He advised OPA when companies charges prices higher than government price ceilings. Hartley attacked Forer and colleagues for failing to grant pretrial conference and for appealing an adverse ruling. In August 1948, Forer and Greenberg resigned from the OPA. Later that year, David Rein joined Forer as private practice law partners in Washington, DC. They formed "Greenberg, Forer & Rein" with Herman Greenberg (who represented Julian Wadleigh just prior to his appearing as a witness during the Hiss-Chambers case). By 1949, the firm was still "Greenberg, Forer & Rein" at 1105 K Street NW in Washington. In 1950, they listed as "Forer & Rein" at 711 14 Street NW in 718 of the Kass Building. One of their early clients was the Food, Tobacco, Agricultural, and Allied Workers (FTA-CIO), a "Communist-led union." Another early client was the National Maritime Union. Together, they "represented more than 100 persons who had been termed 'unfriendly' witnesses by the House Committee on Un-American Activities, the Senate Internal Security Subcommittee of the Senate Judiciary subcommittee headed by the late senator Joseph McCarthy." In July 1947, Forer represented the FTA CIO against R.J. Reynolds before HUAC when two members pled the Fifth Amendment when asked to name communists. The FTA claimed accusations before HUAC by witness Ann Mathews, who name them among 15 communist members within the union, was really an attack by RJR against an 8,000 FTA strike. In September 1947 during his second appearance before HUAC, Gerhard Eisler asked to have Herman Greenberg and Joseph Forer represent him. On November 28, 1947, Forer, as acting chairman of the First Southest Chapter of the Southern Conference for Human Welfare, charged that members of a Congress Heights Citizens Association had made "references to vigilantism and to possible use of violence" to keep African-Americans out of that section of town. In December 1947, Forer asked that US Attorney General Tom C. Clark investigate. In early December 1947, Forer and Rein represented the National Maritime Union CIO (NMU) to file a challenge in the United States District Court for the District of Columbia, asking the court to invalidate a filing for financial data of unions. On January 26–28 and February 2, 1948, a hearing of the House Education and Labor Subcommittee, chaired by U.S. Representative Clare E. Hoffman, occurred on the topic of a strike by United Cafeteria and Restaurant Workers (Local 471) and its parent, the United Public Workers of America (UPWA), CIO, against Government Services, Inc. (GSI), which had already lasted nearly a month.