The following list shows the taxa of the phylum Sipuncula down to the subgenus level. The numbers shown in (*) are the number of species considered valid by Cutler, 1994. For a complete list of taxa to the species level, with junior synonyms, see 'Sipuncula Taxa"

Phylum Sipuncula - 144 species

     Class Sipunculidea 
         Order Sipunculiformes
               Family Sipunculidae  (24)
                    Genus Sipunculus (10)
                         Subgenus Sipunculus (8)
                         Subgenus Austrosiphon (2)
                    Genus Xenosiphon (2)
                    Genus Siphonosoma (10)
                    Genus Siphonomecus (1)
                    Genus Phascolopsis (1)
 
         Order Golfingiiformes
               Family Golfingiidae  (36)
                    Genus Golfingia (10)
                         Subgenus Golfingia (9)
                         Subgenus Spinata (1)
                    Genus Nephasoma (23)
                         Subgenus Nephasoma (22)
                         Subgenus Cutlerensis (1)
                    Genus Thysanocardia (3)
               Family Phascolionidae  (29)
                    Genus Phascolion (25)
                         Subgenus Phascolion (11)
                         Subgenus Isomya (6)
                         Subgenus Montuga (2)
                         Subgenus Lesenka (5)
                         Subgenus Villiophora (1)
                    Genus Onchnesoma (4)
              Family Themistidae  (10)
                    Genus Themiste (10)
                         Subgenus Themiste (5)
                         Subgenus Lagenopsis (5)
 
   Class Phascolosomatidea 
         Order Phascolosomatiformes
               Family Phascolosomatidae  (23)
                    Genus Phascolosoma (18)
                         Subgenus Phascolosoma (16)
                         Subgenus Fisherana (2)
                    Genus Apionsoma (4)
                         Subgenus Apionsoma (3)
                         Subgenus Edmondsius (1)
                    Genus Antillesoma (1)
 
         Order Aspidosiphoniformes
               Family Aspidosiphonidae  (22)
                    Genus Aspidosiphon (19)
                         Subgenus Akrikos (5)
                         Subgenus Aspidosiphon (7)
                         Subgenus Paraspidosiphon (7)
                    Genus Lithacrosiphon (2)
                    Genus Cloeosiphon (1)