This review focuses on introducing and explaining the rare earth metal mediated group transfer polymerization (REM-GTP) of polar monomers and is composed of three main sections: poly(vinylphosphonate)s, surface-initiated group transfer polymerization (SI-GTP), and extension to N-coordinating Michael-type monomers (2-vinylpridine (2VP), 2-isopropenyl-2-oxazoline (IPOx)). The poly(vinylphosphonate)s section is divided into two parts: radical, anionic, and silyl ketene acetal group transfer polymerization (SKA-GTP) of vinylphosphonates in comparison to REM-GTP, and properties of poly(vinylphosphonate)s. The mechanism of vinylphosphonate REM-GTP is discussed in detail for initiation and propagation including activation enthalpies Delta H-dagger and entropies Delta S* according to the Eyring equation. SI-GTP is presented as a method for surface functionalization, and recent trends for 2VP and IPOx polymerization are summarized. This review will serve as a good resource or guideline for researchers who are currently working in the field of rare earth metal mediated polymerization catalysis as well as for those who are interested in beginning to employ rare earth metal complexes for the synthesis of new materials from polar monomers.