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- X12 CARC 50: these are non-covered services because this is not deemed a medical necessity by the payer.
- , makes the agency the final arbiter, and says that for behavior analysis services the determination may be made by a licensed physician or a doctoral-level board-certified behavior analyst.
- 2). For recipients under 21, services beyond the policy may be approved if medically necessary under EPSDT.
What CO-50 means
X12 defines CARC 50 as "These are non-covered services because this is not deemed a 'medical necessity' by the payer." With group code CO, the amount is a contractual write-off unless the decision is overturned. Unlike CO-16 or CO-197, you usually cannot fix CO-50 by correcting a field. You respond with clinical documentation through the payer's reconsideration, peer-to-peer or appeal process.
Watch out. Do not resend the same claim. If anything was wrong, submit a corrected claim so the payer does not deny it as a duplicate.
How Florida defines medical necessity for ABA
Florida's Medicaid integrity statute defines medically necessary goods or services as those necessary to palliate the effects of a terminal condition, or to prevent, diagnose, correct, cure, alleviate, or preclude deterioration of a condition that threatens life, causes pain or suffering, or results in illness or infirmity, provided in accordance with generally accepted standards of medical practice (section 409.913(1)(d), F.S.). For behavior analysis, the same paragraph lets the determination be made by a licensed physician or a doctoral-level board-certified behavior analyst, based on information available when the service is requested.
The behavior analysis coverage policy points to Rule 59G-1.010 for the definition and sets ABA-specific conditions. Services are for recipients under 21 with behavior that impairs a major life activity (safety, communication, self-stimulating, self-care and others listed in section 2.2). A referral must come from an independent physician or qualified practitioner and include a physician's order and a comprehensive diagnostic evaluation (CDE).
What usually triggers CO-50 in ABA
- Hours not tied to the plan. Florida covers up to 40 hours per week of intervention as indicated in the recipient's prior-authorized behavior plan (section 4.2.2). Units beyond what the plan justifies invite a necessity denial.
- Weak progress evidence at reauthorization. Section 6.2.3 requires data on every targeted behavior, each with its own data table and graph, plus a narrative and a justification for the intensity requested. If progress stalls, the provider must explain why and what treatment changes were made.
- Services that look like non-covered support. Section 5.2 excludes recipient supervision, 1:1 aide, companion, chaperone or shadow services, caregiver or childcare services, and travel time.
- Duplicate services. Services that unnecessarily duplicate another provider's service are not covered (section 5.1), and services delivered simultaneously by more than one BA provider need medical necessity, prior authorization and inclusion in the approved plan.
How to respond
- Confirm the denial reason and any policy reference. X12's usage note says to check the 835 Healthcare Policy Identification segment if the payer sent one.
- Gather the CDE, physician order, current assessment, behavior plan with measurable goals, progress graphs, and the session notes for the denied dates.
- Ask for a peer-to-peer review if the plan offers it. Sunshine Health, for example, lists a BA peer-to-peer request form among its provider resources.
- Write the appeal around the plan's criteria: functional impairment, measurable targets, baseline, progress, and why the requested intensity is needed now.
Prevent it in the notes
Medical necessity is argued at authorization, but it is proven session by session. Florida's session note requirements (section 6.2.4) ask for the maladaptive behaviors observed, the replacement skills targeted, the recipient's response, and any protocol changes. Notes that read the same every day, or never mention the behavior plan's targets, make a CO-50 easier for a reviewer to uphold. A pre-claim note check that flags notes missing targets, behaviors or response gives your clinicians a chance to fix the record while the session is fresh.
Whatever software you use, the pattern is the same: the claim is built from the session note, so most of these problems can be caught before the claim is submitted.
Tip. Read the RARC on the same remittance line. It often names the exact field or document the payer wants.
FAQ
What does CO-50 mean?
X12 CARC 50: these are non-covered services because this is not deemed a medical necessity by the payer. Group code CO means the amount is a contractual adjustment.
Who decides medical necessity for ABA in Florida Medicaid?
Section 409.913(1)(d), F.S., makes the agency the final arbiter, and says that for behavior analysis services the determination may be made by a licensed physician or a doctoral-level board-certified behavior analyst.
How many ABA hours does Florida Medicaid cover?
Up to 40 hours per week of behavior analysis intervention as indicated in the recipient's prior-authorized behavior plan (coverage policy section 4.2.2). For recipients under 21, services beyond the policy may be approved if medically necessary under EPSDT.
Clean notes, clean claims, paid claims.
We check every ABA session note before the claim is built, and you keep the PM software you already use.
Related guides
Sources
- X12, Claim Adjustment Reason Codes
- X12, Claim Adjustment Group Codes
- Section 409.913, Florida Statutes (Oversight of the integrity of the Medicaid program)
- AHCA, Florida Medicaid Behavior Analysis Services Coverage Policy (Dec 2024), incorporated in Rule 59G-4.125, F.A.C.
- Sunshine Health, BA provider enrollment pause ends (Feb 20, 2026)
Last reviewed October 2026. This page summarizes public rules and vendor pages for education; it is not legal or billing advice. Payer contracts and plan manuals can add requirements, so confirm with the payer.