You will be held liable if you co-sign or sign as a guarantor for any medical bill. If the medical provider asks you to sign a document that says you agree to accept financial responsibility, then you need to decline or only sign in a limited capacity.  What I mean by this is if you are appointed as a power of attorney, make sure that you add a notation after your signature that reads "acting as power of attorney for____."  This will make it clear that you are not signing in a personal capacity, but rather in your capacity as a power of attorney, executor, or whatever other capacity that you assume.