This study is to find out changes in medical practice at a university hospital before and after covering intraocular lens (IOL) from the health insurance benefit. The coverage started on March 1, 1993 and a total of 596 cases who were discharged from July 1 to December 31, 1992 and 580 cases who were discharged from July 1 to December 31, 1993 were analyzed. Since the standard reimbursement scheme was changed from March 1, 1993, the charges for 1992 were transformed into 1993 scheme. Major findings are as follows: Average length of stay was statistically significantly decreased from 8.24 days in 1992 to 6.86 days in 1993. Charges except IOL has been statistically significantly decreased from 501,000 Won in 1992 to 444,000 Won in 1993. Charges for drugs and injection have been reduced. However, charge per day for them was not much different. This is due to decrease in length of stay. Charges for laboratory tests and radiologic examination were quite the same. Charges which are not covered by the insurance remained the same. The revenue of the hospital was reduced as expected. However, the hospital reduced the length of stay and increase the turnover rate In order to compensate the potential loss of revenue due to the difference of reimbursement between the out-of-pocket expense and the insurance coverage. By introducing the IOL benefit in the insurance, the insured pays less, hospital generates more revenue through shortening the hospital stay, and the total medical care cost becomes less nationwidely.