ICD-10 Overview and Impact on Medical Groups

What is ICD-10?

ICD-10 is the 10th revision of the World Health Organization’s International Classification of Diseases (ICD) coding system. The ICD-10-CM (Clinical Modification) codes are used to capture diagnoses in all healthcare settings, while ICD-10-PCS (Procedure Coding System) codes are used to capture procedures only in inpatient settings.

The ICD-10 code set is set to replace ICD-9 in the US on October 1, 2015. All medical practices will need to switch to ICD-10 by the deadline or they will no longer be able to obtain reimbursement for the care they provide to patients. Payers, clearinghouses, billing services, and all other entities covered by HIPAA will need to comply with ICD-10.

It’s critical to prepare your practice proactively for ICD-10. ICD-10 is a monumental change with wide-reaching implications for your organization, but with the right preparation, technology, and support, you’ll be able to minimize disruption to your practice.

Why the Move to ICD-10?

  • ICD-10 accommodates greater clinical detail, which allows for several benefits, such as:
    • More accurate claims processing and reimbursement
    • Better data to measure treatment outcomes and report on quality of care
    • Easier identification of patients for disease management programs
    • Improved analysis of disease patterns and tracking of public health outbreaks
  • ICD-9 is more than 30 years old and contains outdated terminology. ICD-10 reflects current medical practice more closely.
  • The structure of ICD-9 codes limits how many new codes can be created and many ICD-9 categories are full. Thus, as the medical world makes new discoveries, there are no numbers available for these new diagnoses.

ICD-10 is not going to change how physicians practice, but it will change what is documented.

— White Plume Technologies: “Framing the Impact of ICD-10”

How Does ICD-10 Differ From ICD-9?


  • ICD-9 has 13,000 diagnosis codes
  • ICD-9 codes have 3-5 digits
  • ICD-9 codes are primarily numeric


  • ICD-10 has 68,000 diagnosis codes
  • ICD-10 codes have 3-7 digits
  • ICD-10 codes are alphanumeric

The key changes to clinical documentation include:

ICD-10 requires a greater level of specificity in clinical documentation. Physicians will need to document with the required granularity 1) to ensure billing staff have the necessary details to code correctly, and 2) so the documentation supports the codes submitted.Examples of extra detail required in ICD-10 include:

  • More specific anatomical and physiological information
  • Severity – for example, Asthma is categorized as either mild intermittent, mild persistent, moderate persistent, or severe persistent
  • Laterality – nearly 25% of the ICD-10 codes are the same except for specifying left or right2
  • Encounter Sequence – almost 25% of the ICD-10 codes are the same except for indicating initial encounter, subsequent encounter, or sequelae3

How Can My Practice Prepare?

The scope of this change and its many implications, particularly for documentation and coding, are undoubtedly intimidating. In fact, in a June 2013 survey by MGMA, 70% of respondents said they are “very concerned” with ICD-10’s changes to documentation and almost 60% forecasted that it would be “much more difficult” for coding staff to select the right diagnosis codes4.

To mitigate the impact of ICD-10 on your practice (and related anxiety), it’s essential to prepare well in advance for a smooth rollout – including evaluating current resources (technology and staff), obtaining training for you and your team, and testing ICD-10 workflows proactively.

Learn more about the key steps for preparing your practice for ICD-10.

1 http://www.himss.org/files/HIMSSorg/content/files/TheValueofICD-10.pdf
2 CMS, ICD-10 Implementation Guide for Small and Medium Practices
3 Ibid.
4 MGMA Legislative and Executive Advocacy Response Network, ICD-10 Implementation Study, June 2013.