# What happens if a self-pay bill is $400 above the estimate?

Canonical: https://prospyrmed.com/resources/practice-answers/medical-bill-400-dispute
Sources reviewed: 2026-09-16 · Prepared by Prospyr

An eligible uninsured/self-pay patient may use the federal patient-provider dispute process when a provider’s billed charges are at least $400 above that provider’s good faith estimate. It is not an automatic refund rule or a $400 allowance. Check the current eligibility and filing instructions.

## Compare like with like

CMS evaluates the difference for the relevant provider or facility. Assemble the estimate the patient received, the itemized bill and the dates. Do not silently replace the original estimate after the bill arrives or add a new charge to make the discrepancy disappear.

Source: [CMS: Dispute a medical bill](https://www.cms.gov/initiatives/your-patient-rights/medical-bill-rights/get-help/dispute-medical-bill) — Federal patient-provider dispute process

## Respond through the applicable process

The patient’s insurance-use status and other requirements matter. Keep the record of any explanation, correction or resolution and follow current dispute instructions. Your internal review should investigate why the expected charges and final charges differ, even when a particular dispute route does not apply.

Source: [CMS: Dispute a medical bill](https://www.cms.gov/initiatives/your-patient-rights/medical-bill-rights/get-help/dispute-medical-bill) — Federal patient-provider dispute process

## Practical checklist

1. Retrieve the delivered estimate and itemized bill.
2. Compare the same provider’s expected and billed charges.
3. Check eligibility and current filing deadlines.
4. Assign an owner for patient communication and documented resolution.

## Worked example

An estimate shows $1,000 for one provider and that provider bills $1,450. The $450 difference warrants eligibility review for the federal process. It does not establish the outcome of a dispute, and it does not authorize the practice to increase every estimate by $399.

## Mistakes to avoid

- Treating $400 as a permitted unannounced surcharge.
- Comparing unrelated providers’ totals without checking the rules.
- Telling an eligible patient a signed payment policy removes dispute rights.

## Related questions

- [What should a med spa good faith estimate include?](https://prospyrmed.com/resources/practice-answers/good-faith-estimate-template)
- [When must a practice send a good faith estimate?](https://prospyrmed.com/resources/practice-answers/good-faith-estimate-deadlines)
- [Can one good faith estimate cover a treatment series?](https://prospyrmed.com/resources/practice-answers/recurring-treatment-estimates)

Prepared by Prospyr from the cited primary sources. These are educational workflow resources, not individualized clinical, coding, legal or tax advice. No clinician, certified-coder or attorney review is claimed. Confirm current code instructions, payer terms and applicable law for the actual service and date. CPT is a registered trademark of the American Medical Association; this is not a substitute for a licensed current code set.