Is the POA for a parent legally responsible for costs of nursing home care?

I was POA over my dad, he went into a nursing home and I was never responsible for one penny of his care.

Good Morning Lovingmom, I just went through this and sought advice from legal counsel as well as the Administrator of the Nursing Home. The answer is YES and NO.
NO- you are not responsible for any bills incurred by the person you have POA for when you sign for them to enter Nursing Home
UNLESS
it is deemed that you mismanaged that person's finances by spending their money on non-essential items while bills are outstanding.
Documentation will be your best friend, the best advice I got was to never pay out any monies without a bill in your hand, and in every decision you make - think of how your reasoning would sound in court. We were advised to not "loan" any money to Mother In Law for anything, we should pay for everything directly from her account. That way you don't have monies going to you which will raise red flags down the road, even if you fronted the money to begin with.
When she came to our house to live afterwards, we drew up a lease with her. We barely afford ourselves (I'm not working due to chemo) and to offset extra food ($800/month just for her in specialty foods) we had to put it in writing and I'm so glad we did, she is already telling people she is loaning us or we are stealing this $ every month.
Please check with the Administrator at the facility you are using, the rules may be different in your area.
Best of Health and bless you for caregiving

Thanks! This is helpful to know.