CPT G0399: Home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation
Use this page to check what is on the bill and what details to ask for. It does not estimate a fair price or decide that a charge is wrong.
Is G0399 on a bill in front of you? Paste the codes and amounts and we check every line against the CMS national Medicare file, including the $466.71 providers submitted for G0399 on average, then write your dispute letter with those figures in it.
Three records to compare
What is CPT G0399?
In this lookup, CPT G0399 is labeled Home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation. CPT codes identify services and procedures for billing. The same code can produce different amounts based on the setting, contract, plan, units, modifiers, and other claim details.
If the description does not match what happened, ask the billing office to confirm the code and provide the record that supports it. Do not rely on a code label alone to decide whether the bill is correct.
Questions to check before you dispute it
- Does the code match the service? Ask for the itemized bill and the plain-English description used by the provider.
- Are the units and dates correct? Look for repeated lines, unexpected quantities, or a date that does not match the visit.
- Does the EOB match? Compare the billed amount, allowed amount, insurer adjustment, insurer payment, and patient responsibility.
- Is supporting documentation available? Ask which note, report, or order supports the billed code and any modifier.
- Was the claim processed under the right plan? Confirm the insurer, plan, network status, and place of service.
What CMS published for G0399
These are national averages Medicare published for 2024. The allowed amount is what Medicare paid plus the patient share. The submitted amount is what providers put on the claim before any contract or adjustment. The two are usually far apart, which is normal and is why the number on your bill is not the number anyone collects.
| Setting | Medicare allowed | Average submitted | Services |
|---|---|---|---|
| Office / outpatient | $69.02 | $466.71 | 69,421 |
| Facility | $44.46 | $336.17 | 4,019 |
For G0399, the average submitted charge is about 6.8 times the Medicare allowed amount. Across all 9,402 codes in this dataset the middle code sits at 4.8 times, and G0399 falls at the 76th percentile. That is a wider gap than most codes carry, which is worth asking about, though a wide gap on its own is not evidence of an error. None of this decides what you owe. Your plan's allowed amount and your own benefits do.
G0399 is billed in both settings, and Medicare allowed $24.56 more in the office setting on average. Place of service changes the amount, so confirm the setting on the claim matches where you were actually seen.
Source: Centers for Medicare & Medicaid Services, Medicare Physician & Other Practitioners - by Geography and Service, 2024 national figures, released 2026-05-21. Retrieved 2026-08-19.
https://data.cms.gov/provider-summary-by-type-of-service/medicare-physician-other-practitioners/medicare-physician-other-practitioners-by-geography-and-service
Hospital prices need an exact source
A national amount or a generic multiplier cannot tell you what this service should cost on your bill. A useful hospital comparison needs the hospital or location, this code or service, and the exact insurer and plan.
Keep gross charge, discounted cash price, payer-negotiated amount, and allowed amount separate. Save the hospital source file, file date, and matched plan with the result.
How to question a mismatch
- Write down the exact line, code, date, amount, and record that does not match.
- Ask the provider or insurer for a written explanation or corrected claim.
- Keep copies of the itemized bill, EOB, account ledger, notes, and every response.
- If coverage was denied, ask the insurer for the appeal steps and deadline that apply to your plan and denial notice.
- Review any letter before sending it. State what you can prove and ask for a specific correction or explanation.
Got CPT G0399 on your bill?
Paste the line items from your itemized bill. Every code is compared against the CMS national Medicare file, the lines worth questioning are flagged, and the dispute letter comes back with your own figures written into it. Reading the bill is free and the finished letter is $9 once.
Would rather write it yourself? The blank template is free.