My wife is planning to travel our home Country(India) for a period of 4 months. We have 9 months old Son. He has Valid US passport and valid PIO(Person of Indian Origin) Card . I am aware if any one other than parents required notarized consent letter from parents to accompanying infant to travel out side USA.

What if one of parent is accompanying infant to travel outside USA? Does notarized consent letter from other parent is mandatory?