HCIM

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 also very similar. Anyone who is qualified to code ICD-9-CM should be able to easily make the transition to coding ICD-10-CM.

Many improvements have been made to coding in ICD-10-CM. For example, a single code can be found to report a disease and its current manifestation (i.e. type II diabetes with diabetic retinopathy). In fracture care, the code differentiates between an encounter for an initial fracture, follow-up for a fracture that is healing normally, follow-up for a fracture in malunion or nonunion, and follow-up for late effects of a fracture. Likewise, the trimester is designated in obstetrical codes.

While much has been said about the huge increase in the number of codes under ICD-10-CM, some of this growth is due to laterality. For example, while an ICD-9-CM code may identify a condition of 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.

No. & Type of Digits
ICD-9 codes consist of 3-5 digits:
• Chapters 1-7 are numeric
• Supplemental chapters: the first digit is alpha (E or V) and the rest are numeric

ICD-10-CM codes consist of 3-7 alphanumeric characters:
• Digit 1 is alpha
• Digit 2 is numeric
• Digits 3-7 are alpha or numeric

ICD-10-PCS codes consist of 7 alphanumeric characters:
• Each digit can be alpha or numeric
• Numbers used are 0-9
• Alpha letters I and O are not used in order to eliminate confusion

Volume of Codes
2009 totals, according to the U.S. Department of Health and Human Services:
ICD-9-CM: 17,000
Diagnosis: 13,000
Procedure: 4,000

ICD-10: 140,694
Diagnosis (ICD-10-CM): 68,105
Procedure (ICD-10-PCS): 72,589

Format & Structure
The format and structure of the ICD-10 codes varies greatly from the previous diagnosis codes. The ICD-10-CM is divided into an index. The first is the alphabetical list of terms and their corresponding code. The second is the Tabular List, a chronological list of codes divided into chapters that represent different conditions or body systems. There are also two parts to the Index – the Index to External Causes of Injury and the Index for Diseases and Injury. The Index and Tabular portions of the ICD-10-CM include the conventions and structural notes.

The Tabular List contains alphanumeric categories, subcategories, and codes. When a three character category has no more subdivisions, it is considered a code. Each level of subdivision after the category is a subcategory. The ‘code’ is considered complete once there are no more subcategories. A code indicated to have a 7^th character is considered incomplete without the missing character.

In order to be reportable, only a complete ‘code’ can be used. Subcategories or diagnoses that are not complete cannot be used for reporting. When there is an unknown subcategory, the place holder X is allowable in either the 5^th or 6^th position. This placeholder allows for the future addition of characters, thereby accommodating expansion when needed. The notes in the Tabular List will indicate categories where a 7^th character is required.

The abbreviations NEC and NOS are still used in both the Index and Tabular sections. When used in a narrative statement, the word “and” is defined as “and/or.” To locate a code and its classification, first refer to the Tabular List. The Index does not always provide the full code and therefore it is necessary to review both the Index and the Tabular List.

The 10^th revision of the International Classification of Diseases consists of:
• a tabular list containing cause of death titles and codes
• inclusion and exclusion terms for cause of death titles
• an alphabetical index to diseases and nature of injury, external causes of injury, table of drugs, and chemicals
• descriptions, guidelines, and coding rules

ICD-10 has two components:
ICD-10-CM
ICD-10-CM is the new diagnosis coding system that is being developed as a replacement for ICD-9-CM, Volumes 1 & 2. The number of diagnostic codes under ICD-10-CM will swell from around 13,000 to 68,000.

ICD-10-PCS
ICD-10-PCS, for “procedural coding system,” is being developed as a replacement for ICD-9-CM, Volume 3, for inpatient procedure reporting. ICD-10-PCS would be used by hospitals and payers. ICD-10-PCS is significantly different from Volume 3 and from CPT codes, and will require significant training for users. The number of inpatient procedure codes will jump from 4,000 to 72,500 with ICD-10-PCS. ICD-10-PCS will not affect the coding of physician services in their offices. However, physicians should be aware that documentation requirements under ICD-10-PCS are quite different, so their inpatient medical record documentation will be affected by this change.

The International Classification of Diseases (ICD) is the international standard diagnostic classification for all general epidemiological purposes, many health management purposes, and for clinical use. This includes the analysis of the general health situation of population groups, as well as monitoring the incidence and prevalence of diseases and other health problems in relation to other variables such as the characteristics and circumstances of the individuals affected, reimbursement, resource allocation, quality, and guidelines.

 ICD-9 code sets have been in use since 1979 with annual revisions. ICD-10 was endorsed by the 43^rd World Health Assembly in May 1990 and came into use in World Health Organization (WHO) States in 1994. The USA is one of the few developed countries that have not transitioned to ICD-10-CM and ICD-10-PCS.

 In August 2008, the Department of Health & Human Services proposed that new code sets be used for reporting diagnoses and procedures on health care transactions in the United States. The Proposed Rule was published for review on August 22, 2008. On January 15, 2009, the U.S. Department of Health and Human Services (HHS) published a final rule establishing ICD-10 as the new national coding standard. The implementation date has been set for October 1, 2013.

 * An electronic copy of the Final Rule can be found here.