Washington medical billing and payer rules

Timely filing in Washington medical billing and payer rules

Washington medical billing and payer rules surprise billing vs the federal NSA

Major payers

How does Apple Health (Washington Medicaid) billing work?

Washington Medicaid is called Apple Health and is run by the Washington State Health Care Authority (HCA). A claim goes one of two ways: fee-for-service, billed to HCA through its claims system called ProviderOne, or managed care, billed to the health plan the patient is enrolled in. HCA's ProviderOne Billing and Resource Guide (September 2025 edition) states that HCA does not process or pay claims for clients enrolled in a managed care plan for services under that plan's contract.

ProviderOne is the web portal for eligibility, claims, remittances and claim status. Read the managed care segment in the client benefit inquiry first: if a segment covers your dates of service, the claim belongs to the plan. If there is none, or it ended before the date of service, the client is fee-for-service and you bill ProviderOne.

HCA accepts only electronic claims for Apple Health, and has done so since October 1, 2016. Paper needs HCA approval and is allowed only when something outside the provider's control blocks electronic submission.

Facility claims go on the UB-04 and professional claims on the CMS-1500. Every performing provider must be enrolled under the billing provider's Core Provider Agreement, and HCA says enrollment starts no earlier than approval and it does not pay for services given while the application is pending. Our credentialing and enrollment service handles those applications.

Our Medicaid payer guide covers the national picture.

Which managed care plans does Apple Health use?

Apple Health managed care runs through managed care organizations (MCOs), which are licensed health insurance carriers under contract with HCA. Appendix C of the ProviderOne guide lists five: Wellpoint Washington (formerly Amerigroup), Community Health Plan of Washington (CHPW), Coordinated Care of Washington (CCW), Molina Healthcare of Washington and United Healthcare Community Plan. HCA marks the list as subject to change.

Integrated managed care, started in 2016, puts physical health, mental health and drug and alcohol treatment in one plan. The guide says it is now available in all regions, and ProviderOne shows it as fully integrated managed care (FIMC).

Each plan has its own portal, prior authorization rules and appeal windows, and HCA tells providers to follow the MCO's billing requirements. One case catches teams out: when an MCO plan is secondary, the guide says providers do not need to be in its network to bill it. Our Molina Healthcare payer guide covers one of the five plans in detail.

What is the Apple Health timely filing limit?

The initial Apple Health timely filing limit is 365 days from the date of service, according to HCA's ProviderOne guide and WAC 182-502-0150. The clock can also run from a final fair hearing decision, a court order, or delayed eligibility certification.

After a timely first claim, you can resubmit, modify or adjust it for 24 months from the date of service, with one exception: prescription drug claims get 15 months. The guide is blunt that ProviderOne does not process claim appeals. If a claim has any paid amount, you submit an adjustment. If it denied, you fix the reason and resubmit, and ProviderOne needs the transaction control number (TCN) of the original timely claim as proof.

The one-year exceptions need a remarks entry: "Managed care recoupment" with the date, or "primary payer" and "recoupment" with the date. HCA may also accept proof of extenuating circumstances.

The guide cited here states no managed care filing limit. Those limits sit in each MCO's provider manual or contract, so we load them per plan.

Who is the Medicare MAC for Washington?

The Medicare Administrative Contractor (MAC) for Washington Part A and Part B claims is Noridian Healthcare Solutions, LLC, in Jurisdiction F (JF). CMS's list of MACs by state shows JF covering Alaska, Arizona, Idaho, Montana, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming, so a Spokane practice and a Boise practice bill the same contractor.

Medicare's own filing limit is one calendar year after the date of service under 42 CFR 424.44, shown in the table above as 12 months. For a dual eligible patient, HCA wants the crossover claim within six months of the Medicare processing date, so we log that date when the remittance posts.

CMS also lists a separate MAC for durable medical equipment (DME D, also Noridian). Our Medicare payer guide explains the claim, appeal and enrollment steps.

What is Washington's prompt pay rule for health insurers?

Washington's prompt pay standards for health carriers sit in the Insurance Commissioner's rules, with WAC 284-170-431 covering the payment terms that must appear in provider contracts. We do not quote its day counts or interest rate here, so read the current text of that rule. The exact figures are on the Washington Legislature's code site, and our team reads them before it escalates any late claim.

The payer's clock starts when it receives a clean claim, so proof of receipt is the evidence. We keep the clearinghouse acceptance report (the 277CA) for every claim.

State prompt pay rules apply to plans the state regulates. Apple Health follows HCA's rules and the MCO contracts, Medicare follows federal rules, and self-funded employer plans follow their plan documents and federal ERISA claims rules. A late claim from a self-funded plan goes to the plan contract, not to a complaint with the Insurance Commissioner.

How does the Balance Billing Protection Act work next to the federal No Surprises Act?

Washington has its own surprise billing law for state-regulated health plans, the Balance Billing Protection Act (BBPA), in chapter 48.49 RCW with rules in chapter 284-43B WAC. The Office of the Insurance Commissioner (OIC) says the state law applies to state-regulated health plans and to state and school employee benefit plans.

The BBPA protects patients from bills by out-of-network hospitals and providers for emergency services, including behavioral health emergencies, and for non-emergency services by an out-of-network provider at an in-network hospital or ambulatory surgical center. Since January 1, 2025 it also covers ground ambulance services. The provider has to bill the health plan directly, and the patient's cost sharing is limited to what it would be in network and counts toward the deductible.

The plan owes the out-of-network provider or facility a commercially reasonable amount, based on payments for the same or similar services in a similar geographic area. The OIC says that if the two sides cannot agree within 30 days, either party can go to arbitration.

The OIC's arbitration page adds that in March 2026 it announced its intent to delay transition to the federal process for a minimum of two years, and that it will revisit the decision in 2028. For a fully insured claim in Washington, that means the BBPA arbitration path remains the one to plan around.

Self-funded plans are the other half of the picture. The federal No Surprises Act protects people in self-funded group health plans, and the OIC says an employer that self-insures and wants to offer more protection can opt in to follow Washington's law. The plan must tell the OIC at least 15 days before it intends to take part, and the OIC publishes a list of participating plans. Opt-in lasts a full year unless the plan renews automatically, and a third-party administrator must follow the law too.

So the first question on every out-of-network emergency or facility claim is the plan type. Fully insured goes down the BBPA path. A self-funded plan on the OIC's opt-in list also goes down the BBPA path. Any other self-funded plan goes through federal open negotiation, and under 45 CFR 149.510 either party can start federal IDR in the 4-business-day period after the 30-business-day open negotiation period ends. For the federal process, see out-of-network billing and IDR.

Under WAC 284-43B-040, insurers must have a way to tell a provider whether a patient's plan is subject to the BBPA. Use it before you choose a pathway.

What must Washington providers do under the BBPA?

Providers and facilities must post the OIC's consumer notice on their website and give it to consumers who ask, under WAC 284-43B-050. The OIC says they must also refund any overpayment within 30 business days and must not ask consumers to limit or give up their balance billing rights.

Enforcement is stepwise. If a provider keeps balance billing and the OIC sees a pattern of unresolved violations, it first gives the provider a chance to correct the behavior. If nothing changes, the OIC treats it as unprofessional conduct and refers the provider or facility to the Department of Health.

Which payers matter most for Washington hospitals?

For a Washington hospital or emergency department, the payers we plan around are Medicare under Noridian JF, Apple Health fee-for-service through ProviderOne, the five Apple Health managed care plans, and the commercial plans that sell fully insured and self-funded products. The commercial side is worked contract by contract.

Our Molina Healthcare guide covers one of the Apple Health plans. Patients cross state lines, so see our Oregon and Idaho pages for the neighboring rules.

What changes for Washington emergency departments?

Emergency departments feel both laws first. An out-of-network emergency group or facility in Washington sorts each underpaid claim by plan type, then follows the BBPA path or federal open negotiation and IDR. Ground ambulance claims for dates of service on or after January 1, 2025 are now part of the BBPA.

Our emergency medicine billing page covers the professional side, and our hospital and facility billing service covers the UB-04 claim.

What should a Washington billing office check before a claim goes out?

Check five things on every Washington claim: payer on the date of service, filing clock, plan type, form, and proof of delivery.

1. Run eligibility in ProviderOne for Apple Health patients and read the managed care segment: a plan on the date of service means the claim goes to that plan, not to HCA.
2. Write the filing deadline on the account at registration: 365 days for Apple Health fee-for-service, six months from the Medicare processing date for crossover, and the plan's own limit for an MCO or commercial payer.
3. For any out-of-network emergency or facility claim, record the plan type and whether the plan is on the OIC's list of self-funded plans that opted in to the BBPA.
4. Bill the UB-04 for facility claims and the CMS-1500 for professional claims, with the attending, operating and other provider NPIs on institutional claims.
5. Save the clearinghouse acceptance report and the ProviderOne TCN so a later resubmission can prove the first claim was timely.

Work the aged list by nearest deadline, not by balance.

How we handle billing in Washington

For Washington clients we sort every claim on day one into Medicare under Noridian JF, Apple Health fee-for-service, an Apple Health plan, fully insured commercial, or self-funded. That sort decides the filing clock and, for out-of-network claims, whether the dispute goes to BBPA arbitration or to federal IDR.

Claims go out within 24 hours of charge entry and denials are worked within 48 hours. We track the Apple Health 365-day, 24-month and crossover six-month dates on the account. To talk through your Washington payer mix, book a call.