The CCW includes variables for 66 conditions – 27 common chronic conditions and 40 other chronic or potentially disabling conditions, which identify additional chronic health, mental health and substance abuse conditions. These variables are developed to facilitate researchers in the identification of cohorts of beneficiaries with specific conditions. Researchers may request data for a specific predefined cohort based on any of the categories on this page.
The condition variables are developed from algorithms that search the CMS administrative claims data for specific diagnosis codes, MS-DRG codes, or procedure codes. On October 1, 2015 the conversion from the 9th version of the International Classification of Diseases to version 10 occurred. Regardless of when a claim was submitted for payment, services that occurred prior to October 1, 2015, use ICD-9 codes.
The CCW algorithm specifications may change slightly from year to year due to changing coding standards. The Change History document is provided to assist CCW data users to identify changes in the CCW Condition Category algorithms.
All of the variables listed on this page are currently available in the Master Beneficiary Summary File (MBSF), Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) and Medicaid Enrollee Supplemental File (MESF).
The Applying Chronic Conditions to Medicaid Data document provides guidance when applying Chronic Conditions or Other Chronic Health, Mental Health, and Potentially Disabling Conditions algorithms to Medicaid data.
Other Chronic Health, Mental Health, and Potentially Disabling Conditions
There are 40 other chronic health, mental health, substance abuse, and potentially disabling condition categories. These conditions are designed to enhance research of the Medicare-Medicaid dual enrolled population, however they are available for all non-dually enrolled Medicare and Medicaid beneficiaries as well.
Original Version - 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).
* There are also variables that measure care (largely Medicaid services) provided to individuals with HIV/AIDS. These variables are not included in the Master Beneficiary Summary File (MBSF) or Medicaid Enrollee Supplemental File (MESF).