The objective of this study was to analyze prescription decisions for family practice (FP) patients with Diabetes mellitus type 2 (DM2) using the case of the incretin mimetics Dipeptidyl peptidase-4 (DDP-4) inhibitors and Glucagon-like peptide-1 (GLP-1) agonists dependent on patients’ health insurance status (statutory or private) in Germany. This evidence concerns the gene GCG and diabetes mellitus.