Productivity and nutritive value of stockpiled bermudagrass are influenced by N fertilization and environmental conditions. Intake of forage DM and DE are highly correlated with kinetics of NDF digestion; yet, NDF digestion kinetics of stockpiled bermudagrass have not been extensively investigated. Therefore, a study was conducted to evaluate effects of N fertilization and seasonal changes in nutritive value on NDF digestion kinetics from stockpiled bermudagrass. Replicate (n = 2) pastures of Tifton 85 bermudagrass were cut on Aug 1 and fertilized with 56 (56N), 112 (112N) or 168 (168N) kg N/ha. Stockpiled forage was sampled monthly beginning on Oct 24, 2012 and analyzed for kinetic parameters of NDF digestion using in vitro fermentation. Undigested NDF residues were recovered at 3, 6, 9, 12, 18, 24, 48 and 72 h of incubation. Potential extent of NDF digestion was assumed complete at 72 h. Rates of NDF digestion were determined by least-squares regression of ln % potentially digestible NDF remaining vs. time; solution of the first-order kinetic equation to equal 100% potentially digestible NDF remaining yielded estimates of lag time. Data were analyzed as a completely randomized design using the PROC MIXED procedure of SAS 9.2. No N fertilization × sampling date interactions (P > 0.05) were observed for any kinetic parameters measured. Potential extent of NDF digestion was greatest (P < 0.05) in Oct (75.6%), least (P < 0.05) in Jan (47.8%), and intermediate but not different (P > 0.05) between Nov (61.1%) and Dec (59.0%). Potential extent of NDF digestion was greatest (P < 0.05) for 168N (63.2%) and least (P < 0.05) for 56N (58.8%). Rates of NDF digestion were not affected (P > 0.05) by N fertilization, but were greater (P < 0.05) in Oct (0.069 h⁻¹) and Nov (0.068 h⁻¹) than in Jan (0.063 h⁻¹). Lag time was less (P < 0.05) for the 168N (7.3 h) than 56N (9.1 h) and 112N (8.8 h) treatments. Lag time was least (P < 0.05) in Oct (6.0 h), intermediate (P < 0.05) in Jan (7.8 h), and greatest but not different (P > 0.05) between Nov (10.5 h) and Dec (9.4 h). Potential extent of NDF digestion was the kinetic parameter most affected by N fertilization and seasonal changes in stockpiled Tifton 85 bermudagrass.