Magnesium (CPT 83735)
Medicare Rate vs. Lab Charges
Medicare pays $6.31 for this test. Labs commonly charge $25.00–$85.00. That's a 296%–1247% markup above what Medicare pays.
What This Test Is
Magnesium is a mineral essential for muscle and nerve function. Low magnesium causes muscle cramps, weakness, and irregular heart rhythm. High levels are rare but can occur with kidney disease. It's tested to evaluate muscle symptoms or electrolyte imbalance.
Medicare Rate vs. Lab Charges
| Medicare Allowable Rate | $6.31 |
| Typical Lab Charge Range | $25.00–$85.00 |
| Average Markup Above Medicare | 296%–1247% |
Does Medicare Cover This Test?
Yes, Medicare Part B covers magnesium testing when ordered to evaluate electrolyte imbalance, muscle symptoms, or kidney disease.
Common Reasons for Denial
- Routine screening in asymptomatic patients
- Tested too frequently without symptom change
- No diagnosis code documenting clinical reason
- Supplement monitoring without medical necessity
- Duplicate test within short timeframe
What To Do If You're Overcharged
If you received a lab bill that seems unusually high compared to Medicare rates:
- Check your Explanation of Benefits (EOB) from Medicare or your insurance to see what should have been paid.
- Request an itemized bill from the lab showing all charges.
- Compare to GougeStop rates for your area to see if the charge is reasonable.
- Contact the lab's billing department to dispute erroneous charges or negotiate a lower rate.
- File an appeal with Medicare if a claim was incorrectly denied.
Frequently Asked Questions
A: Muscle cramps, weakness, fatigue, irregular heart rhythm, and personality changes. But many causes of these symptoms exist—magnesium testing clarifies.
A: Only if magnesium deficiency is confirmed by blood test. Excess supplementation can cause diarrhea and interact with medications.
A: Yes, if ordered for a specific reason (muscle symptoms, electrolyte imbalance, kidney disease). Routine screening is less likely to be covered.