We demonstrate an integrated field-programmable nonvolatile memory technology on plastic, thus realizing a low-cost memory technology for systems on plastic such as RFID tags and sensors that require post-fabrication encoding with unique ID numbers. The crossbar memory array is integrated with steering diodes for every memory element, thus ensuring excellent addressability and scalability to large array sizes. Pentacene-aluminum schottky diodes were combined with a polyvinylphenol (PVP) dielectric to create field programmable nonvolatile memory crossbar arrays on a flexible PEN substrate. Our devices show high programmed/unprogrammed current margins (up to 10,000) at read voltages of 6V. Programming voltages are >20V, providing excellent read-write margin.