What is ICD-10 code E78.3?

E78.3 is the ICD-10-CM diagnosis code for Hyperchylomicronemia. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E78.3 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E78.3 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E78.3 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E78.3 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for E78.3?

E78.3 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards E78.3 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting E78.3?

Verify the underlying cause (Type I, Type V hyperlipoproteinemia, or secondary causes) as this may require additional coding for the primary condition Look for documentation of associated conditions such as pancreatitis, eruptive xanthomas, or lipemia retinalis, which should be coded separately if present

E78.3: Hyperchylomicronemia — ICD-10

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupE78.3Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)

E78.3

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Hyperchylomicronemia

This condition involves abnormally high levels of chylomicrons (fat particles) in the blood, usually caused by the body's inability to properly break down dietary fats. It can lead to fatty deposits in the blood and increase the risk of pancreatitis and heart disease.

Buddy Insight

Hyperchylomicronemia involves persistently elevated chylomicrons in fasting plasma, often resulting in extremely high triglyceride levels (frequently above 1,000 mg/dL).

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 47

Disorders of Fatty-Acid and L...

RAF 0.0

Code Trumping

Basket needed

Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

E78Disorders of lipoprotein metabolism and other lipidemias

E78.3Hyperchylomicronemia

Inclusion Terms

Official

Chylomicron retention disease
Fredrickson's hyperlipoproteinemia, type I or V
Hyperlipidemia, group D
Mixed hyperglyceridemia

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E78.3 in this effective period.

Related Child Codes

Official

E78.0Pure hypercholesterolemia

E78.1Pure hyperglyceridemia

E78.2Mixed hyperlipidemia

E78.4Other hyperlipidemia

E78.5Hyperlipidemia, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for E78.3 in this effective period.

Excludes 1

Official

sphingolipidosis (E75.0-E75.3)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E78.3 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E78.3 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E78.3 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Provider diagnosis of hyperchylomicronemia or chylomicronemia syndrome

Fasting lipid panel showing chylomicron persistence and severely elevated triglycerides

Whether primary (familial/genetic) or secondary etiology

History of pancreatitis episodes related to chylomicronemia

MEAT Support

HCC Buddy guidance

Provider diagnosis of hyperchylomicronemia or chylomicronemia syndrome

Fasting lipid panel showing chylomicron persistence and severely elevated triglycerides

Whether primary (familial/genetic) or secondary etiology

History of pancreatitis episodes related to chylomicronemia

Audit Caution

HCC Buddy guidance

Using E78.1 (pure hypertriglyceridemia) when chylomicronemia is specifically documented

Not distinguishing between Type I (familial LPL deficiency) and Type V hyperlipoproteinemia, both of which present with chylomicronemia

Failing to separately code pancreatitis episodes caused by chylomicronemia

Coding as mixed hyperlipidemia when the predominant issue is chylomicron accumulation

Common Mistakes

HCC Buddy guidance

E78.1 — Pure hyperglyceridemia: elevated triglycerides without specific chylomicron persistence

E78.2 — Mixed hyperlipidemia: combined cholesterol and triglyceride elevation without chylomicron focus

E78.6 — Lipoprotein deficiency: opposite problem — decreased lipoproteins

K85.9 — Acute pancreatitis, unspecified: a complication of hyperchylomicronemia, code both

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is E78.3 an HCC code?

No. E78.3 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 47, Disorders of Fatty-Acid and Lipid Metabolism

0.000

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 E78.3

For E78.3to 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 E78.3 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

E78.3 is the ICD-10-CM diagnosis code for hyperchylomicronemia. This condition involves abnormally high levels of chylomicrons (fat particles) in the blood, usually caused by the body's inability to properly break down dietary fats. It can lead to fatty deposits in the blood and increase the risk of pancreatitis and heart disease. E78.3 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).

E78.3 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

E78.3 maps only to RxHCC 47 (Disorders of Fatty-Acid and Amino-Acid Metabolism) with no RAF weight. Despite being more severe and rarer than common hyperlipidemia, it has no V24 or V28 CMS-HCC mapping and does not contribute to Medicare Advantage RAF scores.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E78.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the underlying cause (Type I, Type V hyperlipoproteinemia, or secondary causes) as this may require additional coding for the primary condition
•Look for documentation of associated conditions such as pancreatitis, eruptive xanthomas, or lipemia retinalis, which should be coded separately if present

Clinical Significance

Hyperchylomicronemia involves persistently elevated chylomicrons in fasting plasma, often resulting in extremely high triglyceride levels (frequently above 1,000 mg/dL). This condition carries a high risk of recurrent acute pancreatitis and may be primary (familial chylomicronemia syndrome due to lipoprotein lipase deficiency) or secondary, requiring strict dietary fat restriction and specialized management.

Documentation Requirements

✓Provider diagnosis of hyperchylomicronemia or chylomicronemia syndrome
✓Fasting lipid panel showing chylomicron persistence and severely elevated triglycerides
✓Whether primary (familial/genetic) or secondary etiology
✓History of pancreatitis episodes related to chylomicronemia
✓Dietary management plan (severe fat restriction)
✓Genetic testing results if familial form is suspected (LPL, APOC2, APOA5 mutations)

Commonly Confused Codes

•E78.1: Pure hyperglyceridemia: elevated triglycerides without specific chylomicron persistence
•E78.2: Mixed hyperlipidemia: combined cholesterol and triglyceride elevation without chylomicron focus
•E78.6: Lipoprotein deficiency: opposite problem: decreased lipoproteins
•K85.9: Acute pancreatitis, unspecified: a complication of hyperchylomicronemia, code both