Home Health & Hospice

ICD-9 vs. ICD-10: Similarities and differences

Homecare Insider, June 10, 2013

An upgrade of the coding classification system was needed as ICD-9 has become outdated. Under ICD-9, new technologies, procedures and even diagnostic specificity is not detailed enough to capture the necessary data. ICD-10-CM also is consistent with other classifications systems including Diagnostic and Statistical Manual for Mental Disorders (DSM IV); ICD-O, which is used by Tumor Registry Programs; as well as Nursing Classification Systems.

A coding system is needed that has flexibility to add emerging diagnoses and procedures. A coding system is needed that captures accurate diagnoses for quality and reimbursement purposes. One area that ICD-9-CM does not capture is laterality. If a patient has bilateral fractures of the wrist, only one code to identify the fracture can be documented and coded. ICD-10-CM allows for both the fractures to be coded. ICD-10-CM will provide greater accuracy of diagnostic information through its increased specificity and increased number of code selections.

Similarities between ICD-10-CM and ICD-9-CM

Certain structural components are the same in both systems:

  • A hierarchal structure getting more specific with more digits
  • Conventions are similar
    • Brackets are used in the alphabetical index to represent manifestations
    • NOS means “not otherwise specified”
  • Must code to the greater level of specificity
  • Mechanics of looking up a diagnosis in the alphabetical index and then verifying in the tabular list is required

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

ICD-10-CM offers greater specificity and several new features including:

  • Expansion from five characters to seven characters
  • Additional of laterality (i.e., left, right)
  • Dummy place holder “x” to allow for future expansion and allow for the code to add the seventh character as needed
    • Injuries, obstetrics, external causes
  • Seventh character identifies encounter episode
  • Fractures require knowing open, closed, healing status, and encounter to determine the seventh character
  • Better usage of combination codes for both the diagnosis and manifestation
  • Diabetes section codes are separated by type I or type II
  • ICD-9-CM injuries are grouped primarily by type of injury
  • In ICD-10-CM injuries are grouped primarily by body area
  • Postoperative complications adds distinction between intraoperative complications and postprocedural disorders

Editor’s note: This is an excerpt from the Beacon Health book, ICD-10 Essentials for Homecare: Your Guide to Preparation and Implementation, by Joan L. Usher, BS, RHIA, COS-C, ACE. Click here to learn more about this important resource.

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