Mod tech is agreed to be comprised of Cyber, Bio and Nano modifications with mixed mods possible.
Cyber Mods can occasionally be rejected due to an allergic reaction, a condition which is know as Cybernetic Incompatibility Syndrome or CIS. Despite the slight risk of CIS, users often times chose cyber mods over Bio due to the lower cost easier acquisition and ease of repair. Cyber mods are unfortunatley very obvious and easy targets for corporate trademark repos.
Biomods come with their own sets of risks which tend to be mild until users begin to add more and more bio mods to their systems. At this point genetic drift, cancer and autoimmune rejection/disorders are all possible. Often those who want significant bio modification must undergo a body transplant to side step systemic rejection. However many users still prefer Bio mods due to their ease of care prior to genetic problems and the ability to keep the majority of their modifications secret.
Mixed mods and nano mods share disadvantages of their component mods I.E. nano mods can be subject to CIS and bio+cyber can still experience genetic drift. That said such exotic modifications are able to produce results that are not possible with purely Bio or cyber.
For listings of mod tech see Human Enhancement