Is this a stipulation of the Medicare program or something the hospital system itself is requiring?

I currently work with an in-home care company. We deal with the medical assistance program in our state. We do not deal with the medicare program as our licensing would need to be different so my question is: Recently my in-laws and a friends mom were told by the local hospital that if they receive home care from them, they cannot even go out to eat at a restaurant with family or a friend or they will lose their in home service. I do not understand that "rule". Is this a stipulation of the Medicare program or something the hospital system itself is requiring? Either way we are creating home bound seniors instead of seniors that receive some in-home services so they can remain involved in their communities as much as possible.