Colorado Billing Reference

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

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

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Medical Billing in Colorado: The Short Version

Colorado structures Medicaid differently than most states: instead of full-risk MCOs, Health First Colorado uses Regional Accountable Entities (RAEs) that coordinate care while most physical health claims pay fee-for-service through the state — with behavioral health capitated through the RAEs. Kaiser Permanente's large closed-network presence and a strong state exchange (Connect for Health Colorado) round out a distinctive market.

Payer Landscape

Major Payers in Colorado

Payer	Type	What Billing Teams Should Know
Anthem BCBS of Colorado	Commercial / Blue plan	Largest commercial payer
UnitedHealthcare	Commercial / MA	Denver metro employer book; owns Rocky Mountain Health Plans
Kaiser Permanente Colorado	Integrated HMO	Major Front Range closed-network share
Cigna	Commercial	Employer self-funded presence
Rocky Mountain Health Plans	Regional	Western Colorado strength; UHC-owned but distinct products
Health First Colorado (HCPF)	Medicaid	RAE regions; physical health mostly FFS

Medicaid Structure

Health First Colorado: Managed Care Plans

Administered by the Department of Health Care Policy & Financing (HCPF). The patient's plan assignment — not just Medicaid eligibility — determines the portal, prior-auth list, and filing rules that apply.

Plan	Notes
Regional Accountable Entities (RAEs)	Care coordination + behavioral health capitation by region — physical health largely pays FFS through HCPF
Denver Health Medicaid Choice	One of two true managed care plans
Rocky Mountain Health Plans Prime	Western-slope managed care option

Filing Deadlines

Timely Filing Limits for Colorado Claims

Initial-claim windows for the payers Colorado 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
Health First Colorado	365 days from date of service	Interim claims rules apply for some provider types
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.

CO-Specific Rules

Colorado Billing Realities to Know

RAE Model ≠ MCO Model

Physical health claims mostly go FFS to the state while behavioral health is capitated through RAEs — billing teams must split workflows by service type, not just payer.

Behavioral Health Capitation

BH services bill the RAE’s behavioral health organization, with region-specific rules — a parallel system to physical health.

Kaiser Front Range Share

Kaiser’s density around Denver means out-of-network claim policy knowledge is required even for non-participating practices.

Mountain-Resort Seasonality

Resort-area practices see out-of-state and international payer mixes with heavy BlueCard and travel-insurance volume.

Frequently Asked Questions

Health First Colorado allows 365 days from date of service for initial claims, administered by the Department of Health Care Policy & Financing (HCPF). Managed care plans operating in Colorado may apply shorter contractual windows, so always verify each plan's provider manual.

Regional Accountable Entities (RAEs), Denver Health Medicaid Choice, Rocky Mountain Health Plans Prime. 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.

Anthem BCBS of Colorado, UnitedHealthcare, Kaiser Permanente Colorado, Cigna, Rocky Mountain Health Plans, alongside Medicare and Health First Colorado. See the payer landscape table on this page for what billing teams should know about each.

Colorado uses Regional Accountable Entities (RAEs) rather than full-risk MCOs. RAEs coordinate care and hold capitation for behavioral health, but most physical health claims still pay fee-for-service through HCPF. Practices bill the state for physical health and the RAE’s behavioral health organization for BH services — two parallel workflows.