Extension for my parents visitor visa

[jayendran]

My parents came to USA last October (2017) and the I-94 expiration date is 1 year from the day they arrived.

Do i still need to apply for the extension after 180 days stay or they are fine until the I-94 expiration date. Because I have read in lot of forums that maximum allowed number of days to stay in B2 visa is 180 days and we need to apply for extension to stay after 180 days.  Please advise. 

[pontevecchio]

Run it by the local CBP Office maybe at the Airport.

You should arrange for them to leave within 6 months.