Length of stay for the inpatient hospitalization (LOS_IP) is calculated by subtracting the admission date (ADATE) from the discharge date (DDATE). Same-day stays are therefore coded as 0.

LOS_IP is missing (.) if the length of stay cannot be calculated. LOS_IP is invalid (.A) if it is greater than the maximum value allowed during HCUP processing. LOS is inconsistent (.C) if LOS is negative, excessively long, or inpatient charges per day are unjustifiably low or high. Editing of LOS_IP is consistent with the editing of length of stay on the SID.