A catheter assembly with segmented or step-wise deployment stabilization system includes a base or handle, puncture needle extending from the handle, and a deployment mechanism or mechanisms to selectively extend from the distal end of the needle for first length a hollow stabilizing component and as a second step to a second further length a stabilizing guide wire element. The needle will gain sub-dermal access to the patient to the intended position for deployment of a catheter. Hollow stabilizing component provides for a first additional guide and support for a catheter sheath from the distal end of the needle. The stabilizing wire element provides additional length, guide and support for the catheter sheath. The hollow stabilizing component has some degree of flexibility as does the guide wire to minimize chance of damage to surrounding tissue. The user can feel resistance and have the opportunity to retract either component and attempt redeployment without a retraction of the puncture needle and a second poke of the patient's skin. In the example for peripheral venous catheterization, the system reduces the probability of blood vessel puncture. The deployment mechanism can have a guiding system which ensures the proper sequence of deployment.