Yes AND no.
Your baby is moving and learning and experimenting with a lot of muscles. When your child first walks, his/her steps and foot positions can change almost daily. If he/ she stays on his/her toes at this stage, get them evaluated to rule out sensory disorders and/or muscle imbalances. More than likely, he/she will settle into a flat foot position but there are activities to improve this that a therapist can help you with.
If your baby has been walking for a few months and begins to tip toe walk, it is possible that he/she is practicing a new skill (which is an appropriate skill at that time). Watch to make sure it is not all of the time or getting worse. This would be a concern to ask for an evaluation by a therapist.
Check out my book My Baby Moves: Toddler Games, available HERE