If you are interested in pursuing a Masters of Arts in Christian Apologetics, here are a few options. For the two best places for apologetics training, check out:
Biola University - Offering perhaps the best apologetics program available. Distance programs also available.
Southern Evangelical Seminary - Fully accredited resident and distance education programs at the undergraduate and graduate levels specializing in Apologetics.
Liberty University - Offering a PhD. in Theology & Apologetics.
For those who want to pursue studies via distance learning and lower cost, check out:
Columbia Evangelical Seminary - Masters of Arts in Apologetics strictly through distance learning. A mentor program working at your own pace and custom programs.
Veritas Evangelical Seminary - Masters of Arts in Apologetics and distance learning programs. Under the oversight of Norman Geisler and a strong apologetics faculty.
If you do not wish to pursue a degree but want to study apologetics in a structured way under the oversight of a mentor, consider a Certificate in Christian Apologetics through Institute of Biblical Defense. Also, see this list of various graduate, undergraduate and non-accredited Christian apologetics training courses.
Please comment below with further resources, as there are more than just these.