Hi Audrey - depending on the package line-up you have may require to get a second box. For example, if you have a digital tiered package with a movie channel, i.e., HBO, Starz, etc,. for you to see the same on the second TV well yep you will need an additional box. Note that the first box comes with your existing package.
If you are just interested in getting cable, then i suggest a DTA which can be received by contacting us. If you would like more information email
we_can_help@cable.comcast.com and we will offer all answers needed. Even if needed arrange for a box or the DTA to be delivered to you.