How many months gap should there be in successive visitor travel

[Hummer]

Hi.

My parents visited me for 3 months between June-Aug'07 in their last visit even though they were given 6 months stay on I-94. They have multiple entry visa. I was wondering if I want to call them again in next few months e.g. around feb, is it ok?

How many months gap should there be in successive visits on a visitor visa.

[Murali]

There is no official limit or rules for such situations, however it is recommended that visitor should not spend more then total 6 months in a rolling 12 months time unless person extends the visit by filing extension.
Technically they can re-enter USA if they have multiple entry and visa BUT the officer at POE may have concern on their frequent trip and may issue less then 6 months of I94.