Shachtmanism was a form of Trotskyism associated with Max Shachtman. It originated as a tendency within the US Socialist Workers Party in 1939 and Shachtmans supporters left that group to form the Workers party in 1940.

Although the split in the SWP was not over the class nature of the Russian state, contrary to popular mythology among many latter day Trotskyists, that was a major point in the internal polemics of the time. However the theory of "bureaucratic collectivism", the idea that Russia was ruled by a new bureaucratic class and was not capitalist, did not originate with Shachtman, but seems to have originated within the Trotskyist movement with Bruno Rizzi. Furthermore, it should be noted that members of the French Section of the Fourth International around Craipeau also held this analysis.

Regardless of its origins in the SWP, Shachtmanism's first advocate was not Shachtman but Carter, although he did not commit his ideas to paper. Nonetheless, we have the testimony of no less a figure than C L R James that this is a fact as he referred to the theory, from which he dissented, as Carters little liver pill. In the event the theory was never fully developed by anybody in the Workers Party and Shachtmans book, published many years later in 1961, consists earlier articles from the pages of New International with the political conclusions reversed.

Shachtmanites believe that the Stalinist rulers of Communist countries are a new (ruling) class, distinct from the workers; therefore, they go beyond Trotsky's description of Stalinist Russia as being a "degenerated workers' state". Max Shachtman described the USSR as a "bureaucratic collectivist" society. Other Trotskyist thinkers have described such societies as "state capitalist" and are often said to share a basic theoretical agreement with Shachtman.

Left Shachtmanism, influenced by Max Shachtman's work of the 1940s, sees Stalinist nations as being potentially imperialist and does not offer any support to their leadership. This has been crudely described as seeing the Stalinist and capitalist countries as being equally bad, although it would be more accurate to say that neither is seen as a more progressive alternative for the working class. A more prevalent term for Left Shachtmanism is Third Camp Trotskyism, the Third Camp being differentiated from capitalism and Stalinism. This position is broadly held by the Workers' Liberty grouping in Australia and the United Kingdom, and by both the International Socialist wing of Solidarity and the International Socialist Organization in the United States. The foremost left Shachtmanite was Hal Draper a writer who worked as a librarian at the University of California, Berkeley and became influential with left wing students during the Free Speech Movement.

Social democratic Shachtmanism, called "Right Shachtmanism" by detractors, later developed by Shachtman and espoused by the Social Democrats USA holds Stalinist nations to be worse than Western capitalism, and will as a result often side with the U.S. government in international conflicts against Stalinist groups, such as the Vietnam War.