Question: What is the CPT code for Gastroccult (new waived test for detecting gastric occult blood)? New Mexico Subscriber Answer: The SmithKline Gastroccult test is a rapid screening test to detect the presence of gastric occult blood. The corresponding CPT code is 82273-QW (Blood, occult, by peroxidase activity, qualitative; other sources). If you are not being reimbursed for this test, then the problem may be that you are not adding the -QW modifier onto the code. This modifier signifies that the test is a CLIA-waived test.