The CCW includes variables for 66 conditions – 27 common chronic conditions and 39 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.

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).

CCW Chronic Conditions

There are 27 chronic condition categories, available for file years 1999 - forward.

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).

Other Chronic Health, Mental Health, and Potentially Disabling Conditions

There are 39 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.


Other Chronic or Potentially Disabling Conditions

 ADHD, Conduct Disorders, and Hyperkinetic Syndrome  Personality Disorders
 Alcohol Use Disorders  Post-Traumatic Stress Disorder (PTSD)
 Anxiety Disorders  Pressure and Chronic Ulcers
 Autism Spectrum Disorders  Schizophrenia
 Bipolar Disorder  Schizophrenia and Other Psychotic Disorders
 Cerebral Palsy  Sensory - Blindness and Visual Impairment
 Cystic Fibrosis and Other Metabolic Developmental Disorders  Sensory - Deafness and Hearing Impairment
 Depressive Disorders  Spina Bifida and Other Congenital Anomalies of the Nervous System
 Drug Use Disorders  Spinal Cord Injury
 Epilepsy  Tobacco Use
 Fibromyalgia, Chronic Pain and Fatigue  Traumatic Brain Injury and Nonpsychotic Mental Disorders due to Brain Damage
 Human Immunodeficiency Virus and/or Acquired Immunodeficiency Syndrome (HIV/AIDS) *  Viral Hepatitis (General), including:
  • Hepatitis A
  • Hepatitis B (acute or unspecified)
  • Hepatitis B (chronic)
  • Hepatitis C (acute)
  • Hepatitis C (chronic)
  • Hepatitis C (unspecified)
  • Hepatitis D
  • Hepatitis E
 Intellectual Disabilities and Related Conditions
 Learning Disabilities
 Leukemias and Lymphomas
 Liver Disease, Cirrhosis and Other Liver Conditions
 Migraine and Chronic Headache
 Mobility Impairments
 Multiple Sclerosis and Transverse Myelitis
 Muscular Dystrophy
 Opioid Use Disorder
 Other Developmental Delays
 Peripheral Vascular Disease (PVD)

* 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).

Proposed Algorithm for Sickle Cell Disease Indicator

Sickle cell disease is the most prevalent lifelong genetic blood disorder in the United States. CMS is making available for public comment the algorithm used to define a new sickle cell disease indicator:

Sickle Cell Disease Background and Algorithm

Please note that while CMS is requesting public comment on the algorithm used to define sickle cell disease, the final condition indicator, the respective algorithm and the availability to end users will ultimately be at the discretion of CMS.

Sickle cell disease (SCD) is the most prevalent lifelong genetic blood disorder in the United States, causing the body to produce abnormal red blood cells shaped like sickles or crescents, which do not properly deliver oxygen to body tissues. It impacts all systems in the body, and is characterized by acute and chronic pain. SCD disproportionately affects Black/African American and Latino(a) individuals. In order to better monitor the disease, facilitate research, and promote measurement consistency, CMS has endeavored to develop a person level indictor of sickle cell disease within the Chronic Conditions Warehouse (CCW) using administrative claims data.  Like other CCW condition variables, the final algorithm will be developed for use with both Medicare and Medicaid data.  Please note that all condition indicators that are developed from CMS Medicaid claims data are subject to unavoidable caveats related to state-variability in program benefits, coding practices, data quality and data completeness.  Please also note that since these issues are often more pronounced with managed care encounter claims, all Medicare and Medicaid claims-based algorithms are developed with an inherent mechanism which allows users the option to calculate rates based on cases identified via fee-for-service (FFS) claims, encounter claims or both.  Please also note that International Classification of Diseases- 9th Version (ICD-9-CM) -based algorithms are switched over to the ICD-10-CM codes starting with services (claims) October 2015.

Please send comments to by Friday, March 1, 2019.