Hypomagnesemia ICD-10 Code: E83.42
Last updated: January 4, 2026
Hypomagnesemia (low serum magnesium) is coded as E83.42.
Primary Code
| Code | Description | Use |
|---|---|---|
| E83.42 | Hypomagnesemia | Low magnesium level |
Etiology Coding
Code the underlying cause when documented:
| Cause | Primary Code |
|---|---|
| Chronic alcoholism | F10.x |
| Malabsorption | K90.x |
| Diuretic-induced | T50.1X5- (adverse effect) |
| PPI-induced | T47.1X5- (adverse effect) |
| Renal wasting | N25.89 |
| DKA | E10.10/E11.10 |
| Refeeding syndrome | E43 |
Related Electrolyte Codes
| Code | Description |
|---|---|
| E83.42 | Hypomagnesemia |
| E83.52 | Hypercalcemia |
| E83.51 | Hypocalcemia |
| E87.6 | Hypokalemia |
| E87.1 | Hyponatremia |
Coding Tips
- Code etiology first: Alcoholism, malabsorption, drug adverse effect
- Symptomatic: Add codes for tetany (R29.0), arrhythmias (I49.x)
- Drug-induced: Code the adverse effect T-code + E83.42
- Multiple electrolytes: Code each disorder separately
Clinical Context
Low magnesium often occurs with:
- Hypokalemia (resistant to K+ replacement until Mg corrected)
- Hypocalcemia (Mg needed for PTH secretion)
- Chronic diuretic use
- Alcoholism
- GI losses (diarrhea, malabsorption)
Frequently Asked Questions
What is the ICD-10 code for hypomagnesemia?
E83.42 is the ICD-10 code for hypomagnesemia (low magnesium). This is a billable code used for low serum magnesium levels.
How do I code drug-induced hypomagnesemia?
Code the adverse effect first (T50.1X5- for diuretics, T47.1X5- for PPIs), then E83.42 for the hypomagnesemia.
Should I code hypokalemia with hypomagnesemia?
Yes. Code both E83.42 (hypomagnesemia) and E87.6 (hypokalemia) when both are present. They commonly co-occur and both affect treatment.
Related Resources
Last updated: January 2026. Code data reflects ICD-10-CM 2026 version. This guide is for educational purposes only. Always verify codes against current official guidelines.