Upon his return to the United States in June 1967, Modrzejewski was assigned to the United States Naval Academy in Annapolis, Maryland, as Commanding Officer of the Marine Barracks. In January 1970, he entered the Armed Forces Staff College, Norfolk, Virginia, and completed the course the following June. He then reported to Marine Corps Air Station, Kaneohe, Hawaii, for duty with Headquarters and Service Company, First Marine Brigade.
