I see those occasionally - it's usually for an "assisted living" arrangement where the resident is somewhat independent, but nursing care is available if needed.  The resident pays monthly "rent" also.  The facility gives the resident a lengthy memo saying what percentage (to four decimal points) of its  expenses are for medically-related costs, and then cites two methods of using that number based on some Tax Court or IRS rulings.  Ask the facility about what to expect as documentation, and when to expect it.  ($400K is probably for a couple?)