Originally Posted by Matt-ADX

https://www.cnn.com/2017/02/24/polit...nal/index.html

Here CNN has more

The penalty for this type of violation of immigration law is deportation, and according to the ACLU, "civil removal proceedings far outnumber criminal prosecutions and remain the primary manner in which the federal authorities enforce the immigration laws."
If, however, an undocumented immigrant is deported and then returns to the US without permission, then that "illegal re-entry" constitutes a federal offense with different tiers of accompanying prison time.