One of the most critical elements in a performance evaluation (PE) program for environmental and radiobioassay radioactivity measurements is the traceability of PE materials to the national standards. The requirements and criteria for the production of traceable PE materials have been defined by ANSI N42.22 and ANSI N13.30 standards. It is important to note that use of traceable source materials does not necessarily ensure the traceability of subsequently derived PE materials unless verification measurements are in concert with the preparation processes.  This poster describes the protocol currently used in the NIST Radiochemistry Intercomparison Program (NRIP) for the preparation and verification of air filter, acidified water, spiked soil, synthetic urine, and synthetic fecal PE materials for low-level radioactivity measurements. The process involves gravimetric dilutions of primary standard reference materials, gravimetric addition of activity to sample matrices, and subsequent verification measurements linked through an unbroken chain of comparisons. The statistical results from t-tests, box plots, and normal probability tests also suggested that traceability of radionuclides in the PE materials to their primary standards can be verified within 1%, with an overall precision better than 3%. The poster will also examine the results obtained from the PE studies over the past three years.