Junction diodes fabricated in standard CMOS logic processes can be used as program selectors for One-Time Programmable (OTP) devices, such as electrical fuse, contact/via fuse, contact/via anti-fuse, or gate-oxide breakdown anti-fuse, etc. The OTP device has an OTP element coupled to a diode in a memory cell. The diode can be constructed by P+ and N+ active regions on an N well as the P and N terminals of the diode. By applying a high voltage to the P terminal of a diode and switching the N terminal of a diode to a low voltage for suitable duration of time, a current flows through an OTP element in series with the program selector may change the resistance state. The P+ active region of the diode can be isolated from the N+ active region in the N well by using dummy MOS gate, SBL, or STI/LOCOS isolations. If the resistive element is an interconnect fuse based on CMOS gate material, the resistive element can be coupled to the P+ active region by an abutted contact such that the element, active region, and metal are connected in a single rectangular contact.