International Classification of Diseases, Tenth Revision (ICD-10)

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International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM)

The International Classification of Diseases (ICD) is designed to promote international comparability in the collection, processing, classification, and presentation of mortality statistics. The ICD-10 is copyrighted by the World Health Organization (WHO), which owns and publishes the classification.

The ICD-10-CM is a morbidity classification published by the United States for classifying diagnoses and reason for visits in all health care settings. The ICD-10-CM is based on the ICD10, the statistical classification of disease published by the World Health Organization (WHO).

ICD-10-CM is planned as the replacement for ICD-9-CM Volumes 1 and 2.

Introduction to ICD-10-CM

Doctor Exam

ICD-10-CM is the United States’ clinical modification of the World Health Organizations’s ICD10. The term clinical is used to emphasize the modification’s intent: to serve as a useful tool in the area of classification of morbidity data for indexing of medical records, medical care review, and ambulatory and other medical care programs, as well as for basic health statistics. To describe the clinical picture of the patient the codes must be more precise than those needed only for statistical groupings and trend analysis.

WHO has authorized the development of an adaptation of ICD-10 for use in the United States for U.S. government purposes. As agreed, all modifications to the ICD-10 must conform to WHO conventions for the ICD. ICD-10-CM was developed following a thorough evaluation by a Technical Advisory Panel and extensive additional consultation with physician groups, clinical coders, and others to assure clinical accuracy and utility.

ICD-10-CM Final Rule

On January 16, 2009 HHS published a final rule adopting ICD-10-CM (and ICD-10-PCS) to replace ICD-9-CM in HIPAA transactions, effective ICD 10 implementation date of October 1, 2013. Until that time the codes in ICD-10-CM are not valid for any purpose or use.

UPDATE: On Monday, April 09, 2012 the Department of Health and Human Services (HHS) announced a proposed rule that would delay, from October 1, 2013 to October 1, 2014, the compliance date for the International Classification of Diseases, 10th Edition diagnosis and procedure codes (ICD-10).

UPDATE: In March 2014, The Senate voted on a bill to delay ICD10, from October 1, 2014 to October 1, 2015, the compliance date for the International Classification of Diseases, 10th Edition diagnosis and procedure codes (ICD-10).

ICD-10-CM Benefits and Characteristics

The clinical modification represents a significant improvement over ICD-9-CM and ICD-10. Specific improvements include: the addition of information relevant to ambulatory and managed care encounters; expanded injury codes; the creation of combination diagnosis/symptom codes to reduce the number of codes needed to fully describe a condition; the addition of sixth and seventh characters; incorporation of common 4th and 5th digit subclassifications; laterality; and greater specificity in code assignment. The new structure will allow further expansion than was possible with ICD-9-CM.

ICD-10-CM far exceeds its predecessors in the number of concepts and codes provided. The disease classification has been expanded to include health-related conditions and to provide greater specificity at the sixth digit level and with a seventh digit extension. The sixth and seventh characters are not optional; they are intended for use in recording the information documented in the clinical record.

ICD-10-CM Coding

There are many new conventions and general coding guidelines that must be followed with ICD-10-CM. Here is a partial list of the new guidelines:

  • The Alphabetic Index and Tabular List
  • The ICD-10-CM is divided into the Index, an alphabetical list of terms and their corresponding code, and the Tabular List, a chronological list of codes divided into chapters based on body system or condition. The Index is divided into two parts, the Index to Diseases and Injury, and the Index to External Causes of Injury. Within the Index of Diseases and Injury there is a Neoplasm Table and a Table of Drugs and Chemicals.
  • Format and Structure:
  • The ICD-10-CM Tabular List contains categories, subcategories and codes. Characters for categories, subcategories and codes may be either a letter or a number. All categories are 3 characters. A three-character category that has no further subdivision is equivalent to a code. Subcategories are either 4 or 5 characters. Codes may be 4, 5, 6 or 7 characters. That is, each level of subdivision after a category is a subcategory. The final level of subdivision is a code. All codes in the Tabular List of the official version of the ICD-10-CM are in bold. Codes that have applicable 7th characters are still referred to as codes, not subcategories. A code that has an applicable 7th character is considered invalid without the 7th character.
  • The ICD-10-CM uses an indented format for ease in reference.
  • Use of codes for reporting purposes
  • For reporting purposes only codes are permissible, not categories or subcategories, and any applicable 7th character is required.
  • Placeholder character
  • The ICD-10-CM utilizes a placeholder character “X”. The “X” is used as a 5th character placeholder at certain 6 character codes to allow for future expansion. An example of this is at the poisoning, adverse effect and underdosing codes, categories T36-T50. Where a placeholder exists, the X must be used in order for the code to be considered a valid code.
  • 7th Characters
  • Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.

For a complete set of coding guidelines, visit the CMS website.

CPT Codes

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ICD-9-CM Codes

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