Changes in Medicare's Chronic Condition Files and Disparities in Dementia Identification

In 2017, the Chronic Condition Warehouse released a 30-condition Chronic Condition file (CC30), which fully replaced the prior 27-condition file (CC27) in 2022. CC30 shortened the look-back period for dementia identification from 3 to 2 years and raised the required outpatient/carrier claims from 1 to 2. This change may disproportionately affect individuals with limited access to health care. This study aimed to quantify how the CC27-CC30 transition affects dementia identification across population subgroups.