The objective was to compare the effects of drying method on starch digestibility in corn silage (CS) using in situ (IS) and in vitro (IV) techniques. Three CS were selected with soluble protein ranging from 34.6 to 64.1%CP and split into 2 fractions. One fraction was dried via microwave (M) and the other was dried in an oven (O). Both fractions were ground to 4mm and 0.5g was weighed into IV flasks or 5 × 5 cm Dacron bags in triplicate. Blended ruminal fluid from 3 steers fed a diet of 30% starch in DM was used in a modified Goering and Van Soest (1970) IV method to measure starch digestibility after 3, 7 and 12h. Dacron bags were soaked in warm water for 10 min, then placed into the rumen immediately before feeding. Bags were removed after 3, 7, and 12h of incubation, washed, and starch remaining was measured. The IV and IS measurements were performed on the same days using the same steers. There were no differences between O and M in DM (P = 0.48), aNDFom (P = 0.64), and starch (P = 0.29). Starch washout was higher for IS-O vs. IS-M (78.7 vs 9.05%, respectively, P < 0.001). After 3h, starch disappearance (SDP) for IS-O was higher than IS-M (81.0 vs. 65.4%, respectively, P < 0.0001) but lower for IV-O vs. IV-M (27.2 vs. 55.1%, respectively, P < 0.0001). By 7h, SDP for IS-O was lower than IS-M (84.9 vs. 88.3%, respectively, P < 0.0001) and IV-O was lower than IV-M (61.3 vs. 84.6%, respectively, P < 0.0001). At 12h, SDP for IS-O remained lower than IS-M (89.9 vs. 93.7%, respectively, P < 0.0001), and IV-O was lower than IV-M (83.6 vs. 92.7%, respectively, P < 0.0001). At 7h, range of SDP was wider for IV-O vs. IV-M (42.1 vs. 12.1 units, respectively) and for IS-O vs. IS-M (13.7 vs. 8.39 units, respectively). There was no difference in IV-O kd calculating it using one time point (7h) vs. 3 (P = 0.86), but it was different for IV-M (P < 0.0001). Calculating kd using 1 vs. 3 time points was different for both IS-O and IS-M (P < 0.0001). These data suggest that the oven-dried in vitro method at 7h is appropriate to measure starch digestibility because it has the widest range of values and no sample loss due to washout.