Purpose: The functional scope of general hospitals varies with bed capacity, yet current facility standards in South Korea tend to treat general hospitals as a single category, potentially failing to reflect differences in scale and function. This study aimed to empirically examine differences in medical resource composition by bed-scale group and to identify long-term trends in their change, with a view to informing facility planning standards. Methods: Data were drawn from Health Insurance Review and Assessment Service (HIRA) records, reconstructed by 100-bed intervals for general hospitals and tertiary hospitals from 2014 to 2026. In addition to group-level mean trends over time, distributional statistics — median, interquartile range (IQR), and coefficient of variation (CV) — were calculated to assess within-group variation among hospitals. Results: Medical resources including specialist physicians, critical care beds, and diagnostic equipment showed a general tendency to increase across most bed-scale groups, suggesting a possible trend toward functional upgrading. Resources tended to grow in a stepwise rather than proportional pattern, with more pronounced differences at thresholds of approximately 300, 500, 800, and 1,000 beds. Within-group variation was also considerable: CVs reached 40–50% for specialist physicians and 34–75% for adult ICU beds in the 200–399-bed range, indicating that hospitals within the same bed-scale group may differ substantially in their actual resource composition. Implications: These findings suggest that bed capacity alone may have limited value for estimating medical resource levels at the individual hospital level. Current standards tend to be calibrated to medium-to-large hospitals, potentially posing practical difficulties for hospitals under 300 beds, which constitute the majority of general hospitals in Korea. Differentiated guideline frameworks applicable selectively according to hospital scale and medical characteristics may warrant consideration in future standard-setting discussions.