Port of entry letter

[smitha]

Hi, my parents are planning to reach US by mid september and planning to stay for only 4 months. Do they need to present a letter at port of entry ( letter at port of entry for longer stay & itinerary) regarding the same ? or is it needed only if they plan to extend their duration of stay ?

Thank You.

[immihelp]

It is not really needed but good have. You can get sample letter from https://www.immihelp.com/usa-visas/visitor