Differences between ICD-9-CM and ICD-10-CM

The basic differences between ICD-9-CM and ICD-10-CM may be tabulated as below:

14000 plus codes only More than 69000 codes
Codes consists 3 – 5 characters Codes consists 3 – 7 characters
First digit is numeric or alphanumeric First digit of every code is alpha
Second, third, fourth and fifth digit always numeric Second and third digits are numeric, but fourth, fifth, sixth and seventh digit may be alpha or numeric
No 7th character extension 7th character extension in codes to identify episodes of care
No concept of place holder Place holder "x" or dummy "x" concept, present
Single excludes Excludes 1 and Excludes 2 present
V and E codes as supplementary classification No supplementary classification
Code titles may have incomplete code description Code titles may have incomplete code description Code titles have complete code description in all codes
Code definitions lacks laterality Laterality is added to code descriptions

Improvements In ICD-10-CM Over ICD-9-CM

  • ICD-10-CM has the same hierarchical structure as ICD-9-CM, but the codes are all alphanumeric and all letters except U are used.
  • New diseases and conditions that are not identified with unique codes in ICD-9-CM are identified with unique codes in ICD-10-CM (ex. Codes for blood type and alcohol level). In addition new diseases, etiology or treatment protocols have been reclassified more appropriately in ICD-10-CM.
  • ICD-10-CM provides additional information related to ambulatory & managed care encounters.
  • Injury codes are more expanded in ICD-10-CM than ICD-9-CM and are grouped by body parts (arm, leg, ankle and so on) instead by categories of injury or type (sprain, fracture, dislocation and so on) in ICD-9_CM.
  • More number of combination codes to reduce the number of codes required for fully describing a condition. Eg. Atherosclerotic heart disease with angina was coded with two codes in ICD-9-CM can be coded with a single code I25.119.
  • Incorporation of common fourth & fifth digit subclassifications.
  • Addition of sixth & seventh character subclassifications.
  • Introduction of laterality (right-left) to fully describe injury codes.
  • Greater specificity in code assignments.
  • No supplemental classifications (ex. V codes & E codes of ICD-9-CM), which are incorporated in the tabular list as individual chapters.
  • Provision of place holder dummy "x" at 5th or 6th character place for future expansion of the codes without disturbing the character structure that follows dummy "x". The new structure of code allows easy expansion in codes than was possible with ICD-9-CM.
  • Exclude notes are expanded to provide guidance on the hierarchy of chapters and to clarify priority in code assignments.
  • Creation of excludes1 & excludes2 in the conventions to segregate two codes incompatible on the same medical record by using exclude1 and to provide additional information to use additional code to fully describe a condition by using exclude2.
  • Postoperative complications codes have been expanded and a clear distinction has been made between intraoperative complications and postprocedureal disorders.
  • Obstetric codes in ICD-10-CM indicate which trimester the patient is in and no longer identify whether the patient has delivered or not, which is a constant source of confusion and error prone for coders in ICD-9-CM.
  • Many of the category code/subcategory code titles have been changed to reflect new technology and more recent medical terminology.
  • Classification refinement for increased data granularity. In general, the classification allows greater specificity in code assignments.

Differences between ICD-9-CM Volume 3 and ICD-10-PCS

The basic differences between ICD-9-CM Volume 3 and ICD-10-PCS may be tabulated as follows:

ICD-9-CM Volume 3 ICD-10-PCS
Approximately 3800 plus codes More than 71000 codes
3 – 4 digits in codes with decimal point after first two digits All codes with 7 characters without decimal point
All codes numeric Alphanumeric
Less specific in description and explanation More specific
More NOS and NEC codes Few NOS or NEC codes
Diagnostic, clinical or pathologic terminology present in code description No diagnostic, clinical or pathological terms used in code description
Laterally not attended Laterality described in code descriptions
Less granular More granularity

Apart from the above basic differences between ICD-10-CM and ICD-10-PCS, ICD-10-PCS has the following important characteristics that make it to be more acceptable in present day healthcare reimbursement system.

  • Completeness—there is a unique code for all substantially different procedures.
  • Expandability—as new procedures are developed, the structure of ICD-10-PCS allows them to be easily incorporated as unique codes.
  • Multi-axial—ICD-10-PCS consists of independent characters, with each individual component retaining its meaning across broad ranges of codes to the extent possible.
  • Standardized terminology—ICD-10-PCS includes definitions of the terminology used. Each term is assigned a specific meaning in the system.

Important Note:

ICD-10-PCS will not affect physician practices, outpatient facilities and hospital outpatient departments usage of Current Procedural Terminology (CPT) codes on Medicare claims. CPT will still be in use. However, physicians should be aware that documentation requirements under ICD-CM-PCS are quite different, so their inpatient medical record documentation will be affected by this change.