Can you use 1-601 waiver for parents?

Can a citizen use the waiver to petition their parents? Let’s say if they have lived in the US for like 20 yrs undocumented and now have been back for about 5 yrs in their country living there. They would need to get some sort of waiver or would they have to wait 10 yrs till a petition can be filed for them? Does anyone know? I can’t seem to find the right info online. Just trying to help out a friend. Thanks so much in advance!

I-601 for unlawful presence requires a USC or LPR, Spouse or Parent as a qualifying relative. A child is not a valid qualifying relative for this waiver.

Like, if one of the grandparents is a USC or LPR that grandparent could be used for an I-601 with the child being a petitioner for an IR5. However in this case it looks like the parents will just have to wait out their ban.

Thank you for your answer! Could they start filing the I-130 form before the ban is over? Or would that get denied since they would still be under the ban?

I-130 can be filed beforehand however the visa can't be issued until after the ban expires.

So do you recommend waiting to file I-130 until the ban expires?

File it like 18 months before it expires.