What’s the difference between Qigong and Tai Chi?
Both have the art of internally guiding the qi at their core. Tai Chi weaves this into longer and more elaborate choreography of movements, whereas in Qigong the movements (repeated to cultivate qi) can be slight or few, depending on the form, but the development of profound inner somatic awareness is strong. I do not teach Tai Chi on its own. The form I have studied is Tai Chi Qigong Shibashi, a deliberate combination of aspects of both practices. Read more.
Great Grandmaster Kellen Chia of the Tai Chi Society writes
‘While low-level Tai Chi is solely a physical exercise, at higher level it transcends into a Qigong discipline. In other words, if there is no Qigong then there is no real Tai Chi — if one cannot master the internal skill of Qigong, then one will not be able to master Tai Chi. If one has mastered Qigong internal skill, then it does not necessarily mean that one is capable of mastering Tai Chi, but if one has mastered real Tai Chi then one has also mastered Qigong internal skill.
The essence of Qigong is critical for Tai Chi, in that it gives one real power throughout the practice of Tai Chi.’
 Chia, Kellen, ‘The Difference Between Tai Chi and Qigong” 23 Oct 2011, online at http://www.taichisociety.net/difference-between-tai-chi-qigong.html