This paper explores the viability and stability of compact stellar objects characterized by anisotropic matter in the framework of the $f(Q, T)$ theory, where $Q$ denotes non-metricity and $T$ represents the trace of the energy-momentum tensor. The authors consider a specific model of this theory to derive explicit expressions for the field equations governing the behavior of matter and geometry. The Karmarkar condition is employed to assess the configuration of static spherically symmetric structures, and unknown constants in the metric potentials are determined through matching conditions of the interior and exterior spacetimes. Various physical quantities such as fluid parameters, energy constraints, equation of state parameters, mass, compactness, and redshift are graphically analyzed to evaluate the viability of the compact stars. The Tolman-Oppenheimer-Volkoff equation is used to examine the equilibrium state of the stellar models, and the stability of the proposed compact stars is investigated through sound speed and adiabatic index methods. The study concludes that the proposed compact stars are viable and stable, as all the required conditions are satisfied.This paper explores the viability and stability of compact stellar objects characterized by anisotropic matter in the framework of the $f(Q, T)$ theory, where $Q$ denotes non-metricity and $T$ represents the trace of the energy-momentum tensor. The authors consider a specific model of this theory to derive explicit expressions for the field equations governing the behavior of matter and geometry. The Karmarkar condition is employed to assess the configuration of static spherically symmetric structures, and unknown constants in the metric potentials are determined through matching conditions of the interior and exterior spacetimes. Various physical quantities such as fluid parameters, energy constraints, equation of state parameters, mass, compactness, and redshift are graphically analyzed to evaluate the viability of the compact stars. The Tolman-Oppenheimer-Volkoff equation is used to examine the equilibrium state of the stellar models, and the stability of the proposed compact stars is investigated through sound speed and adiabatic index methods. The study concludes that the proposed compact stars are viable and stable, as all the required conditions are satisfied.