In 1996, the total in-hospital charges for the primary treatment of women with breast cancer with a modified radical mastectomy averaged $10,000 throughout the United States. The total charge (hospital plus physician’s fees) varied by 95% between the high charge reported in New York ($12,690) and the low charge in Michigan ($6,510). The hospital portion of the bill averaged 65% of the total and ranged from 51% in New York to 74% in Virginia. The average length of stay for these women was 2.39 days and ranged from 3.18 days in New York to 1.69 and 1.66 days in Washington and Arizona, respectively. The average charge for a partial mastectomy was $8,760, with notable variations between states. The Texas total charge was the highest ($12,890, some 47% above the US norm) and more than twice the low charge in Ohio ($6,080, 31% below the US average). The physicians’ charges averaged $3,330 for the country as a whole and accounted for 38% of the bill. This proportion ranged from 46% of the total in New York to 70% in Indiana and Colorado. The average length of hospitalization for a partial mastectomy was 1.84 days. On average, women remained in the hospital for the longest time in New Jersey (2.78 days) and for the shortest time in Oregon and Massachusetts (1.40 days and 1.45 days, respectively).[ONCOLOGY 12(6):889-902, 1998]