Preparing for the ICD-10 Journey

by Sue Bowman, RHIA, CCS

After years of doubt as to whether ICD-10 was ever going to be implemented in the United States, the journey toward replacement of ICD-9-CM has finally gotten under way. The historic decision of the National Committee on Vital and Health Statistics (NCVHS) to send a letter to the Secretary of Health and Human Services (HHS) recommending the initiation of the regulatory process for the concurrent adoption of ICD-10-CM and ICD-10-PCS begins the process.

Time to Dust off Your ICD-10 Knowledge

The practice brief “Destination 10: Healthcare Organization Preparation for ICD-10-CM and ICD-10-PCS,” in this issue, describes the regulatory process required for ICD-10 to be adopted and the ways in which ICD-10 and ICD-10-PCS represent an improvement over ICD-9-CM.

Given the years of uncertainty surrounding ICD-10 implementation, many HIM professionals’ interest in and knowledge of ICD-10 have dwindled with time. Now it is time to recall those forgotten memories and refresh our knowledge of the ICD-10-CM and ICD-10-PCS coding systems.

As HIM professionals across the country prepare to lead ICD-10 implementation teams in their organizations, they need to take steps to become “experts” on how ICD-10-CM and ICD-10-PCS differ from ICD-9-CM. The basic understanding HIM managers need to lead implementation efforts is not the same type of knowledge as the in-depth skills in code application that those involved directly in the day-to-day coding function will need.

This article reviews the structure and unique characteristics of ICD-10-CM and ICD-10-PCS. It is not intended to be comprehensive. Use the resources listed in “To Learn More,” below, to continue to increase your familiarity with ICD-10-CM and ICD-10-PCS.

How Is ICD-10-CM Different?

ICD-10-CM has many similarities to ICD-9-CM. For example, it has the same hierarchical structure and many of the same conventions, instructional notes, and guidelines. ICD-10-CM will have much the same “look and feel” as ICD-9-CM; however, it includes a number of notable differences:

  • ICD-10-CM is entirely alphanumeric (all letters except U are used).
  • ICD-10-CM codes may be up to seven characters in length.
  • Some chapters have been restructured in ICD-10-CM.
  • Some diseases have been reclassified in ICD-10-CM.
  • New features have been added to ICD-10-CM.

Conditions with a recently discovered etiology or new treatment protocol have been reassigned to a more appropriate chapter. For example, gout is in the endocrine chapter in ICD-9-CM but in the musculoskeletal chapter in ICD-10-CM. And some conditions have been grouped in a more logical fashion than in ICD-9-CM.

“Excludes” notes were expanded to provide guidance on the hierarchy of chapters and clarify priority of code assignments. Also, two types of Excludes notes are clearly distinguished to eliminate confusion as to the meaning of the exclusion. An early draft of ICD-10-CM referred to three types of Excludes notes, but subsequent system revisions resulted in the use of only two types. An “excludes1” note designates codes that can never be used together. An “excludes2” note is used to clarify that the excluded condition is not a part of or included in the code.

In addition to the alphanumeric structure, ICD-10-CM embodies other differences in code structure. An “x” is used as a placeholder to save space for future expansion. So, for example, there may be a six-character code for which there is no fifth character subclassification at the present time. In this case, an “x” is used in the fifth character position. An example is code S63.8x1a, Sprain of other part of right wrist and hand, initial encounter.

Another change in ICD-10-CM is the use of extensions, which provide additional information in certain circumstances. Extensions are used in the obstetrics, injury, and external cause chapters and always occupy the final (seventh) character position in a code. The example above, code S63.8x1a, includes the extension “a” for “initial encounter.” The other applicable extensions for category S63 are “d” (subsequent encounter) and “q” (sequela).

Other notable changes in ICD-10-CM include:

  • Injuries are grouped by body part rather than category of injury.
  • Factors influencing health status and contact with health services (known as V codes in ICD-9-CM) and external causes of morbidity and mortality (known as E codes in ICD-9-CM) are considered part of the main classification in ICD-10-CM, not “supplementary” classifications.
  • Codes for postoperative complications have been expanded and moved to the appropriate procedure-specific body system chapter, and a new concept of “postprocedural disorders” has been added.
  • Combination codes have been created for commonly occurring symptoms/diagnoses and etiologies/manifestations.

What about ICD-10-PCS?

ICD-10-PCS was developed specifically as a replacement for ICD-9-CM Volume 3. Four major objectives guided the development of ICD-10-PCS:

  • Completeness: a unique code should exist for all substantially different procedures.
  • Expandability: as new procedures are developed, the system structure should allow them to be easily incorporated as unique codes.
  • Multiaxial: each code character should have the same meaning within the specific procedure section and across procedure sections, to the extent possible.
  • Standardized terminology: each term should be assigned a specific meaning, and the coding system should not include multiple meanings for the same term.

ICD-10-PCS has a seven-character alphanumeric code structure. Unlike ICD-9-CM, ICD-10-PCS codes do not exist as “finished” codes in the tabular listing. Rather, they exist as groups of interchangeable coding components called “characters,” which must be assembled into a code for each distinct procedure performed. So, in essence, the correct code is “built” for each procedure being coded.

Procedures are divided into 17 sections that relate to the type of procedure (see “Sections of ICD-10-PCS,” below, left). The first character of the procedure code identifies the section.

Sections of ICD-10-PCS
0 Medical and Surgical
1 Obstetrics
2 Placement
3 Administration
4 Measurement and Monitoring
5 Imaging
6 Nuclear Medicine
7 Radiation Oncology
8 Osteopathic
9 Physical Rehabilitation and Diagnostic Audiology
B Extracorporeal Assistance and Performance
C Extracorporeal Therapies
D Laboratory
F Mental Health
G Chiropractic
H Miscellaneous
J Substance Abuse Treatment


Characters 2 through 7 have a standard meaning within each section but may have different meanings across sections. The characters for the medical and surgical section are:
1 = section
2 = body system
3 = root operation
4 = body part
5 = approach
6 = device
7 = qualifier
Medical and Surgical Root Operations
0   Alteration
1   Bypass
2   Change
3   Control
4   Creation
5   Destruction
6   Detachment
7   Dilation
8   Division
9   Drainage
B   Excision
C   Extirpation
D   Extraction
F   Fragmentation
G   Fusion
H   Insertion
J   Inspection
K   Map
L   Occlusion
M   Reattachment
N   Release
P   Removal
Q   Repair
R   Replacement
S   Reposition
T   Resection
V   Restriction
W   Revision
X   Transfer
Y   Transplantation

The medical and surgical section contains 30 root operations (see “Medical and Surgical Root Operations,” above, right). Definitions of these operations can be found in the ICD-10-PCS training manual (see “To Learn More,” below). No diagnostic information is contained in ICD-10-PCS codes.

The ICD-10-PCS system contains an index and a tabular listing. The index allows codes to be located by looking up terms alphabetically. The main terms are root operations. However, common operative names, such as hysterectomy, can also be looked up, where a cross-reference directs the coder to the appropriate root operation term. The index provides only the first three or four characters of the procedure code. One must always refer to the tabular listing to obtain the complete code.

The tabular listing is arranged by sections, and most sections are subdivided by body system. There are separate tables for each root operation in a body system. The name of the section, body system, and root operation and its definition are listed at the top of each table. This list is followed by a grid, with the columns representing the last four characters of the code and the rows specifying the allowable combinations of these four characters. As demonstrated during the testing of ICD-10-PCS by the Clinical Data Abstraction Centers, the format of the tabular listing facilitates bypassing the index entirely and going directly to the tabular listing to assign a code.

Future articles in this column will address implementation strategies organizations should undertake during the next few years to ensure a successful and smooth transition to the new code sets.

To Learn More

  • The ICD-10-CM draft and ICD-10-CM official guidelines for coding and reporting are available at
  • “ICD-10-CM Overview: Deciphering the Code” is an Internet-based continuing education course (approved for eight AHIMA continuing education credits) and is available from AHIMA.
  • The ICD-10-PCS final draft and training manual is available at
  • ICD-10-CM Preview, by Anita Hazelwood and Carol Venable, can be ordered from the AHIMA Web site:
  • Six 2004 regional coding community seminars will include a two-hour segment on ICD-10-CM and ICD-10-PCS. 
  • AHIMA’s “Statement in Support of Prompt Adoption of ICD-10-CM and ICD-10-PCS Medical Code Set Standards in the United States” is available at
  • AHIMA’s testimony on ICD-10-CM and ICD-10-PCS before NCVHS is available at
  • “CodeWrite,” the online coding newsletter available to members of the Coding Community of Practice (CoP) and frequently distributed to coding roundtable participants in print form, will feature a regular column on practical application of ICD-10-CM and ICD-10-PCS codes. Members can log in at
  • The ICD-10 Implementation CoP offers an opportunity to network with colleagues on ICD-10 implementation strategies and ensures ready access to a wealth of ICD-10 resources. Members can log in at

Sue Bowman ( is director of coding policy and compliance at AHIMA.

Article citation:
Bowman, Sue. "Preparing for the ICD-10 Journey." (ICD-10: Mapping Our Course column) Journal of AHIMA 75, no.3 (March 2004): 60-62.