A damaged land/ocean mask file (specifically, a several-gridbox shift to the east and south) has been discovered in IMERG V06A, which causes mis-identification of surface type along coasts in the Kalman filter computation.  While simple to correct, the change in the IMERG results requires shifting to a new sub-version.  As of May 22, the Early and Late Run files have the corrected land/ocean mask file and are labelled V06B.  The adjustment will be seen in the Early and Late data files starting June 1, when the next Kalman statistics are computed.  Final Run retrospective processing for V06B will begin shortly; more information will be forthcoming.