Via travel.state.gov:
Updated: May 10, 2019: Note that while Mexico is listed as a “Level 2: Exercised Increased Caution” country, the following five states in Mexico are considered “Level 4: Do Not Travel ” locations:
- Colima state
- Guerrero state
- Michoacán state
- Sinaloa state
- Tamaulipas state
We understand that Mexico is the only country that the State Department breaks down this way.
Five states in Mexico are also Level 4.