Can a home care company terminate services without any notice?

In the middle of your explanation is the comment about a possible workman's comp claim. I think your reason may be right there. If you are paying privately please make sure you are properly paying employer taxes etc. for later Medicaid eligibility. You also need a special rider on your homeowners insurance if you have people working in your home privately. If you are at the house, she is not being left unattended. You need to be sure that you have agreement in place for caregiving that protects mom, you and them. A claim from private caregiver injured in your home could bankrupt your mom.

Often when there is someone that requires full assist they want a Nurse or certified CNA to do the job. And that is 2 Nurses or 2 CNA's.
The cost gets to be pretty high.
At this point I think most Assisted living places will not take someone that is a 2 person assist or someone that needs "machines" like a Sit to Stand or a Hoyer lift to aid in transfer. These people are now placed in "Nursing Homes" rather than Assisted living or Memory Care facilities.
Sure costs a lot more for the family!
I am sure the Agency is going this route as well.
But that aside you deserve a reasonable answer as to why the termination and with no notice.
Just a thought but you might want to ask if they can refer you to another agency.

In our state, MN, Home Care agencies cannot drop someone immediately. They need to notify the family, and give 2 weeks notice to allow family to find Plan B. You should check with your state Ombudsman to find out the rules in your state. Or the Department of Health who oversees Home Care agencies.

I would start with a call to mom's dr and ring all the bells possible that mom is going to be without care because she doesn't have a lift.

Call APS and alert them to the fact that mom is a vulnerable elder who has no care due to the agency backing out?

I'm so sorry that you've been dropped without warning into this terribly stressful situation. I hope the suggestions people have made will help you to get things straightened out.

It does sound as though something - some regulation, some problem - suddenly dawned on the agency and their reaction was to run like the wind. That reaction was unprofessional and created the potential for risk. You may not have a contractual claim (depends what's in the contract) but you certainly do have grounds for a formal complaint. Find out who the agency's regulator/inspector is and write to them.

Nothing happened between them. The two who work 6 days a week have been with us for several months. I've spoken with them, and both cried. They're both coming tomorrow as private pay, but neither they nor I can do this long term.
Synopsis: Mama is max assist. They expressed concern for their employees and a possible workman's comp claim, and requested I ask Mama's primary doctor for a prescription for a Hoyer lift. I placed the call to her doctor, leaving a message. Shortly afterwards, the agency called back with a 'nevermind' attitude, and terminated service immediately. I would be somewhat ok IF they had given a few days notice so that I can hire another agency. I am her only family member able to be here, but I cannot lift her due to an injury to my hips, which they are very aware of. This feels a lot like abandonment of a vulnerable person since they are leaving her without care.

Folks are lifted in a Hoyer lift by lay caregivers at mom's memory care and they weigh a lot more than your mom

Call another agency immediately and get help in
If the two aides want to stay with your mom then refer them to the next agency - they all usually have their names out with more than one

Being left in the lurch by caregivers is a big hindrance to keeping loved ones at home

I agree that many things point to facility care. Seems you need a quick solution, a soon solution and a long-term solution all to be researched immediately.
Quick: find another licensed, bonded home care company to continue service.
Soon: find a way to get a Hoyer lift. Can her insurance help?
Long Run: Research facilities now. You might try seeking a social worker at your hospital, call your local Council on Aging to find help in seeking help. The COA membership costs $10.00 a year and they've been invaluable for me. Bless you!!

As an owner of a Home Service Agency - I would suggest contacting the Department of Health in your state. They can put you in contact with the office that would handle your inquiry. Each state is different. We are in Illinois and the mandate is that if we terminate an agreement, we are required to provide 7 days notice UNLESS it is a safety concern. This information should be spelled out clearly and concisely in the Service Agreement Form. Good luck.

Unfortunately it will be based on what is stated on your contract. However, it may be illegal to abandon the client without notice. I would report their actions to the Better Business Bureau.