Species Native or Naturalized in the Continental US

USDA permits are not required for movements of native or naturalized millipede species within the Continental US. 

Importation and Possession of Exotic Species in the Continental US

Importation of exotic millipedes and any further interstate or intrastate movement requires a USDA permit. Permits for many species can be obtained without a containment facility. For example, I currently (11/25/2019) have the interstate movement permits for Acladocricus sp, Archispirostreptus gigas, Thyropygus pachyurus, Tonkinbolus caudulanus, Tonkinbolus dollfusi, Trigoniulus macropygus, Zoosphaerium neptunus. Importation permits usually require a containment facility. Also, a FWS permit is required to import any animal (exemptions for personal pets may apply) so research thoroughly to avoid confiscation at customs.