D80-D89 — Certain disorders involving the immune mechanism
ICD-10-CM codes D80-D89 cover certain disorders involving the immune mechanism, within diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism. The block holds 100 codes across 7 categories, of which 83 are billable and 17 are header codes that cannot be submitted on a claim.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
Includes
Conditions this code covers.
- defects in the complement system
- immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
- sarcoidosis
Risk adjustment in D80-D89
0 codes in this block map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded. Under-coding here is money left on the table; over-coding here is what audits are for.
- HCC 114 Common Variable and Combined Immunodeficiencies
- HCC 115 Specified Immunodeficiencies and White Blood Cell Disorders
- HCC 454 Stem Cell, Including Bone Marrow, Transplant Status/Complications
- HCC 93 Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders
- HCC 387 Pemphigus, Pemphigoid, and Other Specified Autoimmune Skin Disorders
What else to watch in D80-D89
- 83 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.