A catheter system, comprising: a catheter adapter, comprising a distal end, a proximal end, and a wall forming a lumen; a catheter extending distally from the distal end of the catheter adapter; a needle assembly coupled to the catheter adapter, the needle assembly comprising: an introducer needle, comprising a distal tip and a bump feature, wherein the distal tip is disposed distal to the catheter in a first position; a housing, comprising: a distal opening; a proximal opening, wherein a diameter of the proximal opening is less than an outer diameter of the bump feature, wherein the introducer needle extends through the distal opening and the proximal opening; and a support ledge lateral to the introducer needle; a needle tip shield, comprising a contact surface; and a compression element disposed at least partially around the housing and the needle tip shield, wherein the contact surface is aligned with the support ledge and the compression element presses the contact surface against the support ledge, wherein in response to withdrawal of the distal tip proximally from the first position to a second position, the bump feature contacts the proximal opening, wherein in response to withdrawal of the distal tip proximally from the second position to a third position, the housing moves proximally and the contact surface is unaligned with the support ledge such that the compression element moves the housing and the needle tip shield together and the needle tip shield blocks the distal opening. a catheter adapter, comprising a distal end, a proximal end, and a wall forming a lumen; a catheter extending distally from the distal end of the catheter adapter; a needle assembly coupled to the catheter adapter, the needle assembly comprising: an introducer needle, comprising a distal tip and a bump feature, wherein the distal tip is disposed distal to the catheter in a first position; a housing, comprising: a distal opening; a proximal opening, wherein a diameter of the proximal opening is less than an outer diameter of the bump feature, wherein the introducer needle extends through the distal opening and the proximal opening; and a support ledge lateral to the introducer needle; a needle tip shield, comprising a contact surface; and a compression element disposed at least partially around the housing and the needle tip shield, wherein the contact surface is aligned with the support ledge and the compression element presses the contact surface against the support ledge, wherein in response to withdrawal of the distal tip proximally from the first position to a second position, the bump feature contacts the proximal opening, wherein in response to withdrawal of the distal tip proximally from the second position to a third position, the housing moves proximally and the contact surface is unaligned with the support ledge such that the compression element moves the housing and the needle tip shield together and the needle tip shield blocks the distal opening. an introducer needle, comprising a distal tip and a bump feature, wherein the distal tip is disposed distal to the catheter in a first position; a housing, comprising: a distal opening; a proximal opening, wherein a diameter of the proximal opening is less than an outer diameter of the bump feature, wherein the introducer needle extends through the distal opening and the proximal opening; and a support ledge lateral to the introducer needle; a distal opening; a proximal opening, wherein a diameter of the proximal opening is less than an outer diameter of the bump feature, wherein the introducer needle extends through the distal opening and the proximal opening; and a support ledge lateral to the introducer needle; a needle tip shield, comprising a contact surface; and a compression element disposed at least partially around the housing and the needle tip shield, wherein the contact surface is aligned with the support ledge and the compression element presses the contact surface against the support ledge, wherein in response to withdrawal of the distal tip proximally from the first position to a second position, the bump feature contacts the proximal opening, wherein in response to withdrawal of the distal tip proximally from the second position to a third position, the housing moves proximally and the contact surface is unaligned with the support ledge such that the compression element moves the housing and the needle tip shield together and the needle tip shield blocks the distal opening.