Irwin P. Altschuler began his career in 1975 with the U.S. Customs Service and U.S. Treasury Department when those agencies were charged with enforcing unfair trade remedy laws of the United States. He advised senior Customs, Treasury and Justice Department officials on major antidumping cases, and spent substantial time in Japan investigating and resolving those disputes. Irwin also served as a liaison with a number of U.S. attorneys, prosecuting cases of fraud and other serious customs violations.

Since entering the private sector in 1980, Irwin has built a practice that retains its original focus on trade remedies litigation and enforcement proceedings and has grown to include trade policy matters and, increasingly, business issues arising from accessing and defending international markets. Irwin's practice has a strong focus on Mexico. During the past 30 years, he has represented some of Mexico's largest corporations and Mexican government entities, in international trade and other complex legal, policy and business matters.