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Prevalence and Medicare spending are presented for chronic condition co-morbidity at the national level.      Co-morbidity is illustrated by the combinations of the 21 chronic conditions. Dyads represent the combinations of two chronic conditions among Medicare beneficiaries with at least two of the conditions. There are 210 dyads. Triads represent the combinations of three chronic conditions among Medicare beneficiaries with at least three of the conditions. There are 1,330 triads.

The data are available as Excel files.

Note: On October 1, 2015 the conversion from the 9th version of the International Classification of Diseases (ICD-9-CM) to version 10 (ICD-10-CM) occurred. Regardless of when a claim was submitted for payment, services that occurred prior to October 1, 2015, use ICD-9 codes. Chronic conditions identified in 2015 are based upon ICD-9 codes for the first ¾ of the year (January-September) 2015 and ICD-10 codes for the last quarter of the year (October-December). Starting in 2016, chronic conditions identified are based upon ICD-10 codes for the full year. Detailed information on the identification of chronic conditions in the CCW is available at

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