A coupler and a method for installing an instrumentation line, such as fiber optic cable, into a wellbore. The coupler places upper and lower instrumentation lines in communication with one another downhole to form a single line. The coupler comprises a landing tool and a stinger that lands on the landing tool, thereby placing the upper and the lower instrumentation lines in communication. The landing tool is run into the wellbore at the lower end of a tubular, such as production tubing. The upper instrumentation line affixes to the tubing and landing tool and extends to the surface. The lower instrumentation line affixes along the stinger. In this manner, the lower instrumentation line may be installed after expansion of a well screen or liner and may be later removed from the wellbore prior to well workover procedures without pulling the production string.