Washington Billing Reference

Medical Billing in Washington: Payer Landscape, Medicaid & Timely Filing

The working reference for Washington billing teams: who the payers are, how Apple Health managed care is structured, and the filing windows that govern your claims. Updated July 2026.

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Medical Billing in Washington: The Short Version

Washington's Apple Health delivers Medicaid through five managed care organizations with county-based assignments, while the commercial market is anchored by two independent regional Blues — Premera Blue Cross and Regence BlueShield — that are entirely separate companies. Seattle's tech economy makes self-funded ERISA plans an outsized share of the commercial mix.

Payer Landscape

Major Payers in Washington

Payer	Type	What Billing Teams Should Know
Premera Blue Cross	Commercial / Blue plan	Largest WA commercial payer; also serves Alaska
Regence BlueShield	Commercial / Blue plan	Separate company from Premera; Cambia family
Kaiser Permanente Washington	Integrated HMO	Former Group Health; closed-network dynamics
UnitedHealthcare	Commercial / MA	Tech-employer self-funded administration
Aetna / Cigna	Commercial	Large ASO books for Seattle tech employers
Apple Health (HCA)	Medicaid	County-based MCO assignment

Medicaid Structure

Apple Health: Managed Care Plans

Administered by the Washington State Health Care Authority (HCA). The patient's plan assignment — not just Medicaid eligibility — determines the portal, prior-auth list, and filing rules that apply.

Plan	Notes
Molina Healthcare of Washington	Largest Apple Health plan
Coordinated Care (Centene)	Statewide presence incl. foster care contract
Community Health Plan of Washington	Community health center-founded nonprofit
UnitedHealthcare Community Plan	Statewide presence
Wellpoint Washington (Elevance)	Formerly Amerigroup WA

Filing Deadlines

Timely Filing Limits for Washington Claims

Initial-claim windows for the payers Washington practices bill most. Commercial limits are contract-specific — always confirm against your provider agreement and the payer's current manual.

Payer	Timely Filing Limit	Notes
Apple Health (WA Medicaid)	365 days from date of service	MCO contract windows may be shorter
Medicare (original)	12 months from date of service	Set by federal law; no contract variation
UnitedHealthcare (commercial)	90 days from date of service	Contract-specific; some plans allow 180
Aetna (commercial)	120 days from date of service	Contract-specific; verify provider agreement
Cigna (commercial)	90 days from date of service	Contract-specific; verify provider agreement
Humana (commercial)	90 days from date of service	Among the strictest; Medicare Advantage differs

Verified against payer publications at time of writing (July 2026). Filing limits change by contract and plan year — treat this table as a starting point, not a substitute for the payer manual. See our methodology.

WA-Specific Rules

Washington Billing Realities to Know

Two Independent Blues

Premera and Regence split the Blue brand in Washington as separate companies — separate credentialing, portals, fee schedules, and filing rules.

Tech ERISA Density

Self-funded tech-employer plans (administered by national carriers) follow plan documents, not state mandates — benefits and appeal rules vary plan by plan.

Kaiser WA Legacy

Kaiser’s acquisition of Group Health left legacy product lines; network status can differ between Kaiser WA products.

Balance Billing Protection Act

Washington’s state surprise-billing law works alongside the federal No Surprises Act for state-regulated plans.

Frequently Asked Questions

Apple Health allows 365 days from date of service for initial claims, administered by the Washington State Health Care Authority (HCA). Managed care plans operating in Washington may apply shorter contractual windows, so always verify each plan's provider manual.

Molina Healthcare of Washington, Coordinated Care (Centene), Community Health Plan of Washington, UnitedHealthcare Community Plan, Wellpoint Washington (Elevance). Each plan maintains its own provider portal, prior authorization list, and claim submission rules — the patient's plan assignment, not just Medicaid status, determines how a claim must be billed.

Premera Blue Cross, Regence BlueShield, Kaiser Permanente Washington, UnitedHealthcare, Aetna / Cigna, alongside Medicare and Apple Health. See the payer landscape table on this page for what billing teams should know about each.

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