Free interactive tool
Good Faith Estimate Dispute Checker: The $400 Test
If you were uninsured or chose not to use insurance, and a provider or facility billed you at least $400 more than its own good faith estimate, you can ask for a federal payment decision through the patient-provider dispute resolution process. You must start within 120 days of receiving the first bill, and the fee is $25. The $400 test applies to each provider or facility on the estimate separately, not to the whole visit, which is where most readers go wrong. This checker applies the test row by row and gives you the date to start by.
Compare each estimate with its bill
Runs in your browser. What you enter is not sent to us or recorded. Do not enter names of patients or account numbers.
| Provider or facility on the estimate | Estimate total | Billed total | Over estimate | Remove |
|---|---|---|---|---|
| — | ||||
| — |
The rules the checker applies (read September 28, 2026)
| Rule | What it says | Source |
|---|---|---|
| Who can use it | An uninsured or self-pay patient who received a good faith estimate. Providers must give one when you schedule care at least 3 business days ahead, or when you ask for one. | 45 CFR 149.620(a), 149.610 |
| The $400 test | The total billed by a provider or facility is at least $400 more than the total expected charges for that same provider or facility on the estimate. Billed charges count even for items the estimate left out. | 149.620(a)(2)(ii)-(iii), (b)(1) |
| Deadline | Your request must be postmarked within 120 calendar days of receiving the first bill with the charges. CMS describes it as a bill dated within the last 120 days, so the checker counts from the bill date, which is the earlier and safer start. | 149.620(c)(1); CMS, dispute a bill |
| Fee | $25, non-refundable. If the decision goes your way, the provider takes it off what you owe. | CMS; 149.620(g) |
| While it is open | The provider must not send the bill to collections (or must stop collecting), must pause late fees, and must not retaliate. | 149.620(c)(5)-(6) |
| What gets decided | For each item on the estimate: if the provider cannot give credible information that the extra cost was medically necessary and could not reasonably have been foreseen, you pay the estimate. If it can, you pay the lower of the bill and a median payment amount, but never less than the estimate. An item that was not on the estimate is set at $0 unless the provider justifies it the same way. You and the provider can still settle before the decision. | 149.620(f) |
When the checker does not fit
- Insurance paid part of the bill: this process is not for you. Compare the bill with your explanation of benefits using the EOB check.
- You never got a good faith estimate: the dispute needs a copy of it. You can still ask the provider for an itemized bill and a discount; see negotiating a medical bill.
- A provider billed you but was not on the estimate: the $400 test compares each provider with its own estimate, so start by asking that provider why it was left out. One exception: if a co-provider on the estimate was replaced by another one, the replacement’s bill is tested against the original co-provider’s estimate, unless the replacement gave you a new estimate of its own (149.620(b)(2)).
- A state can run its own process instead of the federal one when HHS finds it meets the federal standards (149.620(h)). CMS routes your request if that applies.
What to gather before you start
- The good faith estimate (a photo or scan is fine).
- The first bill with the disputed charges, showing its date.
- The date of service, a short description, and the state where you were treated.
- The provider’s contact details if the estimate does not show them.
Start online or by mail or fax from CMS’s dispute-a-bill page (last modified September 19, 2026, read September 28, 2026). This checker does not submit anything and does not decide eligibility; the dispute resolution entity does.
Worked example (hypothetical)
A self-pay patient has a scheduled outpatient procedure. The good faith estimate lists the facility at $3,000 and the surgeon at $2,000. The bills, dated October 1, 2026, come to $3,300 from the facility and $2,450 from the surgeon.
- Facility: $300 over its estimate. Not eligible ($100 short).
- Surgeon: $450 over its estimate. Eligible.
- Together the bills are $750 over, but only the surgeon’s bill can go to dispute. The patient should start by January 29, 2027, 120 days after the bill date, and pay the $25 fee.
- If the surgeon cannot justify the extra $450 as medically necessary and unforeseeable, the decision is the $2,000 estimate, less the $25 fee: $1,975.