Small modular reactors (SMRs) are being developed to provide clean electricity and support new applications for nuclear energy such as hydrogen production, industrial heat generation, and water desalination. SMRs also incorporate improved passive safety features, support load-following operations and extended refueling cycles, and provide spent fuel management solutions. As with any other type of nuclear power plant (NPP), the safe and reliable operation of SMRs depends on accurate and timely measurement of the primary system temperature, pressure, level, flow, and neutron flux. The performance of instrumentation and control (I&C) sensors that make these measurements must be testable and verified prior to initial startup, during operation, and/or during subsequent refueling outages. For traditional large scale reactors, in-situ or on-line test methods for measuring the static and dynamic performance of I&C sensors such as thermocouples, resistance temperature detectors (RTDs), and pressure transmitters are well-established. However, unique characteristics of SMRs, such as the integral pressure vessel design and natural circulation core cooling, require special consideration with respect to I&C sensor performance testing. That is, new methods may have to be developed or existing methods adapted to meet the I&C testing needs of SMRs. This paper presents the results of on-going research conducted by the authors to address the challenges associated with I&C sensor testing in SMRs. This effort is supported by research grants from the U.S. Department of Energy (DOE). This research includes the validation of existing methods and development of new methods for verifying the performance of I&C sensors before and after they are installed in the plant. In addition, I&C maintenance and test procedures will be written to be used by SMR plant personnel to verify that installed safety-related sensors meet the plant technical specifications for static (calibration) and dynamic (response time) performance at normal operating conditions. The efforts described in this paper will directly support the timely deployment of the NuScale Power Module, which is at the forefront of SMR development in the United States, as early as 2026.