A medical access device provides needleless access to patient fluid lines such as intravascular catheters. A preformed crimp ring is attached around a septum and the top end of the housing of the medical access device. The crimp ring is configured to hold the septum in place. The septum provides access for a tubular portion of a medical device such as a male luer taper of a syringe. The crimp ring is then attached by mechanical attachment and/or chemical adhesion to the housing to minimize axial and rotational movement between the septum and the housing.