The Clinical Classifications Software (CCS) for ICD-10-CM/PCS is one in a family of databases and software tools developed as part of the Healthcare Cost and Utilization Project (HCUP), a Federal-State-Industry partnership sponsored by the Agency for Healthcare Research and Quality (AHRQ). HCUP databases, tools, and software inform decision making at the national, State, and community levels.

Contents:

• Overview of CCS for ICD-10-CM/PCS Tool
• Description of CCS for ICD-10-CM/PCS
• Technical Guidance of CCS for ICD-10-CM/PCS Tool
• Downloading Information of CCS for ICD-10-CM/PCS Tool
• Publications Using CCS for ICD-10-CM/PCS Tool
• For More Information, Comments, or Questions About CCS for ICD-10-CM/PCS

The Clinical Classifications Software (CCS) for ICD-10-CM and PCS is a diagnosis and procedure categorization scheme that can be employed in many types of projects analyzing data on diagnoses and procedures. CCS is based on the International Classification of Diseases, 10th Revision (ICD-10), a uniform and standardized coding system. The ICD-10's multitude of codes—over 69,800 diagnosis codes and 71,900 procedure codes—are collapsed into a smaller number of clinically meaningful categories that are sometimes more useful for presenting descriptive statistics than are individual ICD-10 codes. It is based on the CCS for ICD-9-CM and attempts to map ICD-10-CM/PCS codes into the same categories.

CCS can be used to identify populations for disease- or procedure-specific studies or to develop statistical reports providing information (such as charges and length of stay) about relatively specific conditions. It can be a useful way to categorize conditions when exploring data and can serve as a tool for reporting statistical information on hospitalizations.

Users should note that the ICD-10-PCS was created as a complement to the ICD-10-CM diagnosis classification and to replace ICD-9-CM procedure codes for reporting inpatient procedures. ICD-10-PCS was intended to allow each code to follow a standard structure and a detailed description while being adaptable for future needs.

Logic Employed for ICD-10-CM/PCS CCS Mapping

In preparation for the October 2015 implementation of ICD-10-CM/PCS, the diagnosis and procedure tools from HCUP were converted to the new coding system.

The initial mapping was completed by linking ICD-10-CM/PCS codes to the current CCS AHRQ classification assignments via the General Equivalence Mappings (GEMs) available from the Centers for Medicare & Medicaid Services (CMS) Web site (see http://www.cms.gov/Medicare/Coding/ICD10/2014-ICD-10-CM-and-GEMs.html for more information on GEMS). Two GEMs are available for each code set (CM and PCS); ICD-9 to ICD-10 and ICD-10 to ICD-9. In order to ensure complete inclusion of both ICD-9-CM and ICD-10-CM/PCS codes, both code maps were combined and de-duplicated to form a complete many-to-many map that included all ICD-9-CM and ICD-10-CM/PCS codes. This approach was used to ensure that all codes would be utilized in the mapping process, which centered on single-level CCS. The combined GEMs files were processed to create three subsets of diagnosis and procedure codes: exact maps, approximate maps with unique ICD-10-CM/PCS to ICD-9-CM maps, and approximate maps with multiple ICD-10-CM/PCS to ICD-9-CM maps. These initial GEMs-driven maps were reviewed by credentialed coders trained in both ICD-9-CM and ICD-10-CM/PCS to ensure the validity of the map for use in formulating the CCS. Codes with multiple ICD-10-CM/PCS to ICD-9-CM maps were given additional review. The project was structured so that two coders reviewed each code set. When the coders did not initially map a code to the same CCS, the team reviewed the discrepancies and came to consensus for the CCS assignment. Initial maps were completed in September 2011.

The accuracy of the initial assessment was verified by reviewing a 20 percent sample of the CM and PCS files. Additional queries and checks were executed based on the results of the 20 percent sample review.

In 2013, reverse mapping validation of 100 percent of the ICD-10-CM/PCS CCS assignments was conducted to verify the accuracy of mapping of the CCS. Again using the updated GEMs combined files, a team of credentialed coders verified the CCS by comparing current ICD-9-CM AHRQ classification assignments with the initially mapped (2011) ICD-10-CM/PCS assignments. The GEMs map was applied in reverse to test the reliability of the CCS assignment for both the diagnosis and procedure code sets.

Diagnosis Codes

The single-level diagnosis classification scheme aggregates illnesses and conditions into 285 mutually exclusive categories, most of which are clinically homogeneous. Some heterogeneous categories were necessary; these combine a number of less common individual conditions within a body system. All codes in the diagnosis section of ICD-10-CM were classified, including External Cause codes, which were based on the ICD Injury Matrix from the Centers for Disease Control and Prevention (CDC).

Every effort was made to translate the CCS system to ICD-10-CM/PCS without making changes to the CCS assignments for diseases and conditions. However, because of the structure and greater specificity of ICD-10-CM there are some ICD-9-CM conditions that do not map to the same CCS in ICD-10-CM. For example; ICD-9-CM code 721.8, Other allied disorders of spine, is assigned to CCS 205, Spondylosis; intervertebral disc disorders; other back problems. The GEMs map this ICD-9-CM code to two ICD-10-CM codes.

• M25.78, Osteophyte, vertebrae, assigned to CCS 212, Other bone disease and musculoskeletal deformities
• M48.9, Spondylopathy, unspecified, assigned to CCS 205, Spondylosis; intervertebral disc disorders; other back problems

Even though the code description for M48.9 is more specific than the ICD-9-CM code 721.8, the CCS assignment to CCS 205 was preserved. However, code M25.78 is much more specific than 721.8 and resulted in a different CCS assignment, CCS 212, because osteophyte did not fit into CCS 205. Therefore, when users of the system are comparing ICD-9-CM to ICD-10-CM, it is important to remember that one ICD-9-CM code may map to multiple ICD-10-CM codes, of which some may be closer matches to the ICD-9-CM code/description than others.

External Cause Codes

CCS assignment for external cause codes, found in Chapter 20 of ICD-10-CM, are based on the CDC ICD-10-CM Non-Poisoning Cause Matrix and the ICD-10-CM Poisoning Matrix. There are some exceptions to the CDC mechanism of injury assignments. For example, categories X71-X83, Intentional self-harm, are assigned to CCS 662, Suicide and intentional self-inflicted injury, rather than the mechanism of injury assigned by the CDC.

The following ICD-10 codes were not included in the CDC matrices, but were assigned in the CCS:

• Categories Y62-Y69, Misadventures to patients during surgical and medical care, are assigned to CCS 2616, Adverse effects of medical care
• Categories Y70-Y82, Medical devices associated with adverse incidents in diagnostic and therapeutic use, are assigned to CCS 2616, Adverse effects of medical care
• Categories Y83-Y84, Surgical and other medical procedures as the cause of abnormal reaction of the patient, or of later complication, without mention of misadventure at the time of the procedure, are assigned to CCS 2616, Adverse effects of medical care
• Category Y90, Evidence of alcohol involvement determined by blood alcohol level, is assigned to CCS 2620, External cause: unspecified
• Category Y92, Place of occurrence of the external cause, is assigned to CCS 2621, External cause: Place of occurrence
• Category Y93, Activity codes, is assigned to CCS 2620, External cause: unspecified
• Category Y95, Nosocomial condition, is assigned to CCS 2620, External cause: unspecified
• Category Y99, External cause status, is assigned to CCS 2620, External cause: unspecified

Procedure Codes

The single-level procedure classification scheme contains 231 mutually exclusive categories. Many of the categories represent single procedures; however, some procedures that occur infrequently are grouped according to three dimensions: (1) the relevant body system, (2) whether they are used for diagnostic or therapeutic purposes, and (3) whether they are considered operating room or nonoperating room procedures, according to Medicare severity–diagnosis related groups (MS-DRG) definitions.

The ICD-9-CM procedure section (Volume 3) contains just over 3,900 codes. The ICD-10-PCS code set contains over 71,900 codes. Therefore, the GEMs contain very few exact matches for procedures. Additionally, ICD-10-PCS is a new code set; it does not follow the conventions or structure of the ICD-9-CM procedure section. One of the major changes is the exclusion of diagnostic information from procedures. For example, ICD-9-CM subcategories 75.5, repair of current obstetric laceration of uterus, and 75.6, repair of other current obstetric laceration, were procedures reported only for pregnant women who delivered. These ICD-9-CM codes are assigned to CCS 140, Repair of current obstetric laceration. However, the diagnosis of the patient no longer has bearing in the assignment of the ICD-10-PCS code. Repair codes are reported for the procedures, regardless of the reasons. Therefore CCS 140, Repair of current obstetric laceration is not populated with ICD-10-CM codes because ICD-10 procedure that would be assigned here could be performed for reasons other than pregnancy/delivery. There are seven PCS CCS categories that are not populated by ICD-10-PCS codes: 57, 68, 140, 143, 151, 169, and 206.

The removal of diagnostic information along with the new structure of ICD-10-PCS also warranted the revision of the labels for some PCS CCS categories. Below is a listing of the PCS CCS categories with revised labels.

Revised CCS PCS labels (PDF file, 81 KB).

As with the diagnosis CCS categories, every effort was made to translate the CCS system to ICD-10-PCS without making changes to the CCS assignments for procedures. However, because of the new structure and expanded code availability in PCS this was more difficult than on the diagnosis side. In ICD-10-PCS each component of the major procedure is reported separately (this excludes the surgical approach, surgical closure, etc.). This is a significant change for reporting procedures that affects not only the CCS for the procedure but also the volume of codes. In ICD-10-PCS four procedure codes may be reported, whereas only one is reported in ICD-9-CM for a single operative session. For example, ICD-9-CM code 52.7, Radical pancreaticoduodenectomy (Whipple procedure) is reported as one operative session where numerous surgical components are performed. However, in ICD-10-PCS each component of the procedure is reported with a separate code. Below are the available coding options to be selected based on the medical record documentation for the encounter. One code from each of the four categories (root operation plus body system) would be selected to fully report the procedure in ICD-10-PCS.

Abbreviations: OR, operating room; GI, gastrointestinal.

ICD-9-CM CCS 99, Other OR gastrointestinal therapeutic procedures, is populated with only one code for a Whipple procedure; however, in ICD-10-PCS, CCS 94 will be populated with one code for the GI Bypass component, CCS 75 will be populated with one code for the GI Resection component, and CCS 99 will be populated with two possible codes for the Hepatobliary Bypass and Resection components. A total of four CCS categories will be activated in ICD-10-PCS for the Whipple procedure. Additionally, because of the added specificity in ICD-10-PCS, two of the gastrointestinal components of the Whipple procedure are now reported at a greater level of specificity (CCS 94 and 75) than is allowed in ICD-9-CM.

Multilevel Tools

Because of the increased specificity of ICD-10-CM/PCS and the changes in the two Code Set structures, it was not possible to translate most multilevel categories to ICD-10-CM/PCS within the current structure. The exceptions are the first- and second-level multilevel categories. These categories work with ICD-10-CM/PCS structure and have been added to the CCS tool files (columns 4–8). The specificity of categories increases with the higher levels, such that second-level categories are more specific than first-level categories. The first-level categories are identified by one whole digit (1–18), whereas the second-level categories include one decimal point.

The CCS tool files are located in the Downloading Information of CCS for ICD-10-CM/PCS Tool section below.

System Requirements

In order to use the CCS for ICD-10-CM/PCS files, you will need a program (such as WinZip®) that will allow you to decompress or “unzip” files. You will also need approximately 15 megabytes of disk space available on your hard drive to accommodate all of the CCS for ICD-10-CM/PCS files.

Required Data Elements

The CCS tool files for ICD-10-CM/PCS require the following variables on the input data:

1. Diagnosis codes (ICD-10-CM) with no embedded periods for the CM tool
2. Diagnostic codes (ICD-10-PCS) with no embedded periods for the PCS tool

File Layout

The ICD-10-CM and PCS tool files (CSV) are composed of eight fields separated by commas. The files are organized as follows:

• Field 1: Diagnosis or Procedure Code
• Field 2: CCS Category
• Field 3: Code Description
• Field 4: CCS Category Description
• Field 5: Multi-level 1 Category
• Field 6: Multi-level 1 Category Description
• Field 7: Multi-level 2 Category
• Field 8: Multi-level 2 Category Description

"Unzipping" Files

There are two downloadable self-extracting zipped files, called ccs_dx_icd10cm_2017.zip (for the diagnoses) and ccs_pr_icd10pcs_2017.zip (for the procedures). Users are advised to:

1. Create a subdirectory (or folder) called CCS on your hard drive (e.g., C:\CCS)
2. Download and save ccs_dx_icd10cm_2017.zip and ccs_pr_icd10pcs_2017.zip to this subdirectory
3. Using WinZip (or comparable program), double click on each zip file to expand the files

The zipped files will unzip (expand for normal use) the following files: ccs_dx_icd10cm_2017.csv and ccs_pr_icd10pcs_2017.csv. Note that the original files (ccs_dx_icd10cm_2017.zip and ccs_pr_icd10pcs_2017.zip) will remain intact.

Using Translation Files

The translation files translate specific ICD-10-CM or PCS codes into CCS categories. Your use of these files will depend on the software system being utilized. For example, if you are using SAS, you can adapt these translations to create a SAS PROC FORMAT. If you are working with SPSS, you can adapt these translations into VALUE LABELS or into a series of recodes.

Representation of ICD-10-CM diagnosis codes

In practice, ICD-10-CM diagnoses are represented by 3- to 7-character codes with explicit decimals. In the files you downloaded and in the vast majority of data files, ICD-10-CM diagnoses are represented with implicit decimals (no decimals present). (Alphanumeric codes are always enclosed in quotation marks.) Examples are given below.

For proper handling of diagnosis codes:

• Alphanumeric diagnosis codes must be left-justified so that there are two spaces following a five-character diagnosis code and one space following a six-character diagnosis code. For example, 'J206 '.
• Trailing blanks should never be zero-padded (filled with zeroes so that all seven characters are filled for codes that should be three or four characters long). For example, 'A191' should not be changed to 'A191000'.

Representation of ICD-10-PCS Procedure Codes

In practice, ICD-10-PCS procedures are represented as seven-character codes. All seven characters must be specified in order for the code to be valid. Each character in the seven-character code represents an aspect of the procedure. ICD-10-PCS procedure codes do not contain implicit or explicit decimals.

For proper handling of procedure codes:

• Leading zeroes must be preserved; they are significant.

Note: The CCS diagnosis and procedure tools were updated in FY 2017 with new codes.

Shift-click from this Web page: Your browser may support loading the files for CCS for ICD-10-CM/PCS from this Web page. To download the files from this Web page, click on the following links with the right mouse button and select "Save Link As" (Netscape) or "Save Target As" (Internet Explorer). After saving a file, find the file by using Windows® Explorer (Windows 98/95/NT/Vista/7) or File Manager (Windows 3.x) and then open it by double clicking on it.

CCS for ICD-10 Information

CCS Category Names (Full Labels) (PDF file, 161 KB).

ASCII CCS for ICD-10 files for Use with user analytic software (i.e., SAS, STATA, or SPSS)

CCS for ICD-10-CM (ZIP file, 628 KB Valid through October 1, 2017)

CCS for ICD-10-PCS (ZIP file, 531 KB Valid through October 1, 2017)

There are currently no publications using CCS for ICD-10-CM/PCS Tool. Click here to see a partial list of publications using CCS for ICD-9-CM Tool.

Questions regarding the CCS may be directed to HCUP User Support through the following channels:

• Email: hcup@ahrq.gov

Phone (toll free): 1-866-290-HCUP.