In microbiome research, universal PCR primers amplify specific 16S rRNA gene regions prior to sequencing for taxonomic relative abundance quantification. Here, we assess whether sequencing of PCR duplicates biases quantification results by incorporating Unique Molecular Identifiers (UMI) into our library preparation protocol across a range of conditions including PCR starting amount, cycles, UMI lengths, and in triplicate vs. combined. Our results will inform whether UMIs should be incorporated into standard 16S protocols across the field.