Live-in care is requiring a guarantor even though client (elderly patient) has full means to pay for services.

Find a different company.

Don’t do it. Look for an alternative. Don’t start off with red flags.

I guess its for the live-in care? Want to make sure they get paid if Mom dies. If a parent is POA, they are guaranteeing that the money is there ascGMs representative. Putting POA behind their name means they are not personally responsible. May be a good idea to consult with a lawyer.

Bottom line, do not guarantee anything it can become a trap. They know that ppl die, just another way to secure funds from concerned others.

No one knows exactly how long Grandma will live, 6 months is their benchmark.

This sounds weird to me also. Hopefully your parents are your Grandmother's PoA. Maybe they can help her put the required funds in an escrow account rather than have a guarantor? But if Medicare pays for hospice... what's going on here?

Hospice care is fully paid for by Medicare.
Something is wrong here.
NEVER sign as a guarantor of ANYTHING.
If you are not POA now and grandmother is capable of making a trusted family member the POA (mentally capable) then get this done by an attorney (they can visit care homes). Then it is signed with your grandmother's name and the POA can put "by Grand Daughter as POA."

If you sign it is YOUR BILL.
You need to know that right now and tell anyone who asks you to sign your name on any documents that you cannot sign such a thing.