A programmable resistor includes a variety of taps. Selection of any of a variety of tap combinations establishes a path through which current will flow, thus, setting the resistance value of the programmable resistor. The programmable resistor minimizes the effects of parasitic end boundary resistances, R.sub.end/w, between contacts and resistive areas by limiting the contribution of the end boundary resistances to 2R.sub.end/w, regardless of the programmed tap combination. By fabricating a contiguous region of impedance material, only the R.sub.end/w end boundary resistances associated with selected taps affect the value of the programmed resistance. A notched tap structure provides predictability of the resistance value of each tap combination. Taps are narrowed to form a notch which establishes a well-defined current flow path, thus providing the resistance predictability. Additionally, notches also allow for a wider contact-resistive area end boundary, thus, further minimizing the parasitic effect of R.sub.end.