Book excerpt: HCC basics
By Tracy Boldt, RN, BSN, CCDS, CDIP, and Ellen Jantzer, RN, MSN, CCDS, CCS, CRC
The hierarchical condition categories (HCC) are diagnosis code based on ICD-10 codes and include approximately 70 distinct disease groups derived from approximately 3,600 diagnosis codes that are mostly chronic but include some acute conditions, used primarily for outpatient services. The ICD-10 code book published by Optum includes the HCC designation along with CC/MCC. APCC and HCC University both have interactive tools to identify HCC codes.
The relationship between the ICD-10-CM diagnoses codes and the HCCs is one to many, meaning a single HCC may contain any number of ICD-10 diagnoses codes. Each HCC is assigned a relative factor or health risk score that is used to compute the patient’s risk adjustment factor. For example, HCC 21, Protein Calorie Malnutrition, includes:
- E41 Nutritional Marasmus
- E42 Marasmic Kwashiorkor
- E43 Unspecified Severe Protein Calorie Malnutrition
- E44.0 Moderate Protein Calorie Malnutrition
- E44.1 Mild Protein Calorie Malnutrition
- E45 Retarded Development following PCM
- E46 Unspecified Protein Calorie Malnutrition
- E64.0 Sequelae of Protein Calorie Malnutrition
- R64 Cachexia or Wasting Syndrome
Not all ICD-10-CM codes are reflected in HCC groupings; CMS identified diagnoses which:
- Are related to high costs
- Complicate coordination of care
- Increase potential care needs or medications
The list of such diagnoses and their corresponding HCC is updated annually by CMS and can be found here.
The basic HCCs categories include:
- Infection
- Neoplasm
- Diabetes
- Cerebrovascular disease
- Vascular
- Lung
- Metabolic
- Liver
- Gastrointestinal
- Musculoskeletal
- Eye
- Kidney
- Openings
- Amputations
- Blood
- Substance abuse
- Skin
- Injury
- Psychiatric
- Spinal
- Neurological
- Arrest
- Heart
- Complications
- Transplants
The ultimate payment is per HCC (not per diagnosis code), similar to the DRG system on the inpatient side, and is based on the highest-rated HCC within a category.
Editor’s note: This is an excerpt from The Outpatient CDI Specialist’s Complete Training Guide.