Humana MRI or CT Scan Denied? Prior Auth Appeal Guide

Diagnostic imaging — MRI, CT scan, PET scan, ultrasound — is among the most commonly prior-authorized and most commonly denied categories of medical services. If Humana denied your MRI or CT scan, you are likely dealing with a Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization denial managed through Humana's radiology benefits management program. Understanding exactly how Humana evaluates imaging requests is the foundation of an effective appeal.

Why Humana Denies MRI and CT Scan Requests

Humana partners with AIM Specialty Health (now part of Veradigm) as its radiology benefits management vendor. When your physician submits a prior authorization request for an MRI or CT scan, that request is reviewed using ACR Appropriateness Criteria — guidelines published by the American College of Radiology that rate imaging studies on a scale of 1–9 for specific clinical scenarios. Studies rated 7–9 are "Usually Appropriate"; those rated 4–6 are "May Be Appropriate"; those rated 1–3 are "Usually Not Appropriate." Common denial reasons include:

• Clinical indication not established — The prior authorization request does not adequately document the clinical indication (symptoms, duration, prior workup) that makes the imaging appropriate. Reviewers need to know not just what was ordered but why this specific patient needs it now.
• Imaging not clinically appropriate per ACR criteria — AIM/Humana determined that for the stated indication, a different imaging study or no imaging is the appropriate next step. For example, MRI for low back pain of less than 6 weeks' duration with no red flag symptoms, when ACR criteria recommend conservative treatment first.
• Prerequisite clinical steps not completed — Many imaging criteria require that certain clinical steps occur first: conservative treatment trial, plain X-rays before MRI, or specialist evaluation.
• Incorrect CPT code or missing clinical information — The PA was submitted with a code that does not match the clinical scenario, or critical clinical history was omitted.
• Alternative imaging is ACR-appropriate first-line — Humana may approve X-ray or ultrasound when ACR criteria rate those as equally appropriate initial studies for the indication.

How to Appeal a Humana Imaging Denial

Step 1: Obtain the Denial and Identify the ACR Criteria Applied

Request the written denial notice specifying which ACR Appropriateness Criteria scenario and rating AIM/Humana applied. If this is not specified, call 1-877-320-1235 and request the specific ACR topic, variant, and appropriateness rating cited in the denial. This is your precise target for rebuttal.

Step 2: Research the Applicable ACR Appropriateness Criteria

The ACR Appropriateness Criteria are freely available at acr.org/Clinical-Resources/ACR-Appropriateness-Criteria. To use them in your appeal:

1. Identify the ACR topic that matches your condition and the clinical question the imaging is meant to answer
2. Find the specific variant that most closely matches your clinical presentation
3. Confirm the ACR rating for the ordered imaging modality in that variant
4. If the ordered study is rated 7–9 (Usually Appropriate), you have strong grounds for reversal

For example: "ACR Appropriateness Criteria for Low Back Pain, Variant 5 (Radiculopathy or Radicular Pain Without Prior Treatment) rates MRI Lumbar Spine Without Contrast as 9 — Usually Appropriate. The patient presents with [specific symptoms matching this variant]."

Step 3: Have Your Physician Prepare a Targeted Appeal Letter

Your ordering physician should prepare a letter including:

1. Complete clinical history — symptoms, duration, severity, functional impact, and specific red flag findings
2. Prior workup and treatments completed (meeting any prerequisite requirements AIM cited)
3. Any urgent or red flag clinical indicators (suspected malignancy, acute neurological symptoms, vascular emergency)
4. The specific ACR Appropriateness Criteria topic, variant, and rating supporting the ordered study
5. Why alternative imaging modalities are insufficient to answer the clinical question for this patient

Step 4: Request Peer-to-Peer Review Immediately

Peer-to-peer review is consistently the most effective tool for overturning Humana imaging denials. The call allows your ordering physician to provide complete clinical context, cite the specific ACR criteria, clarify information missing from the original PA request, and advocate for urgent review if needed. Call 1-877-320-1235 to request the peer-to-peer. Schedule it promptly — reviewers typically need to be reached within a few business days of the denial.

Step 5: Invoke Expedited Review for Urgent Clinical Situations

If the imaging is needed urgently — to evaluate possible cancer, acute neurological symptoms, vascular emergency, or other time-sensitive conditions — you are entitled to an expedited prior authorization decision within 72 hours under Medicare Advantage rules. Call 1-877-320-1235 and ask specifically for expedited review, with your physician documenting in writing why delay poses a health risk. Do not wait the standard review period for time-sensitive diagnoses.

Step 6: File the Formal Internal Appeal and Escalate

Submit your formal internal appeal within 60 days (Medicare Advantage) or 180 days (commercial plans) of the denial. Cite 45 C.F.R. § 147.136 for ACA plans or 29 U.S.C. § 1133 for ERISA plans. If Humana upholds the denial, request External Independent Review: Complete Guide" class="auto-link">external review — an IRO with radiology expertise will conduct an independent review binding on Humana.

What to Include in Your Humana Imaging Appeal

• Denial notice with the specific ACR scenario and rating AIM/Humana cited
• ACR Appropriateness Criteria printout showing the topic, variant, and rating for your clinical situation — highlighting the "Usually Appropriate" designation if applicable
• Physician letter with complete clinical history, red flag symptoms, prior workup, and ACR citation
• Documentation of prerequisite steps completed — conservative treatment, prior imaging, specialist evaluation — that AIM cited as missing
• Legal citations including 45 C.F.R. § 147.136 (ACA internal appeal), 29 U.S.C. § 1133 (ERISA), and 42 C.F.R. § 422.101 for Medicare Advantage members

Fight Back With ClaimBack

A Humana MRI or CT scan denial is most effectively overturned by citing the specific ACR Appropriateness Criteria that rates your imaging as Usually Appropriate and providing the clinical context AIM's initial review lacked. ClaimBack generates a professional appeal letter in 3 minutes.

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Related Reading

• How to Write an Insurance Appeal Letter
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• Internal vs External Insurance Appeal