Question: Kansas Subscriber Answer: Use the anemia codes as the principal/first listed code if the reason for the encounter is to treat the anemia, states the ICD-9-CM Official Guidelines for Coding and Reporting, Oct. 2009, (www.cdc.gov/nchs/data/icd9/icdguide09.pdf). They may also be used as secondary codes if treatment of the anemia is a component of an encounter, but not the primary reason for the encounter. When using a code from subcategory 285 it is also necessary to use the code for the chronic condition causing the anemia, in this case chronic kidney disease (CKD). When assigning 285.21, it is also necessary to assign a code from category 585 to indicate the stage of chronic kidney disease. Stage II, code 585.2, equates to mild CKD.