There are no specific health conditions that qualify someone for Medicaid coverage of long-term nursing home care. Instead, Medicaid looks at whether nursing-home level care on a daily basis is "medically necessary" for the person applying for coverage. This is determined by a person's overall physical and mental capacities, not by any specific illness or condition. One of the ways Medicaid judges this medically necessity is by looking at the person's ability to perform -- without assistance -- what are called "the activities of daily living" (ADLs), which include bathing, walking, dressing, eating, using the toilet, and getting in and out of bed or a chair. Depending on the rules of the specific state Medicaid program, a person might need assistance with two or three of these ADLs in order to qualify for long-term nursing home coverage.
In making its decision, Medicaid will not just take your word, or that of other family members, about your mother's condition and need for care. Nor will Medicaid simply accept the judgment of the nursing home itself, although it will certainly consider the level of care it has been providing your mother over the previous years before her application for Medicaid coverage. (They won't just take the nursing home's word because the nursing home has a financial interest in being paid for care.) Instead, Medicaid will require an order from your mother's regular doctor stating that nursing home level care is a medical necessity for her.
When the time gets closer that your mother's money will run out and she'll apply for Medicaid coverage, get in touch with her regular doctor and let him or her know that this issue of "medical necessity" for nursing home care will be coming up, asking whether the doctor is ready and willing to provide the necessary order for this level of care. If the doctor has not seen enough of your mother recently in order to make such a decision, you may want to arrange for her to be examined by the doctor so that the doctor has enough recent information to provide the necessary medical order.