The $400 Rule: How Uninsured and Self-Pay Patients Can Dispute a Bill That Beat Its Good-Faith Estimate
The $400 rule, in one paragraph
The No Surprises Act is a federal law that went into effect on January 1, 2022, and its requirements protect uninsured (or self-pay) consumers from many unexpected high medical bills (CMS: Medical bill rights; CMS: Providers, payment resolution with patients).
For people who pay cash, the law’s most concrete tool is a number. If a bill from one of your providers is at least $400 more than the good faith estimate that provider gave you, a formal federal dispute process opens up. An independent third party — a dispute resolution entity — reviews the bill and determines an appropriate payment (CMS: Dispute a medical bill).
That is a process, not a discount. It has a price ($25, non-refundable), a hard window (120 calendar days), and one of its three possible endings is your bill staying exactly where it is.
Why it matters at scale: with December 2025 data, the Urban Institute found 26.6 percent of adults owed medical debt, including 15.4 percent with past-due bills they could not pay (Urban Institute), while the KFF Health Care Debt Survey finds 41% of adults currently have some debt caused by medical or dental bills (KFF).
Who can use this process
CMS’s dispute page states that you can only dispute a bill if all of the following are true (CMS: Dispute a medical bill):
- When you got care, you didn’t have or didn’t use your health insurance to pay for it.
- Before you got care, you told your provider that you weren’t using insurance to pay for it.
- You got care on or after January 1, 2022.
- You have a good faith estimate that you received from your health care provider or facility three (3) days before your scheduled appointment.
- You have an initial bill dated within the last 120 calendar days (about 4 months).
- One of your providers or facilities charged at least $400 more than their good faith estimate.
The fourth condition is the one people miss. The estimate has to have reached you three days before the scheduled appointment. If it arrived later, or never arrived, the federal dispute process is not available to you — see the backup routes below.
“Self-pay” is broader than “uninsured.” You may choose not to use insurance if the service you need isn’t covered, or if it’s less expensive to pay out of pocket (CMS: Know your medical bill rights when not using insurance). You or your authorized representative may initiate the dispute (CMS: Providers, payment resolution with patients).
If you used health insurance, you don’t qualify to dispute a bill, and a bill you got because you haven’t met your deductible isn’t a No Surprises Act violation (CMS: Dispute a medical bill).
Step 1: Get the estimate in writing before care
You don’t need the term “Good Faith” to ask for an estimate — ask your provider directly if they don’t hand you one. You’re eligible if you schedule care at least 3 business days (Monday through Friday) in advance, and a provider or facility must also give you an estimate when you request it, whether or not you scheduled anything (CMS: Know your medical bill rights when not using insurance; CMS: Providers, payment resolution with patients).
The regulation sets four delivery clocks (45 CFR Part 149, Subpart G):
| How you triggered it | Provider’s deadline | Cited at |
|---|---|---|
| Scheduled at least 3 business days before the service | Not later than 1 business day after scheduling | § 149.610(b)(1)(vi)(A) |
| Scheduled at least 10 business days before the service | Not later than 3 business days after scheduling | § 149.610(b)(1)(vi)(B) |
| You requested it | Not later than 3 business days after the request | § 149.610(b)(1)(vi)(C) |
| Scope of care changed | New estimate no later than 1 business day before the service | § 149.610(b)(1)(vii) |
The estimate must be written, on paper or electronically in the method you requested. Electronic estimates must be something you can save and print, and a provider may describe the contents orally but must still issue it in writing (45 CFR Part 149, Subpart G). You won’t get an estimate during emergency care (CMS: Know your medical bill rights when not using insurance). If providers change less than 1 business day before your service, the replacement provider must accept the replaced provider’s estimate as its own.
One provider, one estimate
CMS states that estimates “only list expected charges for a single provider or facility, even if multiple providers will be involved in your care,” and advises requesting one from each provider and the facility. Its worked example: for surgery, request 2 estimates — one from the surgeon, one from the hospital (CMS: Know your medical bill rights when not using insurance).
There is a wrinkle worth knowing. The regulation’s content requirements say a good faith estimate must include an itemized list “grouped by each provider or facility,” including co-providers and co-facilities (§ 149.610(c)(1)(iii)). The consumer page and the regulation describe the scope differently, and the sources do not explain why. Practical approach: request a separate estimate from every provider and facility, and keep each one.
Photograph what you receive. If you lose it, an estimate is part of the patient’s medical record and copies issued within the last 6 years must be provided on request (§ 149.610(f)(1)). CMS publishes a blank good faith estimate example. The rule that matters most: you can’t use the dispute process without an estimate.
| What to check | Good faith estimate | Final bill |
|---|---|---|
| What it is | Expected charges before care; “isn’t a bill” | What you actually owe |
| Who it covers | One provider or facility per estimate | Bills can arrive from several providers |
| Legal weight | ”Not a contract” disclaimer required (§ 149.610(c)(1)(xi)) | The initial bill starts the 120-day clock |
| What it unlocks | A written estimate is required to dispute | At least $400 over that provider’s estimate opens the route |
Step 2: Read the estimate like an auditor
A compliant estimate must carry specific content (45 CFR Part 149, Subpart G):
- Patient name and date of birth (§ 149.610(c)(1)(i)).
- A clear description of the primary item or service, and its scheduled date if applicable (§ 149.610(c)(1)(ii)).
- An itemized list of expected items or services, grouped by each provider or facility (§ 149.610(c)(1)(iii)).
- Applicable diagnosis codes, expected service codes, and expected charges for each item or service (§ 149.610(c)(1)(iv)).
- Name, National Provider Identifier, and Tax Identification Number of each provider or facility, plus the State(s) and location(s) where care will be furnished (§ 149.610(c)(1)(v)).
CMS adds that expected charges should include facility and hospital fees (CMS: Know your medical bill rights when not using insurance). Then read the disclaimers, because they set expectations before anything goes wrong:
- Items or services requiring separate scheduling, with a disclaimer directly above that list (§ 149.610(c)(1)(vi)).
- A warning that additional recommended items or services may not be reflected in the estimate (§ 149.610(c)(1)(viii)).
- A warning that the figures are only an estimate and actual items, services, or charges may differ (§ 149.610(c)(1)(ix)).
- Your right to initiate patient-provider dispute resolution if billed charges are substantially in excess of the estimate, with where to find instructions and a statement that initiating it “will not adversely affect the quality of health care services furnished” (§ 149.610(c)(1)(x)).
- A statement that the estimate is not a contract and does not require you to obtain services from the listed providers (§ 149.610(c)(1)(xi)).
Item (vii) is “[Reserved]” in the regulation. Your provider should include everything they can, but you may need care they didn’t anticipate, and it won’t appear on the estimate (CMS: Know your medical bill rights when not using insurance). Unanticipated care is exactly the gap that can leave a bill standing.
Step 3: Do the $400 math
The comparison is per provider. CMS puts it plainly: if a bill from one of your providers is at least $400 more than the estimate from that provider, you can dispute (CMS: Medical bill rights; CMS: Know your medical bill rights when not using insurance). So if a surgeon billed $1,500 against a $900 estimate and the hospital billed $2,000 against a $1,850 estimate, only the surgeon bill clears the line. Subtract one provider at a time, against that provider’s own estimate.
The regulation uses different words for the same test, and it prints the bridge. Eligibility turns on billed charges being “substantially in excess” of the expected charges for that provider (§ 149.620(b)(1)), and § 149.620(a)(2)(ii) defines the phrase: “an amount that is at least $400 more than the total amount of expected charges listed on the good faith estimate for the provider or facility.” The $400 figure on CMS’s consumer pages is that regulatory definition, not a separate rule of thumb.
What the sources don’t tell us
- No source explains why the threshold is $400; the regulation simply defines “substantially in excess” as at least $400 over the expected charges (§ 149.620(a)(2)(ii)).
- No source prints how many disputes are filed, how often they are decided for the patient, how long they actually take, or the average amount at stake. We won’t estimate any of those.
- No source says whether the $25 fee is waived or reduced for hardship.
Step 4: File within 120 days and pay the $25
Start a dispute within 120 days (about 4 months) of getting your initial bill; CMS’s own instruction is “It’s important not to delay.” The regulation frames it as an initiation notice postmarked within 120 calendar days of receiving the initial bill (45 CFR Part 149, Subpart G).
Bring three things (CMS: Dispute a medical bill): your good faith estimate (plus your provider’s contact information), your bill, and the $25 non-refundable administrative fee. One instruction to respect: don’t mail any original documents.
The process doesn’t start until the fee is paid. Pay online by credit card, PayPal, or Venmo, or by mail with a money order or cashier’s check if you file by mail. Cash and personal checks aren’t accepted. Two channels: the federal portal at nsa-idr.cms.gov/billdisputes (email address and one-time PIN required), or the Billing Dispute Initiation Form by mail or fax. Forms reset after 15 minutes of inactivity, so have your documents open before you start typing.
Two protections before you file: “No matter the outcome, your costs won’t increase if you dispute your bill,” and if the dispute is decided in your favor the $25 is deducted from what you owe.
What happens after you file
An independent third party reviews the bill and determines an appropriate payment. The provider is asked for the estimate it gave you, the bill it sent, and any documents explaining why the bill is higher (CMS: Providers, payment resolution with patients).
The printed deadlines are narrow. The entity’s determination is due not later than 30 business days after receipt of the information described in § 149.620(f)(2)(i) (45 CFR Part 149, Subpart G). There is a clock on the provider too: within 10 business days of receiving the selection notice, the provider or facility must submit the estimate it gave you, the bill, and supporting documents (§ 149.620(f)(2)(i)). And if the reviewer finds your initiation notice incomplete or the service ineligible, you get 21 calendar days to submit supplemental information (§ 149.620(c)(4)).
Where the final amount is lower than the billed charges, the entity must reduce the total by the administrative fee you paid (§ 149.620(f)(3)(C)). It then notifies both provider and patient — no notification deadline is printed in the sources.
The three ways it ends
Ending one: the bill stays as-is. If the extra care was unplanned but appropriate, CMS says the bill is left as it is (CMS: Dispute a medical bill). This is a real documented outcome, not a process failure.
Ending two: the provider must reduce your bill. If the costs should have been foreseeable, or the services weren’t medically necessary, “your provider must reduce your bill.”
Ending three: you settle before the process ends. You and the provider can settle at any point before a determination. The provider must then reduce your bill by at least $12.50 (half of the $25 fee) and notify the reviewer, using the Payment Settlement Form.
On that notification window the two CMS sources differ and we won’t paper over it: the provider page says “as soon as possible, but no later than 3 days after the settlement,” while § 149.620 says “no later than 3 business days after the date of the agreement,” with the notice containing at minimum the settlement amount, the date, and documentation that both sides agreed (CMS: Providers, payment resolution with patients; 45 CFR Part 149, Subpart G). Fee allocation follows the same regulation: you pay at initiation; a non-prevailing provider pays an amount equal to the fee as a reduction; on settlement the provider pays half (§ 149.620(g)(1)).
Your protections while the dispute is open
While you’re disputing a bill, your provider or facility can’t (CMS: Dispute a medical bill; CMS: Providers, payment resolution with patients):
- Move your bill into collections, or threaten to.
- Collect existing late fees on unpaid bills until the dispute ends.
- Take action against you because you’re disputing.
If your bill is already in collections, the provider must stop pursuing payment until the dispute is resolved. And the fourth protection is the one people ask about most — retaliation: the estimate itself must state that initiating the process “will not adversely affect the quality of health care services furnished” (§ 149.610(c)(1)(x)).
These protections matter because collection activity is common: among adults with medical debt, 35.2 percent reported being contacted by a collection agency and 21.7 percent said the debt lowered their credit score (Urban Institute). If a collector or credit report is the problem rather than the bill, that’s a separate route: file with the Consumer Financial Protection Bureau at consumerfinance.gov/complaint or call 1-855-411-2372.
If you don’t qualify: the backup routes
No written estimate means no federal dispute process. CMS’s guidance there is to find an action plan and submit a complaint reporting a No Surprises Act violation (CMS: Know your medical bill rights when not using insurance).
Complaints go to the No Surprises Help Desk at 1-800-985-3059, with support 7 days a week in English, Spanish, and more than 350 other languages (CMS: Submit a provider or insurer complaint; CMS: Medical bill rights). The Help Desk reviews complaints for compliance and can refer them to another federal or state enforcement authority. If it needs more information it will get in touch within 60 days by your preferred contact method, and its form also resets after 15 minutes; the questions it asks are published as a plain list.
If a dispute was decided in your favor but the provider keeps billing or collecting, CMS’s instruction is the same: submit a complaint to the Help Desk.
| Your situation | Route | What you need | Cost | Key deadline |
|---|---|---|---|---|
| Bill at least $400 over your estimate | Patient-provider dispute resolution | Written estimate, bill, provider contact info | $25 non-refundable | Start within 120 calendar days of the initial bill |
| No written estimate | No Surprises Help Desk complaint | Your bill and the facts | None stated | Help Desk follows up within 60 days if it needs more information |
| You used your health insurance | Not eligible to dispute a bill | — | — | Use complaint and appeal routes instead |
| Bill tied to an unmet deductible | Not a No Surprises Act violation | — | — | — |
| Collector or credit-report problem | CFPB complaint | Your records | None stated | — |
| Dispute won but billing continues | No Surprises Help Desk complaint | Your determination and the bill | None stated | — |
Frequently asked questions
I never got a good faith estimate — can I still dispute the bill?
No. “You can’t use the No Surprises Act dispute process without an estimate.” Your route is the action plan and a Help Desk complaint at 1-800-985-3059.
Do I get the $25 back if I win? What if I lose?
If the dispute is decided in your favor, the $25 is deducted from what you owe. If it isn’t, the fee is non-refundable and the bill stands. Either way, CMS states that “no matter the outcome, your costs won’t increase if you dispute your bill.”
Will disputing send me to collections or wreck my care?
No. While the dispute is open the provider can’t move the bill to collections or threaten to, can’t collect existing late fees, and can’t act against you for disputing. If the bill is already in collections, collection activity must stop until the dispute resolves. The estimate itself must state that initiating the process won’t adversely affect your care.
I have insurance but paid cash for this service — do I qualify?
Possibly. Self-pay includes choosing not to use insurance when the service isn’t covered or paying out of pocket is cheaper. But you must not have used insurance for the care, and you must have told the provider in advance. If you used insurance, you don’t qualify to dispute a bill.
My bill is only $250 over the estimate — is it worth filing?
The consumer threshold is at least $400 over that provider’s estimate, so a $250 gap doesn’t open this route — and that threshold is the regulatory definition of “substantially in excess” (§ 149.620(a)(2)(ii)), not merely consumer guidance. You can still complain to the Help Desk.
How long does the whole thing take?
Only the printed deadlines: 120 calendar days to start; 30 business days for the entity’s determination after it receives the required information; a settlement notification within 3 business days under the regulation (CMS’s provider page says 3 days). No source gives real-world durations, so we won’t estimate one.
Can I settle with the provider mid-dispute?
Yes. You can settle before a determination. The provider must reduce your bill by at least $12.50 and notify the third-party reviewer.
The Bottom Line
With a written good faith estimate and a bill at least $400 above it, patient-provider dispute resolution is a real federal process with a known price ($25), a hard window (120 calendar days), and real protections while it runs: no collections, no threats, no late fees, no retaliation, and a written promise that your care won’t be affected. For a bill that overshot a written estimate by hundreds of dollars, using it is a reasonable move.
Be clear-eyed about what it isn’t. It is not a discount program. The reviewer can leave the bill exactly where it is — one of the three documented endings, and the one that applies when extra care was unplanned but appropriate. “Your costs won’t increase” is a floor, not a promise of savings. And with no written estimate, the dispute route doesn’t exist for you; your path is the Help Desk complaint.
The sources behind this guide print no dispute counts, no win rates, and no typical dollar amounts. Anyone who tells you what this process “usually” produces is going beyond the documentation.
How This Guide Was Built
This is a documentation-based guide, assembled from CMS’s consumer pages — Medical bill rights, Know your medical bill rights when not using insurance, Dispute a medical bill, and Submit a provider or insurer complaint — CMS’s provider-facing page on payment resolution with patients, the federal regulation at 45 CFR Part 149, Subpart G (§§ 149.610 and 149.620), the Urban Institute’s analysis of December 2025 Well-Being and Basic Needs Survey data (Urban Institute), and the KFF Health Care Debt Survey.
No calls were placed and no hands-on testing was done. We did not file a dispute, contact a hospital, or submit a form to test the portal; every statement comes from the published documents as written, and every deadline is reproduced as printed rather than smoothed into something vaguer.
Where the sources are truncated or inconsistent, the tension is left visible: “3 days” on CMS’s provider page versus “3 business days” in the regulation for the settlement notice, and the consumer page’s “single provider or facility” framing versus § 149.610(c)(1)(iii)‘s “grouped by each provider or facility.”
This is general information, not legal advice, and not a substitute for advice about your own situation.