Ohio Billing Reference

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

Ohio Medicaid covers 90%+ of beneficiaries through 5 plans: Aetna Better Health, Buckeye Health Plan, CareSource, Molina Healthcare, and UnitedHealthcare. Ohio launched a new Medicaid EDI platform in 2023 that required provider re-enrollment and updated 835/837 transaction mapping. Timely filing is 12 months for Medicaid.

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Medical Billing in Ohio: The Short Version

Ohio rebuilt its Medicaid managed care program as "Next Generation" with seven plans and a centralized fiscal intermediary — meaning claims flow through ODM's single front door before reaching plans. CareSource, headquartered in Dayton, is the state's Medicaid heavyweight. The commercial market pairs Anthem with strong regional payer Medical Mutual of Ohio.

Payer Landscape

Major Payers in Ohio

Payer	Type	What Billing Teams Should Know
Anthem BCBS of Ohio	Commercial / Blue plan	Largest commercial payer statewide
Medical Mutual of Ohio	Regional commercial	Ohio-only payer with major employer share; distinct credentialing
UnitedHealthcare	Commercial / MA	Statewide employer and MA book
Aetna	Commercial / MA	Employer and growing MA presence
Humana	Medicare Advantage	Significant MA share
Ohio Medicaid (ODM)	Medicaid	Single front-door claims submission via ODM fiscal intermediary

Medicaid Structure

Ohio Medicaid (Next Generation): Managed Care Plans

Administered by the Ohio Department of Medicaid (ODM). The patient's plan assignment — not just Medicaid eligibility — determines the portal, prior-auth list, and filing rules that apply.

Plan	Notes
CareSource	Largest Ohio Medicaid plan; Dayton-headquartered nonprofit
Anthem Blue Cross and Blue Shield	Statewide Next Generation plan
Buckeye Health Plan (Centene)	Statewide presence
Molina Healthcare of Ohio	Statewide presence
UnitedHealthcare Community Plan	Statewide presence
AmeriHealth Caritas Ohio	Newer entrant under Next Generation
Humana Healthy Horizons Ohio	Newer entrant under Next Generation

Filing Deadlines

Timely Filing Limits for Ohio Claims

Initial-claim windows for the payers Ohio 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
Ohio Medicaid	365 days from date of service	Generous window, but managed care plan secondary rules still apply
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.

OH-Specific Rules

Ohio Billing Realities to Know

Single Front Door Claims

Under Next Generation, claims submit through ODM’s centralized intermediary rather than directly to each MCO — rejections at the front door never reach the plan, so clearinghouse reports need daily review.

CareSource Scale

CareSource’s dominance means its PA list and policy updates affect more Ohio Medicaid revenue than any other single document.

Medical Mutual Contracts

Ohio practices often overlook that Medical Mutual is a full separate contract — not a Blue affiliate — with its own fee schedule and appeal process.

Seven-Plan Fragmentation

Seven Medicaid plans means seven PA lists. Centralized claims did not centralize prior authorization.

Frequently Asked Questions

Ohio Medicaid (Next Generation) allows 365 days from date of service for initial claims, administered by the Ohio Department of Medicaid (ODM). Managed care plans operating in Ohio may apply shorter contractual windows, so always verify each plan's provider manual.

CareSource, Anthem Blue Cross and Blue Shield, Buckeye Health Plan (Centene), Molina Healthcare of Ohio, UnitedHealthcare Community Plan, AmeriHealth Caritas Ohio, Humana Healthy Horizons Ohio. 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 Ohio, Medical Mutual of Ohio, UnitedHealthcare, Aetna, Humana, alongside Medicare and Ohio Medicaid (Next Generation). See the payer landscape table on this page for what billing teams should know about each.

CareSource is a Dayton, Ohio-based nonprofit MCO and consistently the largest Ohio Medicaid managed care plan by enrollment. Unlike national MCOs, CareSource is Ohio-headquartered with deep statewide penetration — for most Ohio providers, CareSource claims volume exceeds any other single Medicaid MCO. Ohio Medicaid Next Generation's other active MCOs include Buckeye Health Plan (Centene), Molina Healthcare of Ohio, Aetna Better Health of Ohio, and UnitedHealthcare Community Plan of Ohio. CareSource credentialing, portal access, and prior authorization familiarity should be a first-priority setup for any Ohio practice accepting Medicaid patients.

Code Reference

Common Codes Billed in This State

Frequently billed codes in this state’s payer environment, with notes on state-specific rules and common denial patterns.

Code	Description	State-Specific Note
99213	Office visit, est. patient — level 3	Ohio Medicaid 5-plan MCO system; verify member’s assigned plan
99214	Office visit, est. patient — level 4	CareSource and Buckeye require separate provider portals
99215	Office visit, est. patient — level 5	New EDI system (2023): verify 837/835 mapping is updated
Mod. GT	Telehealth — real-time audio/video	Ohio Medicaid allows; verify per MCO after 2023 EDI migration
G0438	Annual wellness visit — initial	High MA penetration in Columbus and Cleveland metros
CO-16	Claim lacks required information	Most common denial post-2023 EDI migration; re-check NPI/taxonomy mapping

Codes and reimbursement rates change annually. Verify current fee schedules with each payer before billing. Full code lookup →