Historically, reaching this stage takes anywhere from three to ten years. The defense must be completed within four years of reaching candidacy. Once you have successfully defended your thesis, you will be awarded a diploma the following May. In the past few years, the distribution of years to graduation is as follows:
| 3 years | 1 | 8 years | 3 | |
| 4 years | 0 | 8.5 years | 1 | |
| 5 years | 9 | 9 years | 3 | |
| 6 years | 9 | 10 years | 1 | |
| 7 years | 4 | 11 years | 0 | |
| 7.5 years | 1 | 12 years | 2 |
The 7.5 and 8.5 years were students who began in January, rather than August. Fortunately, the number of years until graduation seems to be decreasing for newer students. No one in the department has ever failed a thesis defense. However, revision or addition to the thesis may be required.