In the past few weeks I have been asked to reattune two people to Reiki 2.
On both occasions I have advised that this was not necessary as once you are attuned you stay that way for life (unless you block the attunement in some way while it is being done - even then you can open to it later on when you decide to). 
However you may drift away from the practice and become less sensitive to reiki and feel like you have lost the connection.
If you feel like this is you, or need inner guidance here is a meditation to do when ever you can (in the bath, last thing at night, during meditation ect) to enable to to connect again:-
Invoke your reiki guides with this prayer - 'By Divine highest order I call forth Beings of the highest love and the highest light to help me in this healing to connect to Reiki'.  Close your eyes and place one hand on your heart and one on your solar plexus or directly above, draw the power symbol if you practice this.  Feel what is happening for you right now without trying to think of what should be happening or expecting a certain result.  Notice how your hand feel, how your heart and solar plexus feels and even if you think nothing is happening stay with it.  Focus on the present, listening to and feeling your breath will help you with this.  Be patient and enjoy this process of exploration.  Be grateful that you are returning to Reiki and welcome it back in to your life.  Commit yourself to practicing again.  Repeat this exercise as often as you can to re-tune and fine tune your Reiki pratice yourself!
If you feel you would like to take your Reiki to the next level with an attunement please let me know and I would be delighted to do a Private Attunement Day with you, please see details in the Reiki section. 

It is an exciting time at the moment.  I am starting to practice Reiki from Henrietta's clinic on Fridays from the 26th March.  I am looking forward to being part of such a lovely place and all the new faces and opportunities it will bring.