Structures for testing a field effect-transistor or Kelvin field-effect transistor, and methods of forming a structure for testing a field-effect transistor or Kelvin field-effect transistor. The structure includes a test pad, a device-under-testing having one or more source/drain regions, and a metallization level arranged over the device-under-testing. The metallization level includes one or more interconnect lines that are connected with the test pad. One or more contacts, which are arranged between the metallization level and the device-under-testing, directly connect the one or more interconnect lines with the one or more source/drain regions.