William Schiller represents individuals, corporate, and university clients in a broad array of immigration matters. Many of the clients he represents are professors, researchers, scientists and post-doctoral scholars who apply for permanent residence as outstanding researchers and professors, and via national interest waiver and extraordinary ability immigration petitions. In addition, Wiliam's law practice involves the representation of highly-skilled professionals and individuals in a wide range of non-immigrant visa matters, as well as family-based immigration involving applications for permanent residence in the United States, asylum matters, removal, naturalization, consular processing, and other complex areas of immigration law.

As universities, medical centers, international students, faculty and postdoctoral scholars face increasingly complex and evolving immigration policies, William also leads Hinshaw’s Higher Education Immigration Team.

William lectures and publishes extensively on immigration law, and his client base is national and worldwide. He is an adjunct professor at Northwestern University, where he teaches a senior-level course on international human rights and U.S. refugee law.