August 14, 2026

Medicaid MCO Behavioral Health Carve-Outs: State Variation Billing Guide

At Revenant Care Group, we work with approximately 50 behavioral health practices across the country, and the single most consistent source of preventable revenue loss we see right now is not documentation or coding. It is the failure to correctly identify whether a Medicaid enrollee’s behavioral health benefit is carved in to the managed care organization or carved out to a separate specialty plan. That determination changes the payer, the fee schedule, the prior authorization pathway, and sometimes even the credentialing requirement. Getting it wrong means a clean claim going to the wrong entity, a denial that looks like a credentialing issue, and a write-off that never needed to happen.

The stakes are real. For a mid-size outpatient behavioral health practice billing 1,500 to 2,000 Medicaid encounters per month, misrouting claims due to carve-out confusion typically costs between $18,000 and $34,000 in net monthly collections, based on the denial and write-off patterns we track internally. This post breaks down what the carve-out landscape actually looks like in 2026, which states are most problematic, and what your billing team needs to do differently starting this week.

Carved In vs. Carved Out: What Actually Changes at the Claim Level

When a state carves behavioral health into the MCO, the enrollee’s physical health plan also manages mental health and SUD benefits. The MCO receives a capitated rate that includes behavioral health, and your claims go directly to that MCO using their payer ID, their fee schedule, and their prior authorization portal.

When behavioral health is carved out, a separate specialty behavioral health organization (SBHO) or behavioral health organization (BHO) manages those benefits under a separate contract with the state. Examples include Beacon Health Options in several markets, Magellan in others, and state-operated entities like California’s Medi-Cal managed specialty mental health plans run by county programs.

At the claim level, the practical differences include:

Payer ID: A carved-out claim submitted to the MCO’s payer ID will reject or deny as non-covered. The claim must go to the carve-out entity’s separate EDI endpoint.
Fee schedule variance: Carved-out BH fee schedules frequently differ from the MCO’s BH rates by 15% to 40% on the same CPT code. We see this most dramatically on CPT 90837 (individual therapy, 60 minutes), where the MCO rate and the SBHO rate for the same enrollee category in the same state can differ by $30 to $55 per unit.
Prior authorization requirements: Carve-out entities almost universally require separate prior authorization for higher-level-of-care services, including PHP (CPT H0035) and IOP (CPT H0015), even when the MCO would not have required it.
Modifier and POS requirements: Telehealth billing for carved-out Medicaid plans frequently still requires the GT modifier in addition to POS 02 or POS 10, even in states where commercial MCOs have moved away from GT.

Which States Have the Most Complex Carve-Out Structures in 2026

The states where we see the highest denial rates specifically tied to carve-out misidentification are California, Texas, New York, Pennsylvania, and Ohio. That is not a coincidence. Each of these states runs a hybrid or multi-tiered Medicaid managed care structure where the carve-in or carve-out status can differ by county, by MCO, by eligibility category, or by benefit type within the same patient.

In California, Medi-Cal’s transition to CalAIM has moved most behavioral health into county-operated mental health plans (MHPs) for specialty mental health services, while Drug Medi-Cal Organized Delivery System (DMC-ODS) carves out SUD services separately in counties that have implemented the waiver. A single California Medi-Cal enrollee may have their outpatient therapy covered by the county MHP, their medication-assisted treatment covered by DMC-ODS, and any co-occurring physical health need covered by their Medi-Cal managed care plan. Three different billing pathways for one patient.

In Texas, STAR Health and STAR+PLUS both use managed care, but behavioral health carve-out status varies by service type and by which MCO (Molina, UnitedHealthcare Community Plan, Superior HealthPlan, etc.) the enrollee is assigned to. Texas Medicaid also requires NPI-level enrollment with each MCO separately, meaning a provider credentialed with the state Medicaid program is not automatically in-network with any MCO.

The CPT Codes Most Affected by Carve-Out Routing Errors

Based on the denial data we review across our client base, the CPT codes generating the highest dollar volume of carve-out-related denials are:

CPT 90837 (psychotherapy, 60 min): Highest volume outpatient therapy code; denial rate spikes when submitted to wrong entity.
CPT 90847 (family psychotherapy with patient): Often covered under the carve-out but excluded from the MCO’s BH benefit in some state contracts.
CPT 99213 / 99214 with modifier 25: When psychiatrists bill E/M plus psychotherapy add-on codes (90833, 90836), carve-out plans often require the E/M to go to the physical health MCO and the therapy add-on to go to the carve-out entity. Splitting a single encounter across two payers is a workflow most billing teams are not set up to handle.
H codes for structured programs: H0015 (IOP), H0035 (PHP), H2019 (therapeutic behavioral services) are almost exclusively covered under carve-out plans, not the MCO. Submitting H codes to a carved-in MCO typically results in a non-covered denial that gets written off instead of rerouted.
CPT 96160 / 96161 (health risk assessments): Covered under behavioral health benefit in some states, physical health in others. Carve-out status determines which payer processes the claim.

Prior Authorization and Medical Necessity Differences You Cannot Ignore

One of the highest-impact differences between carved-in and carved-out Medicaid plans is how prior authorization and medical necessity criteria are applied. Carved-out SBHOs frequently use their own proprietary medical necessity criteria rather than the state’s base Medicaid criteria. This is directly relevant to MHPAEA compliance, because a carve-out entity applying more restrictive criteria than what the state allows for equivalent medical/surgical benefits is a parity violation. We have written about how practices can leverage MHPAEA parity appeals to recover denied claims at Revenant Care Group’s MHPAEA parity appeals resource, and the mechanics described there apply directly to carved-out Medicaid managed care denials.

For SUD-focused practices specifically, the carve-out structure intersects with drug screening billing in ways that create additional revenue leakage. If your practice is billing G0480 through G0483 for definitive drug testing, the payer responsible for those codes under a carved-out structure is almost always the physical health MCO, not the behavioral health carve-out, since lab services typically remain with the medical benefit. Billing those codes to the SBHO will produce a consistent non-covered denial. We cover the correct coding framework for definitive drug screens at our G0480-G0483 drug screen coding guide.

Operational Fixes Your Billing Team Can Implement Now

The carve-out problem is fundamentally an eligibility verification problem at its root. These are the process changes we recommend to our clients immediately:

Build a state-specific carve-out reference grid that maps each Medicaid MCO in your operating states to its behavioral health coverage structure, the carve-out entity name if applicable, the payer ID for BH claims, and the phone number for BH prior authorization. Update this quarterly. MCO contracts change at state fiscal year transitions.
Verify benefit segmentation at intake for every Medicaid patient, not just MCO membership. Your eligibility verification workflow needs to confirm which entity covers behavioral health specifically, not just confirm active Medicaid coverage.
Audit your existing denial queue for non-covered denials on BH codes from Medicaid MCOs. A significant portion of those denials, in our experience 30% to 45% of them in states with carve-out structures, are actually misrouting errors that are correctable by resubmitting to the carve-out payer with timely filing still intact.
For E/M plus psychotherapy encounters, determine in advance which payer gets which code. Document the split billing protocol for your billing team in writing so it is applied consistently at charge entry.
Confirm modifier requirements separately for each carve-out entity for telehealth. POS 02 vs. POS 10, GT modifier required or not, and synchronous vs. asynchronous coverage rules all vary by carve-out payer even within the same state.

What Recovery Looks Like When You Fix This

For practices we have worked with that had significant carve-out misrouting in their denial inventory, the average recovery from reworking 90 to 120 days of denials runs between $22,000 and $65,000 in net collections, depending on practice size and state. A solo psychiatrist practice in a heavily carved-out state like Pennsylvania might recover $8,000 to $15,000 from a focused rework project. A 10-clinician outpatient group in California working through county MHP vs. MCO misrouting can see recoveries above $50,000 from a single audit cycle. These are not theoretical numbers. They are consistent with what we see in the denial data we work through on behalf of our clients.

The key is acting on denials before timely filing limits close the window. Most Medicaid MCOs and SBHOs allow 90 to 180 days from date of service for initial claim submission, but corrected claim timely filing windows vary. Do not let a misrouting error become a permanent write-off.

Start With a Free 30-Day Denial Audit

If your practice operates in a state with Medicaid managed care and you are not certain whether your billing team has correctly mapped your patients’ behavioral health carve-out status, that uncertainty is costing you money right now. At Revenant Care Group, we offer a free 30-day denial audit specifically designed to identify carve-out misrouting, parity violations, and coding gaps in your existing claim inventory. Schedule a time with our team directly at our scheduling page and we will show you exactly where the revenue is going and what it takes to bring it back.