Is it time to move my Mom from our home into facility? 90 with CHF, atrial fib, stage 3 renal disease, UTI's and dementia. Almost 5 years.

Sorry, but when in rehab Medicare only pays 50%* after 20 days up to 100 days if Medicare feels the need for 100. A supplimental may pay the 50% balance, partial or not at all. If she hits a plateau or doesn't progress she will be discharged.

If Mom has no money other than SS and/or a pension, you will need to apply for Medicaid. If the facility has Skilled nursing but does not take Medicaid you can move her from that one to another when her rehab is done. You can have her evaluated for 24/7 while in rehab. If then you feel a SNF is where Mom needs to be then start the Medicaid application now.

*the only time Medicare pays 80% is on Dr. Visits, hospital stays, and some other things.

With the conditions you list she may qualify for Hospice.
You should begin the application process for Medicaid.
This is where Hospice might help. They have Social Workers that might be able to help with the application and bridging any gap there might be before Medicaid kicks in.
If your house or her house is not set up to accomodate her safely then it would be time to look into Skilled Nursing facility or Memory Care.
You could also talk to the Social Worker where she is currently in rehab, they may also be able to help.

Is she in rehab right now? It sounds like she has a lot of serious issues. It might be time for her to go into a nursing home that takes Medicaid, assuming she does not have any savings. My MIL is in one like this and is getting good PT as she recovers from her broken ankle.

It may not be a safe discharge for her to go back to your home. Wherever she is now can help you find an appropriate setting for her and transfer her there. I would reach out to them today and get the conversation started.

I'm not sure how bad her overall condition is, but is she ready for or close to a hospice evaluation?