E32.9 ICD-10-CM Code: Disease of thymus, unspecified
E32.9 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools
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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Disorders of other endocrine glands (E20-E35)
E32.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceDisease of thymus, unspecified
A disease or disorder of the thymus gland that cannot be specified further. The thymus is a small gland in the chest that helps develop immune cells.
Buddy Insight
Disease of the thymus, unspecified, indicates a documented thymic disorder where the specific type has not been further characterized.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 030
Code-level coefficient reference
ESRD/PACE
MappedHCC 23
Code-level coefficient reference
RXHCC
MappedHCC 43
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Excludes 2
OfficialNo Excludes 2 notes are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Related Codes
Includes
OfficialNo Includes notes are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Excludes 1
Official- transitory endocrine and metabolic disorders specific to newborn (P70-P74)Inherited from E00-E89, E20-E35, E32
- galactorrhea (N64.3)Inherited from E00-E89, E20-E35, E32
- gynecomastia (N62)Inherited from E00-E89, E20-E35, E32
- aplasia or hypoplasia of thymus with immunodeficiency (D82.1)Inherited from E00-E89, E20-E35, E32
- myasthenia gravis (G70.0)Inherited from E00-E89, E20-E35, E32
Code First
OfficialNo Code First sequencing instructions are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for E32.9. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is E32.9 an HCC code?
E32.9 is not in the CMS-HCC V28 or V24 community payment model. E32.9 has a separate mapping under the CMS-HCC ESRD model (HCC 23 (Other Significant Endocrine and Metabolic Disorders)) and the Part D RxHCC model (HCC 43 (Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders)); the applicable result needs member context. E32.9 also appears in the HHS-HCC commercial risk model (HCC 030 (HHS-HCC 030 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping.
- Code
- E32.9
- Description
- Disease of thymus, unspecified
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work E32.9 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for E32.9
For E32.9, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
E32.9 is the ICD-10-CM diagnosis code for disease of thymus, unspecified. A disease or disorder of the thymus gland that cannot be specified further. The thymus is a small gland in the chest that helps develop immune cells. E32.9 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).
E32.9 has no mapping under the CMS-HCC V28 or V24 community payment models. E32.9 has a separate mapping under the CMS-HCC ESRD model (HCC 23 (Other Significant Endocrine and Metabolic Disorders)) and the Part D RxHCC model (HCC 43 (Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders)); the applicable result needs member context. E32.9 also appears in the HHS-HCC commercial risk model (HCC 030 (HHS-HCC 030 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.
Use this code only when the specific thymus disease is unknown or not documented.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for E32.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the specific thymus disease is unknown or not documented
- •Review medical records for more specific thymus conditions (myasthenia gravis, thymoma, etc.) before assigning this unspecified code
Clinical Significance
Disease of the thymus, unspecified, indicates a documented thymic disorder where the specific type has not been further characterized. The thymus is critical for immune system development, and unspecified thymic disease may reflect incomplete workup or documentation rather than a truly indeterminate condition. Further clinical evaluation is typically warranted.
Documentation Requirements
- ✓Documentation should indicate why the thymic disease remains unspecified and what workup has been performed or is planned.
- ✓Imaging results, lab findings, and any associated symptoms should be recorded.
- ✓The provider should be queried for additional specificity to determine if E32.0, E32.1, E32.8, or a neoplasm code would be more appropriate.
Commonly Confused Codes
- •E32.0 (Persistent hyperplasia of thymus) for documented thymic enlargement.
- •E32.1 (Abscess of thymus) for infectious thymic disease.
- •E32.8 (Other diseases of thymus) when a specific non-neoplastic thymic condition is identified.
- •G70.0x (Myasthenia gravis) for the autoimmune neuromuscular condition often associated with thymic pathology.