How to Submit Out-of-Network Insurance Claims: Step-by-Step Guide
The correct process for submitting an out-of-network (OON) insurance claim depends on the health plan. Some plans accept out-of-network insurance claims submitted directly by the provider. Others require the patient to submit a claim for reimbursement. Some plans do not provide non-emergency OON benefits at all. The safest process, for both practices and patients, is to verify the plan’s OON benefits and submission instructions before the service is delivered, or as early in the process as possible. This guide covers the six-step framework most applicable to provider-submitted OON claims.
How Does Out-of-Network Insurance Work When a Claim Is Submitted?
When out-of-network insurance claims are submitted, the general sequence is: the provider or patient submits the claim to the plan; the plan reviews and adjudicates the claim according to its OON benefit terms; the plan issues an explanation of benefits (EOB) showing its payment decision, any adjustments, and the patient’s remaining responsibility; and the provider or patient follows up based on the EOB outcome. Each of those stages can vary by plan.
Step 1: Verify Out-of-network Insurance Benefits and Claim-Submission Rules
Before any other step, confirm the following with the plan:
- Whether the plan has OON benefits for this specific service
- Whether prior authorisation, a referral, or a network exception is required
- Who must submit the claim, the provider, the patient, or either
- The filing deadline for OON claims
- The required claim form, submission channel, and supporting documentation
- And whether payment can be assigned directly to the provider
Eligibility and benefits verification that confirms OON benefit terms before the service is covered in the eligibility guide.
Do not assume that because a plan covers in-network services at a given facility, it covers OON services from providers at that facility in the same way. Verify specifically for the provider and service type involved.
Step 2: Collect Accurate Patient, Plan, and Service Information
Accurate claim submission requires complete information from the start. Errors in demographics, member identification, or service details generate rejections that reset the submission clock and delay payment.
- Patient demographics: full legal name, date of birth, address.
- Member ID, group number, and plan contact details.
- Secondary insurance information if applicable.
- Provider identifiers: NPI, tax identification number, and specialty.
- Date, place, and type of service.
- Accurate diagnosis and procedure documentation.
Step 3: Prepare the Correct Claim or Member-Submission Package
The plan’s instructions control what is required. Some plans use standard electronic claim formats. Others require a paper claim form or a member-submitted reimbursement package. Confirm the plan’s preferred format, required form, and any payor-specific requirements before preparing the submission.
Documents Required for Out-of-Network Claims
Requirements vary by plan. Commonly requested documents may include:
- Completed payor or member claim form, if required.
- Itemised bill or superbill showing service date, provider details, CPT and diagnosis codes, and charges.
- Patient and plan identification details.
- Provider identifiers and service information.
- Proof of payment if the patient paid upfront and is seeking reimbursement.
- Authorisation, referral, or network-exception documentation if applicable.
- Clinical documentation if the payor requests it for medical necessity review.
Not every plan requires every document. Always verify the specific requirements with the payor before submitting.
Step 4: Submit to the Correct Payor Channel Before the Deadline
Submission channels for OON claims vary: payor portal, clearinghouse, direct mail, or a member reimbursement portal if the patient is submitting. Confirm the correct channel in Step 1. Regardless of channel, retain confirmation of submission, a copy of everything submitted, and the submission date.
Timely filing limits by payor are strict and non-negotiable, a claim submitted after the deadline cannot be appealed on the basis of late discovery.
Step 5: Review the EOB or Remittance Before Billing the Patient
The EOB is the plan’s record of how it processed the claim. It is not a patient bill. Before sending any statement to the patient, reconcile the EOB against the submitted claim: confirm the allowed amount, the plan’s payment, the patient’s responsibility under the plan, and whether any coordination of benefits or secondary insurance applies.
ERA and EFT in medical billing, including how electronic remittances are reconciled, is covered in the ERA and EFT guide.
Step 6: Respond to a Denial, Missing-Information Request, or Underpayment
If the claim is denied or returned for additional information, the first step is to identify the payor’s stated reason, the response deadline, and the evidence needed. Claim rejection vs claim denial are different situations with different responses, a rejection requires correction and resubmission, a denial requires an appeal or dispute process. Avoid assuming that a denial is final without reviewing the appeal rights and deadline specified in the EOB or payor’s remittance.
For underpayments, where the plan paid less than the plan’s own benefit terms require, submit a payment dispute with the EOB and the applicable plan documentation. Do not write off OON underpayments without first verifying the plan’s OON allowed amount method and whether a dispute right applies.
Common out-of-network Insurance Claims Mistakes That Delay Payment
Submitting a clean claim on the first attempt, with complete information, correct coding, and all required documentation, is the most effective way to reduce OON claim delays.
- Assuming a plan has OON benefits without verifying for the specific service.
- Missing the plan’s filing deadline.
- Sending the claim to the wrong channel or wrong payor address.
- Submitting with missing member, provider, or service information.
- Not retaining proof of submission or a copy of the claim.
- Billing the patient before reviewing the EOB and confirming the plan’s payment decision.
- Treating the EOB as a final patient bill without reconciling amounts.
- Ignoring applicable federal or state billing protections when determining what to bill the patient.
A3 Medical Billing Can Help with Out-of-network Insurance Claims
Accurate OON claim submission requires strong front-end verification, complete claim preparation, and proactive EOB reconciliation. A3 Medical Billing provides medical billing services and out-of-network claims support for independent practices, including benefit verification, OON claim preparation and submission, denial follow-up, and patient balance communication. Contact A3 to find out where your OON claim workflow needs strengthening.
Frequently Asked Questions
How do I submit an out-of-network insurance claim?
Verify the plan’s OON benefits and submission instructions first. Confirm who must submit, the provider or the patient, and what the filing deadline is. Prepare a complete claim or member-submission package with the required documentation. Submit to the correct payor channel and retain confirmation. Review the EOB before billing the patient. The Washington State Office of the Insurance Commissioner notes that OON providers may not bill the health plan directly, patients may need to request claim forms and due dates from their insurer and submit the claim themselves.¹
Can a provider submit an out-of-network claim for a patient?
It depends on the plan. Some plans accept provider-submitted OON claims directly. Others require the patient to submit a reimbursement claim. Some plans accept either. Verify the plan’s submission rules before preparing the claim, submitting to the wrong party delays payment and may require the patient to resubmit through the correct channel.
What documents are required for out-of-network claims?
Requirements vary by plan, but commonly requested documents include a completed claim or member reimbursement form, an itemised bill or superbill with service details and codes, patient and plan identification, provider identifiers, and proof of payment if the patient paid upfront. Clinical documentation may be required for medical necessity review. Always confirm the plan’s specific requirements before submitting.
How long do I have to file an out-of-network claim?
Filing deadlines vary by plan and are typically specified in the plan documents or confirmed during the benefits verification step. Missing the filing deadline generally means the claim cannot be paid, regardless of whether the service was covered and the claim was accurate. Confirm the OON filing deadline in Step 1, before the service is delivered where possible.
What should I do if an out-of-network claim is denied?
Identify the payor’s stated denial reason, the appeal deadline, and the evidence required to support an appeal. Distinguish a rejection, which requires correction and resubmission, from a denial, which requires an appeal or dispute process. Review the EOB carefully, confirm the plan’s appeal rights, and act within the deadline. For denials related to NSA-covered services, the federal independent dispute resolution process may be available.²
- Washington State Office of the Insurance Commissioner, How Your Health Insurance Claims Process Works. Washington State Office of the Insurance Commissioner. Accessed September 2026.
- Centers for Medicare and Medicaid Services, No Surprise Billing. Centers for Medicare and Medicaid Services, 2022. Accessed September 2026.
- Centers for Medicare and Medicaid Services, Provider Requirements and Resources. Centers for Medicare and Medicaid Services, 2022. Accessed September 2026.
