This investigation provides internal consistency reliabilities for the Wechsler Memory Scale--Fourth Edition (WMS-IV) subtest and index discrepancy scores using the standardization samples of the Adult and Older Adult batteries. Subtest reliabilities ranged from 0.00 to 0.93 for Adults and 0.25 to 0.94 for Older Adults. Three of 91 Adult coefficients and three of 24 Older Adult coefficients reached the recommended level ([greater than or equal to] 0.90). Index reliabilities ranged from 0.46 to 0.94 for 100 Adult Battery comparisons and 0.19 to 93 for 36 Older Adult Battery comparisons. Each battery had 10 coefficients [greater than or equal to] 0.90. Ability-memory discrepancies were reported using WAIS-IV VCI, PRI, WMI, and GAI as intelligence standards. Ability-memory comparisons for the Adult Battery ranged from 0.82 to 0.93 with 12 of 20 comparisons [greater than or equal to] 0.90; Older Adult Battery reliabilities ranged from 0.85 to 0.94 with six of 16 comparisons [greater than or equal to] 0.90. In terms of discrepancy score reliabilities, the WMS-IV represents a marked improvement over the WMS-III.