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Note: CDPS 7.0 is now available! To obtain a license or renew your license please contact Subramanian (Subbu) Venkatraman at:


The Chronic Illness and Disability Payment System (CDPS) is a diagnostic-based risk adjustment model that is widely used to adjust capitated payments for health plans that enroll Medicaid beneficiaries.

CDPS uses International Classification of Disease (ICD) codes to assign CDPS Categories that indicate illness burden related to major body systems (e.g. cardiovascular) or types of chronic disease (e.g. diabetes). Within each major category is a hierarchy reflecting both the clinical severity of the condition and its expected effect on future costs. Each of the hierarchical CDPS Categories is assigned a CDPS weight. CDPS weights are additive across major categories.

Medicaid Rx (MRX) is a pharmacy-based system that uses National Drug Classification (NDC) codes to assign MRX Categories based on types of pharmacotherapy. Each category is assigned a MRX weight.

CDPS+Rx is a combination of the CDPS and MRX models.

You may learn more about the CDPS from the Spring 2000 issue of Health Care Financing Review (requires Adobe Acrobat or Acrobat Reader).

For licensing CDPS including MRX and CDPS+MRx, please contact Subramanian (Subbu) Venkatraman at:

Using CDPS Risk Scores

CDPS risk scores are calculated at the individual level, but are applied at the group level. An individual risk score includes the sum of the intercept (or baseline), demographic (i.e. age and gender) weights, and weights for all indicated CDPS (or MRX or CDPS+Rx) categories. As described above, CDPS weights are hierarchical within major categories but are additive across major categories. In practice, this means, for example, that an individual will receive higher scores for multiple chronic conditions across different major categories, such as Cardiovascular and Diabetes, but will only receive the highest score for multiple conditions within a major category (e.g. for heart failure but not also for hypertension).

History of CDPS

The CDPS model was developed in 2000 using data from seven Fee-for-Service (FFS) Medicaid programs.  The model received major updates in 2009 (using national FFS Medicaid data from 2002-2005) and in 2014 (using additional national FFS Medicaid data from 2011). CDPS has also received regular annual updates to include the most recent ICD and NDC codes.

Major Revision of CDPS to 7.0

We have completed updating CDPS using data from three national Medicaid managed care plans from 2017-2019. We expect two main improvements in the CDPS model:

  • To the extent that new treatments and technology have changed how patients are treated, the relative weights estimated with 2011 data may not accurately reflect relative cost in 2019.

  • To the extent that patients are treated differently in FFS vs. managed care, the regression weights estimated with FFS data may not to reflect patterns of care in managed care organizations.

Participating Medicaid managed care plans are large national organizations with Medicaid contracts in a broad cross-section of states.


Relevant Papers and Additional Resources