CPT Code 72148: A 2026 Guide to Billing MRI Lumbar Spine Without Contrast

What is CPT code 72148 and how is it billed?

CPT code 72148 reports a magnetic resonance imaging study of the lumbar spine performed without contrast material. It is used to evaluate disc disease, spinal stenosis, radiculopathy, and similar lower-spine conditions when no intravenous contrast is given. Most payers require prior authorization for lumbar MRI and many also require a documented trial of conservative care before approving the study.

• The three lumbar MRI variants: 72148 is without contrast, 72149 is with contrast, and 72158 is without contrast followed by with contrast; bill the code that matches the report.
• Prior authorization and conservative care: Most payers require prior authorization plus a documented conservative trial (often four to six weeks of physical therapy or medication) before approving 72148.
• Modifiers for 72148: Use modifier 26 for the professional interpretation only, TC for the technical component only, and no modifier when one entity bills the global service.

What Does CPT 72148 Cover?

CPT 72148 covers a magnetic resonance imaging study of the lumbar spine performed without contrast material. It captures the imaging used to evaluate disc disease, spinal stenosis, radiculopathy, compression fractures, and similar lower-spine conditions when no intravenous contrast is administered during the study.

The code is defined in the American Medical Association’s CPT code set and sits inside the family of spine MRI codes that includes cervical, thoracic, and lumbar variants, each with its own contrast options. 72148 is the without-contrast variant for the lumbar region.

In clinical practice, 72148 is the standard MRI for evaluating chronic or persistent low back pain with radicular symptoms, suspected disc herniation, lumbar spinal stenosis, and pre-surgical planning when contrast is not required. The American College of Radiology Appropriateness Criteria for Low Back Pain rate MRI lumbar spine without contrast as usually appropriate for patients with persistent or progressive symptoms after six weeks of optimal medical management who are candidates for surgery or intervention.

The without-contrast designation is part of the code identity, not a detail to skip. If contrast is administered, a different code applies. Billing the wrong contrast variant is one of the most common radiology denials, and the fix starts with reading the radiology report, not the order.

How Does 72148 Differ From 72149 and 72158?

The three lumbar MRI codes differ only by contrast use. 72148 is without contrast, 72149 is with contrast, and 72158 is without contrast followed by with contrast. The radiology report documents whether contrast was administered, and the code billed must match the report, not the referring order.

The choice between codes is clinical, driven by what the ordering physician is trying to answer. Non-contrast MRI (72148) is standard for degenerative disc disease, spinal stenosis, and radiculopathy workups. Contrast becomes relevant when the question involves infection, tumor, inflammatory disease, or post-surgical evaluation, where enhancement patterns matter.

The pattern repeats across radiology. Contrast variants exist for CT and MRI studies throughout the body, and the coding rule is the same: bill what the report documents. For a parallel example in cross-sectional CT imaging, see CT abdomen and pelvis without contrast.

Does 72148 Require Prior Authorization?

Most payers require prior authorization for lumbar MRI, including 72148. Medicare Advantage plans, commercial payers, and many Medicaid plans use radiology benefit managers that apply the American College of Radiology Appropriateness Criteria and payer-specific medical necessity rules before approving the study. Traditional Medicare does not require pre-authorization for most outpatient MRI studies.

The prior authorization process typically asks for the clinical indication, the ICD-10 diagnosis, prior imaging results, documentation of conservative care attempted, and the referring physician’s clinical rationale. Radiology benefit managers score the request against appropriateness criteria and return an approval, an approval with limits, a denial, or a request for peer-to-peer review with the ordering clinician.

In our experience matching providers with billing partners across imaging centers and radiology practices, missing or incomplete prior authorization is the single most common reason a lumbar MRI claim is denied. The coding itself is often clean; the study just never had the authorization it needed. That is not a coding fix, it is a workflow fix, and it has to happen before the patient is on the scanner.

For a broader look at appropriateness standards that inform payer criteria, see our overview of guidelines from the American College of Radiology.

What Is the Conservative-Care Rule for Lumbar MRI?

Many payers require documented conservative care before approving a lumbar MRI for non-emergent low back pain. The standard benchmark is four to six weeks of conservative measures such as physical therapy, medication, or activity modification, aligned with the ACR Appropriateness Criteria threshold of six weeks of optimal medical management before imaging.

Red-flag findings bypass the conservative-care requirement. Suspected cauda equina syndrome, significant or progressive neurologic deficit, suspected malignancy, suspected infection, and significant trauma all justify immediate imaging. The prior authorization request should identify any red flags present so the reviewer routes the case correctly.

The clinical note supporting a 72148 request should include:

• Document the conservative trial duration (typically four to six weeks) and each intervention attempted.
• Record symptom progression, noting whether pain, radicular symptoms, or functional limitations improved.
• Note any red-flag findings that bypass the conservative-care threshold (significant weakness, bowel or bladder dysfunction, suspected malignancy, trauma).
• Include the referring physician’s clinical rationale and the specific question the MRI is expected to answer.
• Attach current physical exam findings, prior imaging results, and any surgical or interventional planning notes.

Providers often come to us after a run of lumbar MRI denials where the coding was correct and the study was clinically indicated, but the conservative-care documentation was thin. A short peer-to-peer call can rescue an individual claim, but the durable fix is a referral template that captures the six required elements above at the point of order entry.

What Modifiers Should Be Used With 72148?

72148 splits into professional and technical components. Bill modifier 26 for the professional interpretation only when the radiologist bills separately from the imaging facility. Bill modifier TC for the technical component only when the facility owns the scanner and equipment. Bill the global service with no modifier when one entity provides both.

The split is common in outpatient imaging. An independent radiology group reading studies for a hospital or imaging center bills the professional component with modifier 26, and the facility bills the technical component with modifier TC. When a fully integrated imaging center employs the radiologist and owns the scanner, the same NPI bills the global service.

Laterality modifiers do not apply to 72148. The lumbar spine is a midline structure, so left and right (LT, RT) modifiers are not appropriate. The component modifier is the one that matters for this code.

Common modifier errors we see across the billing companies we vet include appending modifier 26 when the same entity also owns the scanner, omitting the TC modifier on a technical-only claim, and adding a laterality modifier out of habit from extremity imaging. Each is a fixable claim scrub error, but each costs a resubmission cycle when it slips through.

What Diagnosis Codes Support 72148?

The most common ICD-10 codes supporting 72148 include M54.50 for low back pain unspecified, M54.51 for vertebrogenic low back pain, M54.59 for other low back pain, M54.16 for lumbar radiculopathy, M54.17 for lumbosacral radiculopathy, M51.36 for lumbar disc degeneration, and M48.06 for spinal stenosis of the lumbar region. The claim diagnosis must match both the clinical documentation and the payer’s medical necessity list.

Specificity matters more than it used to. The ICD-10-CM FY2026 edition (effective October 1, 2025 through September 30, 2026) keeps M54.50, M54.51, and M54.59 as the three billable low back pain codes, and payers scrutinize claims that default to the unspecified M54.50 when the clinical documentation supports a more specific choice. Vertebrogenic pain documented on exam or prior imaging should code to M54.51, not M54.50.

Radiculopathy codes matter for MRI approvals because they signal the neurologic involvement that shifts appropriateness criteria toward imaging. When the note supports lumbar radiculopathy, code M54.16 or M54.17 rather than the generic low back pain code. Payers also require Excludes1 discipline. M54.50 cannot be coded alongside S39.012 (low back strain), M51.2 (lumbago with disc displacement), or M54.4 (lumbago with sciatica) on the same claim.

One question we hear constantly from radiology practice managers is why a claim with a valid code and a scanned patient still gets denied for medical necessity. The answer is almost always that the referring provider’s note carries a generic M54.50, but the payer’s criteria expected a specificity marker (radiculopathy, stenosis, or documented conservative trial) that the coding never surfaced.

How Much Does Medicare Pay for 72148 in 2026?

Medicare publishes an annual allowance for 72148 in the Medicare Physician Fee Schedule, split between the professional and technical components and adjusted by locality. The exact 2026 amount varies by MAC region, and the total global allowance is different from the professional-only (modifier 26) or technical-only (modifier TC) allowances. Refer to the current CMS 2026 fee schedule for the specific numbers that apply to your locality.

Commercial payer contracts often reference the Medicare rate as a benchmark but apply their own multiplier, which can move actual reimbursement above or below the Medicare number. When a practice bills the professional component only, the payment maps to the physician’s contract and locality; when the same practice also owns the scanner, the technical piece flows to the facility side of the contract at a different rate.

Because the numbers change annually and vary by locality, payer, and component, we do not publish a fixed dollar figure for 72148. The right operational answer is to run the current fee schedule against your top payer mix at the start of each year and refresh it after the January MPFS update, rather than working from a stale estimate.

Why Do 72148 Claims Get Denied?

The most common 72148 denials trace back to five patterns: missing or expired prior authorization, no documented conservative care for low back pain, the wrong contrast variant billed, a missing or incorrect component modifier, and a diagnosis that does not support medical necessity. Every pattern is preventable before the scan is performed.

• Missing prior authorization, where the study was performed before the payer approval was in hand or after it expired.
• Insufficient conservative care documentation, where a lumbar MRI was ordered for low back pain without evidence of the required four-to-six-week trial.
• Wrong contrast variant, where 72148 was billed but the report documented contrast, or 72149 or 72158 was billed for a non-contrast study.
• Component modifier errors, where modifier 26 or TC is missing, doubled, or applied by the wrong entity for the billing structure in place.
• Diagnosis mismatch, where the ICD-10 code on the claim does not support medical necessity under the payer’s coverage policy.

Across the billing companies we vet, a recurring pattern separates radiology practices that keep 72148 clean from those that fight denials month after month. The clean ones build the authorization check, the conservative-care documentation audit, and the contrast-variant scrub into a pre-scan workflow. The ones that struggle treat the front-end as the referring provider’s problem, then absorb the denials on the back end.

For a parallel example of how contrast variants and component modifiers behave in cross-sectional imaging, see our guide to CT head without contrast (CPT 70450).

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