Re-entry to USA on B1/B2 Tourist Visa

[Smithaks]

Hi,
My parents got their B1/B2 Visa in 2009 which is valid till 2019. They visited USA once in 2009 and stayed for 2 months. If they are planning to visit again this year,
1. Do we have to go through any approval process ?
2. Do they need to carry any document other than passport with visa (valid till 2019) , tickets & insurance ?

Thanks in advance,
Smitha

[scientist2016]

1. No.
2. No.