We present Part I of an annotated catalog of types in the Annelida collection of the Museum of Nature Hamburg, Leibniz Institute for the Analysis of Biodiversity Change. Part I includes the type specimens of 148 nominal species and subspecies belonging to Errantia incertae sedis and the Errantia clades Eunicida, Myzostomida, and Protodriliformia. The species are listed under these four groupings in alphabetical order by family and original binomen or trinomen. References to original descriptions, current accepted names, and remarks detailing additional information about type status and specimen condition are included