E79.89 ICD-10-CM Code: Other specified disorders of purine and pyrimidine metabolism
E79.89 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC coding software
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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)
E79.89
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOther specified disorders of purine and pyrimidine metabolism
Other rare inherited disorders affecting the body's ability to process purines and pyrimidines, which are building blocks of DNA.
Buddy Insight
Other specified disorders of purine and pyrimidine metabolism encompasses named purine/pyrimidine disorders without their own specific ICD-10-CM codes, including adenine phosphoribosyltransferase (APRT) deficiency, Kelley-Seegmiller syndrome (partial HPRT deficiency), and dihydropyrimidine dehydrogenase deficiency.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 029
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 E79.89. Check the code and parent instructions in the Code Book.
Excludes 2
Official- Ehlers-Danlos syndromes (Q79.6-)Inherited from E70-E88
Related Codes
Includes
OfficialNo Includes notes are included in this display for E79.89. 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, E70-E88, E79
- androgen insensitivity syndrome (E34.5-)Inherited from E00-E89, E70-E88, E79
- congenital adrenal hyperplasia (E25.0)Inherited from E00-E89, E70-E88, E79
- hemolytic anemias attributable to enzyme disorders (D55.-)Inherited from E00-E89, E70-E88, E79
- Marfan syndrome (Q87.4-)Inherited from E00-E89, E70-E88, E79
- 5-alpha-reductase deficiency (E29.1)Inherited from E00-E89, E70-E88, E79
- Ataxia-telangiectasia (Q87.19)Inherited from E00-E89, E70-E88, E79
- Bloom's syndrome (Q82.8)Inherited from E00-E89, E70-E88, E79
- Cockayne's syndrome (Q87.19)Inherited from E00-E89, E70-E88, E79
- calculus of kidney (N20.0)Inherited from E00-E89, E70-E88, E79
- combined immunodeficiency disorders (D81.-)Inherited from E00-E89, E70-E88, E79
- Fanconi's anemia (D61.09)Inherited from E00-E89, E70-E88, E79
- gout (M1A.-, M10.-)Inherited from E00-E89, E70-E88, E79
- orotaciduric anemia (D53.0)Inherited from E00-E89, E70-E88, E79
- progeria (E34.8)Inherited from E00-E89, E70-E88, E79
- Werner's syndrome (E34.8)Inherited from E00-E89, E70-E88, E79
- xeroderma pigmentosum (Q82.1)Inherited from E00-E89, E70-E88, E79
Code First
OfficialNo Code First sequencing instructions are included in this display for E79.89. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for E79.89. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for E79.89. 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 E79.89 an HCC code?
E79.89 has no mapping under the current CMS-HCC V28 community payment model. E79.89 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. E79.89 also appears in the HHS-HCC commercial risk model (HCC 029 (HHS-HCC 029 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping.
- Code
- E79.89
- Description
- Other specified disorders of purine and pyrimidine metabolism
- 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 E79.89 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for E79.89
For E79.89, 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
E79.89 is the ICD-10-CM diagnosis code for other specified disorders of purine and pyrimidine metabolism. Other rare inherited disorders affecting the body's ability to process purines and pyrimidines, which are building blocks of DNA. E79.89 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
E79.89 has no mapping under the current CMS-HCC V28 community payment model. E79.89 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. E79.89 also appears in the HHS-HCC commercial risk model (HCC 029 (HHS-HCC 029 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 a specific purine or pyrimidine disorder is not captured by other E79 codes.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for E79.89 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 a specific purine or pyrimidine disorder is not captured by other E79 codes
- •Provide detailed documentation of the specific metabolic disorder identified
Clinical Significance
Other specified disorders of purine and pyrimidine metabolism encompasses named purine/pyrimidine disorders without their own specific ICD-10-CM codes, including adenine phosphoribosyltransferase (APRT) deficiency, Kelley-Seegmiller syndrome (partial HPRT deficiency), and dihydropyrimidine dehydrogenase deficiency. These conditions have varied clinical presentations from kidney stones to severe drug toxicity.
Documentation Requirements
- ✓Specific purine or pyrimidine metabolism disorder documented
- ✓Confirmatory enzyme assay or genetic testing
- ✓Clinical manifestations specific to the disorder (kidney stones for APRT deficiency, hyperuricemia for Kelley-Seegmiller, fluoropyrimidine toxicity for DPD deficiency)
- ✓Treatment plan tailored to the specific deficiency
- ✓Family history and genetic counseling if applicable
Commonly Confused Codes
- •E79.1: Lesch-Nyhan syndrome: complete HPRT deficiency with neurological features, has its own code
- •E79.2: Myoadenylate deaminase deficiency: has its own specific code
- •E79.81: Aicardi-Goutieres syndrome: has its own specific code
- •E79.82: Hereditary xanthinuria: has its own specific code
- •E79.9: Disorder of purine and pyrimidine metabolism, unspecified: use only when no specific disorder is identified