The Survey of Perceived Organizational Support (SPOS) is a unidimensional measure of the general belief held by an employee that the organization is committed to him or her, values his or her continued membership, and is generally concerned about the employee's well-being. In the interest of efficiency, researchers are often compelled to use a minimum number of SPOS items in their studies. This study reports on a reliability generalization across 62 published studies using the SPOS. Findings suggest that number of SPOS items and mean age of the sample are statistically significant in the relationship to reliability estimates. Additionally, mean age accounted for significant variance in internal consistency estimates over and above the number of items used.