Inpatient coding rules and their implementation vary according to the extent of detail in a specific medical case. However, there are a few guidelines that are basic and are essential in all coding practices.

These are:

1.When coding, for greater accuracy, use both the alphabetic index and the tabular list to ensure that no errors are encountered.

2.Always assign all the five digit ICD codes if they are available and use four and three digit codes only when no other information is available. When coding diagnostic and procedure codes, try to be as specific as possible under the circumstances and so use as many codes as possible.

3. Only use the NOS(other) and NEC (Unspecified) codes when the information given does not allow further coding and so there is no provision of more specific details. One may refer back and forth between the alphabetic and the tabular list to be more certain of the coding instead of using the above codes.

4.If a condition is described as both acute and chronic, use sub-entries and enter the subacute code first. Only entering one of the two will be presenting incomplete information.

5.Avoid using multiple coding if there is a combination code that includes both medical conditions or gives the condition and the secondary condition that comes as a result or as a manifestation of the first condition.

6.When not possibly to use the combination code, use multiple codes by referring to both the alphabetical and the tabular references. Avoid using multiple coding too much or giving irrelevant information.

7.When coding late effects such as the manifestations that occur long after the acute phase of an illness is over, use both the late effect code and the cause of the late effect. Sequence the residual condition first and then the cause of the late effect. Never use the code for the acute phase of the illness when coding the late effect of the illness.

8.When coding conditions that were termed as possible or probable, suspected, likely or questionable by the time of discharge, code as if the condition was really verified.

9.If there is an imminent or threatened condition that was speculated as probable, if it happened by the time of discharge, code it as confirmed diagnosis. If it did not happen, list it as impending or threatened by referring to the alphabetical code.
You can only do this if there are sub terms given for this condition, if not; just list the previously existing condition.

Medical codes are the basis for all statistics related to morbidity, mortality and development of care pathways (a tool to reduce the variability in clinical practice) therefore it is essential that coding guidelines and Inpatient coding rules are followed to ensure the highest levels of accuracy.