Where you file a medical bill complaint depends on whether the problem is with your insurance company's handling of a claim, a provider's billing practices, or surprise billing. Different agencies handle each type: state insurance commissioners oversee insurance claims, state attorneys general investigate provider billing disputes, and the Centers for Medicare & Medicaid Services (CMS) handles Medicare complaints and surprise bill violations. Most billing problems can be resolved through channels that do not require an attorney. The path from complaint to resolution varies by insurance type and issue, but all states maintain at least two complaint mechanisms—one for insurance practices and one for provider billing.
Table of Contents
- Insurance Company Billing Complaints
- Provider Billing Disputes
- Medicare Billing Complaints and Appeals
- Balance Billing and Dispute Resolution
- Starting Your Complaint
- Frequently Asked Questions
Insurance Company Billing Complaints
If your insurance company denied a claim, mishandled your bill, or failed to pay a provider correctly, file a complaint with your state's insurance commissioner. The National Association of Insurance Commissioners (NAIC) operates a consumer portal where you select your state to access its department of insurance complaint page, which accepts complaints about insurers' claims handling and billing decisions.
Insurance regulators investigate whether carriers violated state laws, denied coverage improperly, or delayed payment. A complaint triggers a formal investigation with a deadline for the insurer to respond. Document the dates you submitted claims, copies of the denial letters, and any correspondence with the carrier. Include your policy number and a clear explanation of what went wrong.
Provider Billing Disputes
If a hospital or doctor's office billed you incorrectly—charging you for services you did not receive, applying the wrong rate, or violating your insurance coverage—file a complaint with your state's attorney general. Every state's attorney general operates a consumer protection division that investigates medical billing disputes.
Maryland's Health Education and Advocacy Unit, for example, handles billing disputes with providers and can be reached at 410-576-6571. Providers' billing disputes are handled differently than insurance company complaints because the problem is the facility or doctor's conduct, not the insurance company's processing. Attorneys general can investigate overcharging, balance billing (when a provider bills you for the difference between their charge and what insurance paid), and billing for services not rendered.
Medicare Billing Complaints and Appeals
Medicare beneficiaries can report No surprises Act violations and billing problems to CMS's federal helpline at 1-800-985-3059. The No Surprises Help Desk accepts complaints about surprise bills, balance billing, and noncompliance with surprise billing protections, and can refer cases to federal or state agencies for enforcement.
If you disagree with how Medicare or your Medicare Advantage plan handled a claim, you can appeal. Original Medicare (Fee-for-Service) billing disputes follow a five-level federal appeals process managed by Medicare Administrative Contractors and qualified independent contractors, with escalation to federal review and ultimately federal court if needed. For free help understanding your Medicare rights and navigating appeals, use your State Health Insurance Assistance Program (SHIP), which provides Medicare counseling and advocacy without attorney fees.
Balance Billing and Dispute Resolution
Under the No Surprises Act, if an out-of-network provider or emergency service billed you more than you expected to pay, you can use independent third-party dispute resolution. An independent reviewer determines appropriate payment amounts when you contest a bill, with a $25 non-refundable administrative fee. This option applies to balance billing disputes and allows you to challenge bills without litigation.
Some complaints cross jurisdictions. If your employer offers a self-insured health plan (common at large companies), state insurance regulators cannot enforce complaints—those plans fall under federal ERISA rules instead. You must appeal through your employer's plan administrator or contact the U.S. Department of Labor.
Starting Your Complaint
Before filing a formal complaint, request an itemized bill from the hospital billing department, which must provide it within 30 days of written request. The itemized bill shows exactly which services were billed and allows you to spot errors. Many hospitals employ patient advocates who can escalate complaints; if your facility has one, start there.
For your formal complaint, file in writing with the relevant agency—insurance commissioner, attorney general, or CMS—and cite specific line-item errors. Keep copies of all bills, insurance correspondence, and your written complaints. Send copies to both the state agency and your insurance carrier's appeals office. Document dates and names of anyone you speak to by phone.
Frequently Asked Questions
Can I file a complaint with both my state insurance commissioner and my state's attorney general?
Yes. If a billing problem involves both your insurance company's handling and a provider's billing practices, you can file separate complaints with each agency. Coordinate your documentation so each agency understands its role.
How long does a state insurance commissioner investigation take?
Most states require insurers to respond to complaints within 30 days, but the full investigation can take 60 to 120 days. Contact your state insurance department for its specific timeline.
What if the billing problem happened years ago?
State statutes of limitations vary. Insurance commissioner complaints typically must be filed within one to three years of the incident. Contact your state insurance department about older bills.
Do I need a lawyer to file a complaint?
No. State insurance commissioners, attorneys general, and SHIPs handle complaints at no cost to you. Hiring a lawyer is optional and usually unnecessary for complaints under $5,000.