FY2027
MenuClose
Excludes1 pair

P71.2 vs R79.0

P71.2 and R79.0 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on R79.0
neonatal hypomagnesemia (P71.2)
P71.2

Neonatal hypomagnesemia

Billable
Chapter 16
Certain conditions originating in the perinatal period
Section
P70-P74
Indexed under
  • Hypomagnesemia › neonatal
R79.0

Abnormal level of blood mineral

Billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R70-R79
Use when the record says
  • Abnormal blood level of cobalt
  • Abnormal blood level of copper
  • Abnormal blood level of iron
  • Abnormal blood level of magnesium
  • Abnormal blood level of mineral NEC
  • Abnormal blood level of zinc
Indexed under
  • Abnormal, abnormality, abnormalities › blood level › cobalt
  • Abnormal, abnormality, abnormalities › blood level › copper
  • Abnormal, abnormality, abnormalities › blood level › iron
  • Abnormal, abnormality, abnormalities › blood level › magnesium
  • Abnormal, abnormality, abnormalities › blood level › mineral NEC

These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.

Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027