The objective of this study was to analyze whether a delay in time from admission until surgical treatment increased the mortality rate for patients with a closed hip fracture. We used the day of the week of admission as an instrumental variable to pseudorandomize patients. We analyzed 18,209 Medicare recipients who were 65 years of age or older and had surgical treatment for a closed hip fracture. Patients for whom the delay between admission and surgery was 2 days or more had a 17% higher chance of dying by Day 30. Using instrumental variables analysis, we found a similar 15% increased risk of mortality in patients with delays until surgery of 2 or more days. Based on these results, we found that a delay of 2 or more days significantly increased the mortality rate. This suggests that delay to surgery independently affects mortality, therefore additional study on the effect of smaller delays on outcome is needed.