In many ways, ICD-10-CM is quite similar to ICD-9-CM. The guidelines, conventions, and rules are very similar. The organization of the codes is very similar. Healthcare professionals qualified to code ICD-9-CM should transition to coding ICD-10-CM with minimal effort.
Many improvements have been made to coding in ICD-10-CM. For example, a single code can report a disease and its current manifestation (i.e., type II diabetes with diabetic retinopathy). In fracture care, the code differentiates an encounter for an initial fracture; follow-up of fracture healing normally; follow-up with fracture in malunion or nonunion; or follow-up for late effects of a fracture. Likewise, the trimester is designated in obstetrical codes.
While much has been said about the increase in the number of codes under ICD-10-CM, some of this growth is due to laterality. While an ICD-9-CM code may identify a condition of, for example, the ovary, the parallel ICD-10-CM code identifies four codes: unspecified ovary, right ovary, left ovary, or bilateral condition of the ovaries.
The big differences between the two systems are differences that will affect information technology and software at your practice. Here’s a chart showing the differences:
|Volume of codes
|Composition of codes
||Mostly numeric, with E and V codes alphanumeric. Valid codes of three, four, or five digits.
||All codes are alphanumeric, beginning with a letter and with a mix of numbers and letters thereafter. Valid codes may have three, four, five, six or seven digits.
|Duplication of code sets
||Currently, only ICD-9-CM codes are required. No mapping is necessary.
||For a period of two years or more, systems will need to access both ICD-9-CM codes and ICD-10-CM codes as the country transitions from ICD-9-CM to ICD-10-CM. Mapping will be necessary so that equivalent codes can be found for issues of disease tracking, medical necessity edits and outcomes studies.