Based on the context and the answer, generate a question. 

Context: My sister was inbetween health insurances in her job , and of course , needed emergency gall bladder surgery . The surgeon wanted $ 4000 , they agreed on $ 2000 . She had the surgery , and when she told me the cost , as a Medical Biller I advised her that ins co have fee schedules and would pay between $ 500 and $ 900 depending on the co.

Answer:

They feel financially tight amid a need for surgery .



Why may the sister and her family be so stressed out ?