Home care can refer to health care provided in the home by health care professionals (often referred to as home health care or formal care) or by family and friends (informal care). Estimates for the US indicate that most home care is of the informal variety with families and friends providing substantial amounts of care, including very high tech kinds of care as well as simpler assistance with bathing or dressing. For formal care, the health care professionals most often involved are nurses followed by physical therapists and home care aides. Other health care providers include respiratory and occupational therapists, medical social workers and mental health workers. Physicians may perform home visits, also. In the US, home health care is generally paid for by private employer-sponsored health insurance or public payers (Medicare and Medicaid).