A lumbar MRI looks like an easy claim. One scan, one code, one payment. Then the denial arrives and the reason reads "medical necessity not established". The practice already paid for the technologist, the scanner time and the radiologist's read. Nobody paid the practice.
This guide looks top to bottom at CPT code 72148: what it describes, how to bill it, what Medicare pays and where claims fall apart. A2Z Billings has 150+ years of combined billing experience on staff, and here is what that experience says about getting a lumbar MRI paid the first time.
What 72148 describes
The CPT code for an MRI of the lumbar spinal canal and contents, without contrast, is 72148. No gadolinium is included. It’s a scan of the lower back and shows the vertebrae, the discs and the nerves that run through them. Doctors prescribe it for disc herniation, spinal stenosis, radiculopathy, early osteomyelitis and other things.
How it differs from 72149 and 72158
The lumbar MRI family consists of three codes. 72148 is non-contrast. 72149 is contrast only. 72158 is performed without contrast, followed by 'with contrast' in the same session. The code reflects what happened to the scanner, not the order mentioned. Contrast came in partway through the exam; 72148 is the wrong code.
Global, professional and technical billing
72148 splits into two parts. The radiologist who only reads the images bills the service with modifier 26. The facility that owns the scanner and employs the technologist bills modifier TC. A group that does both bills the code with no modifier.
One rule causes confusion. The same provider cannot put both 26 and TC on the same service line, and the claim will be rejected if that happens. Noridian's review page adds a related point: the technical component cannot happen without the professional component, and Medicare usually pays for only one professional read per scan.
What Medicare pays for 72148
The physician fee schedule Medicare payment is $191.72 nationwide. It's 5.74 RVUs (work 1.44, practice expense 4.20, malpractice 0.10) times $33,400.90. The professional read is $68.47; the technical is $123.25.
Your actual check moves with the locality adjustment. A practice in Manhattan and one in rural Kansas are paid differently for the same scan.
What the neighbouring codes pay
Nationally, 72149 pays $217.84 and 72158 pays $297.55. The gap matters in both directions. Bill 72158 when no contrast was given and you invite a recoupment. Bill 72148 for a two-phase study, and you forfeit $105.83.
What the patient owes
Original Medicare pays 80 percent of the allowed amount once the Part B deductible is met. On $191.72, Medicare pays $153.38 and the patient owes $38.34. Collect that coinsurance. A scan that gets paid by Medicare but never collected from the patient is still a leak.
Office, imaging center and hospital settings
Where the scan takes place determines who gets paid and how much. The technical side is done by going through the fee schedule in a physician’s office or a free-standing imaging centre. In a hospital outpatient department, the hospital's technical fee is subject to a separate outpatient payment system, but the radiologist still bills the professional read to the fee schedule. An incorrect place-of-service code will cause automatic adjustments, so verify it prior to releasing the claim.
Commercial payer reimbursement
Commercial plans pay a multiple of Medicare. Pabau's code guide puts the range at 125% to 300% of the Medicare rate, depending on the contract. Against a $191.72 benchmark, that works out to roughly $240 to $575 per scan.
Your contract decides where you land. Honestly, many practitioners haven't read their imaging rate schedule in years. Start there.
Medical necessity under Medicare
Medicare’s position is simple enough to declare. Don’t get spinal imaging in the first month of symptoms unless the history and exam show a red flag, which is a sign of an emergent condition such as cancer, infection, fracture, or cauda equina syndrome. If there are no red flags, the scan may be appropriate at one month. Medicare also requires that the result be included in a medical decision.
This is where local coverage determinations come in. One example is L34220, published by Noridian for its western jurisdictions. Your contractor may have a different policy number. Read the policy relevant to your claims.
Why Medicare reviewers deny 72148
Noridian's Jurisdiction E medical review team ran a targeted probe-and-educate review of 72148. The three top denial reasons are failure to return records, incomplete or insufficient documentation, and documentation that did not support medical necessity under the coverage policy.
None of the three is a coding error. Records requests go unanswered, notes arrive thin, and the order never says why the scan was needed. You can fix all of it before the claim goes out.
Documentation that gets paid
Make the chart before you say no. Not going with the pick. You need the treating clinician's signed order and a visit note that lists the start and length of the symptoms for a proper file. It lists the dates of the exam, any red flags that were found, and conservative treatments like home exercises, physical therapy, and painkillers.
It also describes what will happen next. Planned surgery, an injection, and a referral are all mentioned. If the note does not clearly state the purpose of the scan, the reviewer may assume it is not for the stated reason.
Prior authorization with commercial plans
Medicare generally doesn't ask for authorization on this scan. Many commercial plans do. According to its published preauthorization list, Humana requires it for lumbar MRI on commercial plans, and plans often send requests through radiology benefit managers such as eviCore or Carelon.
Blue Cross Blue Shield of South Carolina's policy asks for at least six weeks of failed conservative treatment within the last six months. Closed therapy offices, patient inconvenience, and unexplained noncompliance do not count as valid reasons for being unable to complete treatment. Look, if the chart doesn't explain the gap, the plan won't either. Some plans also want a peer-to-peer call when the paperwork leaves doubt.
Modifiers beyond 26 and TC
26 or TC is sufficient for most claims. A few other people come. Modifiers 59 and XS are used to show that a service was performed separately when two studies were performed on the same date. CMS prefers modifier X over modifier 59, when appropriate, to be more specific. Documentation of same-day repeats as unusual circumstances is required for both 76 – repeat scan by the same physician and 77 – repeat scan by another physician.
For a Medicare patient who may not meet the coverage policy, GA shows a signed ABN is on file. GZ indicates that you anticipated the denial and do not have an ABN.
Same-day studies and bundling
72148 and 72149 on one claim for the same lumbar spine collide under an NCCI edit, and no modifier fixes that. 72158 already includes the non-contrast lumbar study, so billing both codes results in double counting.
Thoracic MRI (72146) and cervical MRI (72141) are billed separately because they are different anatomies. Numbers will drop. Repeat studies in the same imaging family on the same day cost Medicare less for technical services. Payers ask why you bill both 72148 and 72110, even though AAPC forum coders say there is no NCCI edit between them.
Diagnosis coding that supports the scan
The medical necessity justification is the ICD-10 code. M54.50: Low back pain, unspecified. This option is usually the weakest choice, since it provides you no information on the cause. Match the scan to the diagnosis the provider documented. M54.16 lumbar radiculopathy, M51.16 lumbar disc disorder with radiculopathy, M48.061 or M48.062 lumbar stenosis without or with neurogenic claudication G83.4 cauda equina syndrome
Code what the chart supports and nothing more.
Filing deadlines and appeals
Medicare allows 12 months from the date of service to file a claim. Commercial windows are shorter and vary by contract, so pull the number for each payer you bill. If your claim is denied, appeal it with the exact records the reviewer said were missing and send them in within the response window. The Noridian denial list is topped by failure to return records, meaning a late reply loses claims you could have won.
Mistakes that cost practices the most
Four errors repeat themselves. The first month of back pain has a scan billed, and no red flags are documented. The order is not clinically justifiable and has a fuzzy diagnosis. Modifiers 26 and TC are reversed or doubled. A records request is ignored until the deadline has passed. Each one is cheap to prevent and expensive to appeal, and the last one has a clear price: Noridian ranked unreturned records as the number one denial reason for this code.
A pre-release check for every 72148 claim
Before a claim leaves, confirm five things. Contrast status matches the code. The modifier matches who did the work. The ordering clinician's NPI is on the claim. The diagnosis matches the documented reason for the scan. Any authorization number is attached. That check takes a few minutes per claim, and a resubmission takes weeks.
Frequently asked questions
What does 72148 stand for?
It stands for MRI of the lumbar spinal canal and contents without contrast material. If contrast is given at any point during the exam, report 72149 or 72158 instead.
How much does Medicare pay for 72148?
The total national amount for the physician fee schedule is $191.72, comprising $68.47 for the professional component and $123.25 for the technical component. Locality corrections shift the figure up or down.
Can I bill 72148 and 72149 together?
No, sir. An NCCI edit that a modifier cannot override occurs when billing for the same lumbar spine on one claim. Bill 72158 if the patient had non-contrast and contrast sequences.
Does 72148 need prior authorization?
Original Medicare generally doesn't require it. Many commercial plans do, including Humana's commercial plans per its published list. Check each payer's current policy before scheduling the scan.
When do I use modifier 26 or TC?
Use 26 for just reading the images. Use TC only when the equipment and the technologist are provided. Bill without a modifier when you do both. 26 and TC shouldn't be on the same line.
What is 72148 used for in the diagnoses?
3.4 G8 or specific codes are preferred: M54.16, M51.16, M48.061, M48.062, M54.50 Low back pain, unspecified Rarely needed, especially in the first month of symptoms.
The statute of limitations on a 72148 claim is 2 years. 2 years ago?
Medicare allows 12 months from the date of service. Commercial payment due dates vary by contract, so always check the timely filing limit for each payer.
Can I bill 72148 with a cervical or thoracic MRI on the same day?
Yes, you can bill both if they are different areas. The chart shows all of them. Before you add a modifier of 59 or XS, check the payer edits. The payment for the next study will be technically lower.
Is there Medicare coverage for a lumbar MRI during the first month of back pain?
Usually not, unless the history and exam document a red flag such as suspected cancer, infection, fracture or cauda equina syndrome. Without one, Medicare says symptoms should last a month first.
What is the difference between 72148 and 72158?
72148 covers the lumbar scan without contrast. 72158 covers a study run without contrast and then repeated with contrast in the same session. It pays $297.55 nationally against $191.72 for 72148.
Get paid for every lumbar MRI you perform
Imaging claims fail on paperwork, not on the scan. That is fixable, and A2Z Billings fixes it for practices every day. We have a 98% first-pass clean claims rate, with every claim coded and double-checked by speciality before it leaves us. You have a dedicated coder who knows your payer mix, your denial patterns and your radiology workflow.
There is no long-term contract. Plans start at 3% of monthly collections. We only win if you do. Schedule your free audit and consultation, and we’ll show you where your imaging revenue is leaking and how to fix it.