There are some differences between the outpatient and inpatient services offered by the hospitals. The inpatient services deal with services provided in the form of overnight care provided to the patients. These services can be under different care units depending upon the needs of the patients. Example of some of these care units can be long term care facility and the skilled nursing facilities. Contrary to it the outpatient services offered by the hospital constitute of emergency services performed in the emergency departments of the hospital. Besides the emergency services there is another care unit called the ‘ambulatory outpatient care unit’. In the patients are admitted as an outpatient but they do not stay overnight and go home the same day after they have been administered with the required medical procedure and treatment. Hospice and home health care also fall under the category of the outpatient services.
Since the services offered in the outpatient and the inpatient is different hence there is a difference in the coding process also. In case of an inpatient service the coding is done when the patient is discharged and the rules for the application of codes in the inpatient services are a bit different than in the outpatient services. The most major difference is that the outpatient services use the primary codes and the inpatienservices use the principal codes. Also in case of inpatient services the codes may be different at the time of admitting the patient and at the time of diagnosis. Example would be like code 789 is used as an admitting code for the severe abdominal pain and after diagnosis code 540 would be used for acute appendicitis.
In the inpatient coding the ICD codes are utilized whereas in the outpatient coding the CPT codes are utilized. Also contrary to as stated above