The CCW contains two versions of the Chronic Conditions: 30 CCW Chronic Conditions (2017 forward) and 27 CCW Chronic Conditions (1999–2020). CMS developed the 27 CCW Chronic Condition variables from algorithms validated from the research literature and criteria used by other federal sources. In 2020, CMS contracted an expert panel to refine and enhance these algorithms, resulting in the 30 CCW Chronic Condition algorithms.

The Chronic Conditions File Enhancement White Paper document provides more detail on the differences between the two versions and recommendations for researchers.

30 CCW Chronic Conditions (2017 forward)

There are 30 CCW Chronic Condition categories, available for file years 2017 forward. These reference only ICD-10 diagnosis codes and have modified look-back periods, qualifying claims, and codes.

All variables listed here are currently available in the Master Beneficiary Summary File (MBSF) in the MBSF_CHRONIC_YYYY file.

30 CCW Chronic Conditions Algorithms and Change History

* Within the 27 CCW Chronic Conditions, this condition is "Acquired Hypothyroidism."
Within the 27 CCW Chronic Conditions, this condition is "Alzheimer’s Disease, Related Disorders, or Senile Dementia."

27 CCW Chronic Conditions (1999–2020)

There are 27 CCW Chronic Condition categories, available for file years 1999–2020. These reference both ICD-9 and ICD-10 diagnosis codes.

All variables listed here are currently available in the Master Beneficiary Summary File (MBSF) in the MBSF_CC_YYYY file. The last data year for this file will be 2021.

They are also available in Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) (2006–2012) and Medicaid Enrollee Supplemental File (MESF) (1999–2013).

The Applying Chronic Conditions to Medicaid Data (MAX) document provides guidance when applying Chronic Conditions or Other Chronic Health, Mental Health, and Potentially Disabling Conditions algorithms to Medicaid data.

27 CCW Chronic Conditions Algorithms and Change History
27 CCW Chronic Conditions Algorithms Reference List

Original 21 CCW Chronic Conditions for file years 1999–2010

This original version is no longer available but listed here for reference purposes. These conditions were in the previously available Beneficiary Annual Summary File (BASF).

Original 21 CCW Chronic Conditions Algorithms
Original 21 CCW Chronic Conditions Algorithms Reference List