2027 ICD-10-CM Diagnosis Code E83.31Familial hypophosphatemia
ICD-10-CM Codes›E00–E89›E70-E88›E83
- Billable — Valid for Submission
- Risk Adjusts — HCC 50
- Chronic Condition
E83.31 is a billable ICD-10-CM diagnosis code for familial hypophosphatemia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 642. Coders also document this condition as autosomal dominant hypophosphatemic bone disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.
For Medicare Advantage risk adjustment, E83.31 maps to CMS-HCC Category 50 (Amyloidosis, Porphyria, and Other Specified Metabolic Disorders) under the V28 model, adding a risk factor of about 0.648 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
E83.31 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autosomal dominant hypophosphatemic bone disease
- Autosomal dominant hypophosphatemic rickets
- Autosomal recessive hypophosphatemic bone disease
- Dominant hypophosphatemia with nephrolithiasis and/or osteoporosis
- Dysplasia with defective mineralization
- Hereditary hypophosphatemic rickets with hypercalciuria
- Phosphopenic type rickets
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to E83.31: its own notes plus those printed at E83.3, E83, block E70-E88, and Chapter 4. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Vitamin D-resistant osteomalacia
- Vitamin D-resistant rickets
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- vitamin D-deficiency rickets (E55.0)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- disorders of pyrophosphate metabolism (E83.82-)
- Ehlers-Danlos syndromes (Q79.6-)
Notes
General instructions on how these codes are used.
- All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name E83.31, its category, or a range that includes it.
Excludes1 5
These codes carry an Excludes1 note naming E83.31: they are not reported together with it, unless the two conditions are unrelated.
- E55.0 Rickets, activevitamin D-resistant rickets (E83.31)
- M83 Adult osteomalaciavitamin D-resistant osteomalacia (E83.31)
- M83 Adult osteomalaciavitamin D-resistant rickets (active) (E83.31)
- E61 Deficiency of other nutrient elementsdisorders of mineral metabolism (E83.-) names E83.-, which includes this code
- R79.0 Abnormal level of blood mineraldisorders of mineral metabolism (E83.-) names E83.-, which includes this code
Code First 1
These codes say to code first a condition named in the note, and E83.31 is one of the conditions named.
- M90.8 Osteopathy in diseases classified elsewherevitamin-D-resistant rickets (E83.31)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
vitamin-D-resistant in adults E83.31
carpus E83.31
clavicle E83.31
femur E83.31
fibula E83.31
finger E83.31
humerus E83.31
ilium E83.31
ischium E83.31
metacarpus E83.31
metatarsus E83.31
multiple sites E83.31
neck E83.31
pubic ramus E83.31
radius E83.31
rib E83.31
scapula E83.31
skull E83.31
tarsus E83.31
tibia E83.31
toe E83.31
ulna E83.31
vertebra E83.31
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Hypophosphatemia, Familial
an inherited condition of abnormally low serum levels of phosphates (below 1 mg/liter) which can occur in a number of genetic diseases with defective reabsorption of inorganic phosphorus by the proximal renal tubules. this leads to phosphaturia, hypophosphatemia, and disturbances of cellular and organ functions such as those in x-linked hypophosphatemic rickets; osteomalacia; and fanconi syndrome.
Patient EducationClinical
Metabolic Disorders
Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert E83.31 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E83.31Overview
What is the ICD-10 code for familial hypophosphatemia?
The ICD-10-CM code for familial hypophosphatemia is E83.31 (sometimes written as E8331). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is E83.31 (Disorders of phosphorus metabolism and phosphatases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report familial hypophosphatemia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does E83.31 group to?
When familial hypophosphatemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 642 (inborn and Other Disorders of Metabolism), which carries a relative weight of 1.3226. Higher weights mean higher Medicare reimbursement.
Can E83.31 be reported with E55.0?
Not as a rule. The Excludes1 note on E83.31 lists "vitamin D-deficiency rickets (E55.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of E83.31?
Under the General Equivalence Mappings, familial hypophosphatemia converts to ICD-9-CM 275.3 (dis phosphorus metabol). The mapping is approximate, so confirm the match fits the documentation.
What HCC is E83.31?
E83.31 (familial hypophosphatemia) maps to CMS-HCC Category 50 (Amyloidosis, Porphyria, and Other Specified Metabolic Disorders), commonly written as HCC 50, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. In the Part D prescription drug model it maps to RxHCC 42.
Does E83.31 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, E83.31 adds a risk adjustment factor of about 0.648 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.362 to 0.883 depending on the payment segment). HCC 50 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 50 category page.
