Medical services not elsewhere classified
M0243 — Intravenous infusion or subcutaneous injection, casirivimab and imdevimab includes infusion or injection, and post administration monitoring
HCPCS code M0243 is used on U.S. medical bills for medical services not elsewhere classified: Intravenous infusion or subcutaneous injection, casirivimab and imdevimab includes infusion or injection, and post administration monitoring.
- Typical setting: Varies
- National avg charge (illustrative): Coverage and pricing vary widely — verify with insurer.
- Most-disputed reason: Service-definition mismatch
What it means
What M0243 actually means
Intravenous infusion or subcutaneous injection, casirivimab and imdevimab includes infusion or injection, and post administration monitoring.
The official CMS HCPCS Level II descriptor for this code is shown above. If the description on your bill does not match the service you actually received, that is a reason to ask for the itemized bill and dispute the line.
Common errors with this code
What goes wrong on real bills.
Use these as review prompts, not conclusions. The right next step is to compare the bill, itemized charges, and EOB before paying.
- Quantity or units of service that exceed what the medical record supports.
- Duplicate billing on the same date of service.
- Missing or incorrect modifier (e.g., JW for drug waste, RT/LT for sides).
- Service-definition mismatch without supporting documentation.
If you see M0243 on your bill
Three steps before paying.
1. Get the itemized bill. If your statement only shows a summary, request the CPT-level itemized bill before paying. Generate the request language →
2. Cross-check against the EOB. Compare what your insurer's Explanation of Benefits says you owe versus what the hospital is asking. They disagree more often than people think. Read the bill-vs-EOB guide →
3. Run a free Bill Scan. Upload the bill (and EOB if you have it) and BillBusted will flag the most likely issues with this specific code in your specific state. Run free scan →
Related codes
Other codes in this category.
People who land on M0243 often also see these adjacent codes on the same bill.
HCPCS
M0003 — Optimal care for patients with episodic neurological conditions mips value pathways
Opt care episod neuro mvp
HCPCS
M0004 — Quality care for patients with neurological conditions mips value pathway
Qual care neurologic cnd mvp
Related BillBusted guides
Plain-English reads if you see M0243 on a bill.
M0243 FAQ
Plain-English answers.
What is M0243 used for on a medical bill?
HCPCS code M0243 is used on medical bills for medical services not elsewhere classified: Intravenous infusion or subcutaneous injection, casirivimab and imdevimab includes infusion or injection, and post administration monitoring. Billing mistakes can happen, and codes in this category most often get flagged for service-definition mismatch. If you see M0243 on your bill, request the itemized statement and compare the units, date of service, and description to your Explanation of Benefits before paying.
How much should M0243 cost?
How much M0243 should cost depends on your payer and region. Billing mistakes can happen, and pricing for this HCPCS code is set by Medicare fee schedules for Medicare claims and by negotiated allowed amounts for commercial plans. Check the Medicare fee-schedule lookup tool, your insurer's member portal, or run a free BillBusted scan to compare your charge against typical allowed amounts.
Can I dispute a M0243 charge on my medical bill?
Yes, you can dispute a M0243 charge on your medical bill if the units, modifier, date of service, or coverage doesn't match the medical record or your insurance benefits. Request the itemized bill, compare to your EOB, and use BillBusted's Resolution Pack to draft the dispute letter if needed.
Don't pay M0243 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.