142 . In August 1997, due to the pending BRAC 93-mandated closure of NAS Cecil Field by the end of 1999, the squadron relocated to Naval Air Station Atlanta, approximately North of Atlanta in Marietta, Georgia. It was the second F/A-18 squadron to be transferred to NAS Atlanta, having been preceded by the Naval Air Reserve's Strike Fighter Squadron TWO ZERO THREE, which was also previously based at NAS Cecil Field. VMFA-142 became part of the Department of the Navy TACAIR concept, which integrates both Marine Corps F/A-18 fighter/attack squadrons and Navy F/A-18 strike fighter squadrons into Navy carrier air wings. As a Marine Air Reserve squadron, VMFA-142 integrated into Carrier Air Wing Reserve TWENTY. In May 2000, in a first for CVWR-20, five Marine Hornets from VMFA-142 joined the wing for carrier qualification, qualifying all five pilots. Three of the Hornets then flew to Naval Station Roosevelt Roads, Puerto Rico for additional Fleet training operations.