My mother was being transported by an agency caregiver. Auto accident occurred causing mother to sustain broken back. Is agency liable?

Do not sign anything until you see an attorney

The insurance company of the person at fault will be responsible. As freqflyer wrote, be sure your mother doesn't sign anything. They will try to rush it through, often offering some small settlement to get someone to sign. Tell them that she will sign after all the treatment and bills come through. I think it should be illegal for adjusters to try to settle in cases like this, but it isn't. Once she settles, she cannot claim further damages.

The Caregiver wasn't at fault, thus the Agency wouldn't be liable.   Sounds like the driver-at-fault's auto insurance wants to settle quickly.   Make sure your Mom doesn't sign anything regarding this accident.

Since Mom needs to have back surgery, I would hire an accident claim Attorney to see what he/she can do, and what type of settlement your Mom can get.