International Classification of Diseases, (ICD-10-CM/PCS) Transition – Impact on Public Health

How might you be affected by the transition?

The effects of the new ICD-10-CM/PCS codes are anticipated to be multifaceted with deep impacts on systems, processes, and people.


Changes may be needed to accommodate the new codes in the following ways:

  • Extend character length to 7
  • Increase messaging capacity
  • Increase storage capacity
  • Modify system logic and edits
  • Update system documentation
  • Modify links with other systems


Modifications may be needed for public health business processes:

  • Statistical analysis programs
  • Data extraction programs
  • Data tables
  • Publications
  • Reports
  • Health condition definitions (e.g., for case reports)
  • Trend analyses (e.g., analysis over time that will span 2015 and beyond)


  • Primary users: For those who will need to assign diagnosis and/or procedure codes, you will need thorough training in one or both of the ICD-10-CM/PCS code sets
  • Secondary Users: For those who utilize already coded ICD data, you will need to learn the new codes that apply to your data.

Training of staff will be vital to a smooth transition

Transition effects on public health

The transition from International Classification of Diseases, 9th Revision (ICD-9-CM) to ICD-10-CM/PCS code sets presents challenges for health officials who rely on the receipt of ICD-9-CM coded data to assess trends in health conditions over time. ICD-9-CM and ICD-10-CM/PCS are dramatically different in both scope and scale, and concerns about comparability of the code sets have strong implications for public health surveillance activities and data. The October 1st 2015 date of the ICD-10-CM/PCS transition presents challenges because analyses are traditionally aligned with calendar year rather than federal government fiscal year.

The challenges facing public health surveillance activities are anticipated to be as follows:

  • Analyzing multi-year data across code sets
  • Reporting 9 months of ICD-9-CM data and 3 months of ICD-10-CM/PCS in same year
  • Different condition definitions across code sets
  • Lacking ICD-10 expertise in public health sector
  • Achieving consensus on transition issues among stakeholders
  • Training needs for public health workforce
  • Competing priorities with Meaningful Use and shrinking budgets

How do I know if I’m impacted?