Washington PIP Medical Bill and Review Guide

Direct answer

Washington auto insurers must offer personal injury protection, but the named insured may reject it in writing. When PIP applies, medical and hospital benefits cover reasonable and necessary accident-related expenses incurred within three years, subject to the purchased limit and policy terms. If an insurer relies on a health professional to deny, limit, or terminate those benefits, WAC 284-30-395 requires a meaningful written explanation and a review by an appropriately credentialed professional in the same health field or specialty.

A provider should not assume that every Washington auto policy contains PIP or that an injured patient has the same limit. Coverage may have been rejected, the basic or higher option may have been purchased, benefits may be exhausted, or the claimant may qualify under a different insured status. Verification should occur before the account is managed as a PIP receivable.

This guide summarizes Washington statutes, rules, and Office of the Insurance Commissioner information available October 1, 2026. It is an operational overview, not a determination of coverage, medical necessity, causation, assignment rights, priority, exhaustion, or remedies in a particular claim.

Washington PIP framework

Issue	Washington rule	Provider control
Offer and rejection	The insurer must offer PIP; the named insured may reject it in writing	Obtain the declarations and written coverage position
Basic medical limit	The statutory minimum offer includes $10,000 in medical and hospital benefits	Confirm the actual purchased limit and remaining balance
Higher medical limit	The insurer must also offer an option with $35,000 in medical and hospital benefits	Do not infer the limit from the claim number or carrier
Covered expense	Reasonable and necessary accident-related medical and hospital expense	Connect diagnosis, treatment plan, and service to the collision
Time window	Covered expense must be incurred within three years of the accident	Calendar the accident date and service cutoff
Medical review	A medical-opinion denial, limit, or termination triggers WAC 284-30-395 standards	Request the actual rationale and pertinent documents

1. Verify that PIP exists

RCW 48.22.085 requires an insurer issuing a new or renewal automobile liability policy to offer PIP. The named insured may reject PIP in writing, and that rejection binds all levels of coverage and all persons insured under the policy until the named insured later requests coverage in writing. A verbal statement that the policy has no PIP is not a substitute for a documented coverage determination.

Policy number, effective dates, vehicle, named insured, and claim number.
Declarations showing whether PIP was purchased and at what limit.
Written rejection or endorsement if the carrier says PIP is absent.
The claimant's status as named insured, resident relative, occupant, permissive user, or pedestrian.
Other applicable auto policies and any coordination or priority issue.
Benefits paid, pending reserves, remaining limit, and exhaustion position.

2. Confirm the claimant fits the statutory definition

RCW 48.22.005 defines an insured for PIP purposes to include the named insured and resident relatives, and also a person who sustains bodily injury while occupying or using the insured automobile with permission or as a pedestrian struck by it. The exact status matters because policy language, exclusions, other coverage, and the facts of use can affect the result.

Document the collision date, location, vehicle, occupants, driver permission, household relationship, and pedestrian facts early. Inconsistent intake data can produce coverage delays that look like ordinary billing denials.

3. Know the medical-benefit limits and time window

Under RCW 48.22.095, the basic PIP offer includes up to $10,000 in medical and hospital benefits. RCW 48.22.100 requires the insurer to offer a higher option with up to $35,000 in those benefits. These are offer requirements; the patient's actual policy controls which limit applies.

RCW 48.22.005 describes medical and hospital benefits as reasonable and necessary expenses incurred for accident injuries, including services by licensed health professionals, pharmaceuticals, prostheses, eyeglasses, necessary ambulance, hospital, and nursing expenses. The expense must be incurred within three years after the accident, and PIP payments are limited to actual loss and expense incurred.

Three years is not a billing strategy

The statute's three-year treatment window addresses when expenses are incurred. It should not be treated as permission to delay billing, notice, documentation, or response to a carrier request. Submit clean claims promptly and preserve policy-specific deadlines.

4. Build a defensible medical-bill packet

Verify PIP coverage, claimant status, limit, and remaining benefits.
Use the exact accident date and claim identifiers on every submission.
Document the accident mechanism, symptoms, diagnosis, and treatment plan.
Explain why the service is reasonable, necessary, and related when the connection is not self-evident.
Validate codes, modifiers, units, dates, provider credentials, and itemization.
Attach records proportionate to the service and any requested information.
Capture delivery, acknowledgement, payment, EOB, and follow-up dates in one audit trail.

The clinical record should support the elements the statute makes relevant: injury from the automobile accident, necessity, reasonableness, and timing. Template language without patient-specific findings is weaker than a clear history, examination, assessment, functional impact, treatment rationale, and response to care.

5. Distinguish coverage review from treatment review

A coverage denial may turn on the written rejection, policy dates, claimant status, vehicle use, exclusion, limit, or exhaustion. A treatment review examines whether medical and hospital services are reasonable, necessary, related to the accident, and incurred within three years. The evidence and response should match the actual ground rather than sending the same appeal packet for every denial.

Denial type	Records to obtain	Provider response focus
No PIP coverage	Declarations, written rejection, endorsements, coverage letter	Policy and claimant status; refer unresolved coverage questions
Limit exhausted	Payment ledger, reserve or exhaustion notice, EOB history	Reconcile every payment and disputed line
Not accident-related	Review rationale, collision and prior-history records	Causation, onset, objective findings, and differential explanation
Not reasonable or necessary	Reviewer report and relied-on documents	Treatment plan, progress, function, alternatives, and clinical rationale
Outside three years	Accident and service dates	Correct date error or identify why the service falls within the statutory window

6. Apply WAC 284-30-395 to medical-opinion reviews

WAC 284-30-395 applies when an insurer relies on the medical opinion of a health care professional to deny, limit, or terminate PIP medical and hospital benefits. Before taking that action, the insurer must provide a written explanation of coverage and notice that benefits may be affected if services are not reasonable, necessary, related to the accident, or incurred within three years. The rule identifies those as the permitted grounds under the cited PIP statutes.

After the insurer concludes that it intends to deny, limit, or terminate benefits, it must provide the insured a written explanation within a reasonable time. The explanation must state the true and actual reason supplied by the consulted professional in clear, simple language. A bare statement that treatment is 'not reasonable or necessary' is insufficient. Pertinent documents must be provided on the insured's request.

The consulted professional must be currently licensed, certified, or registered in the same health field or specialty as the treating professional. When multiple professionals treat the patient, the principal prescribing or diagnosing provider's field or specialty controls unless the insured and insurer agree otherwise. The insurer must keep enough information in the claim file to verify the reviewer's credentials.

Effective-date note

The Washington Legislature page displays the current rule through October 17, 2026 and a revised version effective October 18, 2026. The operative medical-review, notice, same-specialty, and arbitration standards remain materially aligned, while the revised text expressly frames violations as unfair methods or practices. Recheck the official rule for services and actions after the effective date.

7. Respond to a denial with the actual record

Request the complete written rationale and the documents relied on.
Identify the reviewing professional, credentials, field, and specialty.
Compare the review with the treating provider's discipline and role.
Correct factual errors about the accident, symptoms, dates, prior history, or services.
Answer each stated ground with targeted clinical and billing evidence.
Reconcile the policy limit and payment ledger separately from medical necessity.
Preserve policy appeal, arbitration, complaint, contractual, and legal deadlines.

WAC 284-30-395 also sets minimum standards when the auto policy contains an arbitration provision: arbitration must begin within a reasonable period after the insured requests it, occur in the insured's county of residence or county of residence at the time of the accident unless otherwise agreed, use relaxed evidence rules unless the parties agree otherwise, and follow recognized or agreed arbitration rules. Whether a particular dispute is arbitrable depends on the policy and facts.

Washington PIP quality-control checklist

Declarations, written rejection, policy limits, and endorsements obtained.
Claimant's statutory insured status documented.
Accident date and three-year expense window calendared.
Benefits ledger and remaining limit reconciled.
Bills and records support reasonableness, necessity, and accident relationship.
Denial classified as coverage, exhaustion, coding, documentation, or treatment review.
Written rationale and relied-on documents requested.
Reviewer credentials and same-field or specialty requirement checked.
Response addresses each actual denial ground with specific evidence.
Any policy appeal, arbitration, complaint, or legal deadline preserved.

Related Millennova Legal resources

Use Millennova Legal's auto-accident reimbursement support and Washington auto-accident guide for broader claim context. Compare the Oregon PIP denial guide and Maryland PIP billing guide. Review the assignment-of-benefits and medical-liens guide before relying on a patient document as authority to collect or act.