Abstract: A method for identification of a urine sample and for verification of a donor identity of a urine drug testing sample to rule out adulteration or substitution in urine drug testing, comprising: preparing a urine drug testing sample and a reference sample with a confirmed donor identity, extracting or releasing DNA from the urine drug testing sample and the reference sample, amplifying and genotyping the extracted or released DNA from both samples; analyzing and comparing the DNA from the urine drug testing sample to the DNA from the reference sample; and based upon the analysis and comparison results, determining and reporting a match or mismatch between a donor identity of the urine drug testing sample and the donor identity of the reference sample. The donor identity of the reference sample is confirmed to be a person providing the urine drug testing sample.