E27.1
BillablePrimary adrenocortical insufficiency
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E27.1 an HCC code?
Yes. E27.1 maps to Other Significant Endocrine and Metabolic Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for E27.1
For E27.1 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E27.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E27.1 is the ICD-10-CM diagnosis code for primary adrenocortical insufficiency. A condition where the adrenal glands do not produce enough hormones, particularly cortisol and aldosterone, due to primary gland failure. E27.1 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering disorders of other endocrine glands (e20-e35).
Under the CMS-HCC V28 risk adjustment model, E27.1 maps to Other Significant Endocrine and Metabolic Disorders (HCC 51) with a community, non-dual, aged base RAF weight of 0.233. Under the older V24 model, E27.1 mapped to the same category but with a base RAF weight of 0.230 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is primary insufficiency (adrenal gland failure), not secondary to pituitary disease. Because E27.1 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E27.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is primary insufficiency (adrenal gland failure), not secondary to pituitary disease
- •Often associated with autoimmune destruction; document any known etiology for more specific coding if available
Clinical Significance
Primary adrenocortical insufficiency (Addison disease) results from destruction of the adrenal cortex, most commonly by autoimmune adrenalitis in developed countries, causing deficiency of cortisol, aldosterone, and adrenal androgens. Without treatment, this condition is fatal, and even with treatment, patients face lifelong risk of adrenal crisis during physiologic stress.
Documentation Requirements
- ✓Document the underlying etiology (autoimmune, infectious, hemorrhagic, infiltrative, genetic), cortisol and adrenocorticotropic hormone levels (low cortisol with elevated adrenocorticotropic hormone), adrenocorticotropic hormone stimulation test results, adrenal antibody status, mineralocorticoid and glucocorticoid replacement regimen, and sick-day management plan.