Abstract Introduction/Objective Our multi-hospital system recently adopted uniform use of 2 decimal places for reporting of creatinine (mg/dL), in accordance with NIH guidelines. Surprisingly, this change in patient reports fostered complaints from clinicians. Use of 2 decimal places is both analytically appropriate and reduces imprecision in calculations of estimated glomerular filtration rate (eGFR). Primary literature is devoid, however, of a delineation of the scale of the effect of using 1 vs. 2 decimal places to calculate eGFR. We examined this effect for both the Modified Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR equations. Methods/Case Report Creatinine is an input to a single multiplicative creatinine factor in eGFR calculations for MDRD and CKD-EPI equations. We calculated the creatinine factor for these equations for creatinine=0.6-10 mg/dL, and evaluated the % difference in this factor when using increments of 0.1 mg/dL (1 decimal place) compared to increments of 0.1±0.05 mg/dL (viz., the 2 decimal place boundaries of a rounded 1 decimal place report). The observed % differences reflect those that would be observed in associated eGFR results. Results (if a Case Study enter NA) Input of 1 vs. 2 decimal places for creatinine in eGFR calculations, using either MDRD or CKD-EPI, produces differences in eGFR of greater than ±5% only for creatinine <1.2 mg/dL, and greater than ±10% only for creatinine <0.6 mg/dL (MDRD only). These ranges for creatinine are within or near-to reference ranges for both males (0.7-1.4 mg/dL) and females (0.6-1.0 mg/dL), and encompass approximately 70% of all patient reports for our patient population. For comparison, eGFR has a 95% confidence interval of approximately ±30% across all eGFR’s. Conclusion The ±5% reduction in precision in eGFR for such a large fraction of results by use of only 1 decimal place for creatinine was deemed unwarranted. Clinician complaints were handled by one-to-one discussions.