2027 ICD-10-CM Diagnosis Code P71.2Neonatal hypomagnesemia
ICD-10-CM Codes›P00–P96›P70-P74›P71
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
P71.2 is a billable ICD-10-CM diagnosis code for neonatal hypomagnesemia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 44 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified perinatal conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autosomal dominant primary hypomagnesemia with hypocalciuria
- Familial hypomagnesemia hypercalciuria nephrocalcinosis with severe ocular involvement
- Familial hypomagnesemia-hypercalciuria
- Familial primary hypomagnesemia with hypercalciuria and nephrocalcinosis
- Familial primary hypomagnesemia with hypercalciuria and nephrocalcinosis without severe ocular involvement
- Familial primary hypomagnesemia with normocalciuria
- Familial primary hypomagnesemia with normocalciuria and normocalcemia
- Hypocalciuria
- Hypomagnesemia
- Hypomagnesemia co-occurrent with normocalciuria
- Neonatal hypomagnesemia
- Neonatal tetany due to hypomagnesemia
- Primary hypomagnesemia
- Tetany
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to P71.2: its own notes plus those printed at block P70-P74 and Chapter 16. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- transitory endocrine and metabolic disturbances caused by the infant's response to maternal endocrine and metabolic factors, or its adjustment to extrauterine environment
- conditions that have their origin in the fetal or perinatal period (before birth through the first 28 days after birth) even if morbidity occurs later
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.
Notes
General instructions on how these codes are used.
- Codes from this chapter are for use on newborn records only, never on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name P71.2, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming P71.2: they are not reported together with it, unless the two conditions are unrelated.
- R79.0 Abnormal level of blood mineralneonatal hypomagnesemia (P71.2)
- Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
neonatal P71.2
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
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Read the full article at MedlinePlus
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Convert P71.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About P71.2Overview
What is the ICD-10 code for neonatal hypomagnesemia?
The ICD-10-CM code for neonatal hypomagnesemia is P71.2 (sometimes written as P712). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is P71.2 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neonatal hypomagnesemia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does P71.2 group to?
When neonatal hypomagnesemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, with relative weights from 4.1073 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is P71.2 a CC or MCC?
CMS lists P71.2 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 44 closely related codes in its exclusion list.
What is the ICD-9 equivalent of P71.2?
Under the General Equivalence Mappings, neonatal hypomagnesemia converts to ICD-9-CM 775.4 (hypocalcem/hypomagnes NB). The mapping is approximate, so confirm the match fits the documentation.
