In this guide12 sections
- Key takeaways
- What an MRI can and can’t prove
- How long MRI approval takes
- What to do if workers’ comp denies your MRI
- How MRI findings affect causation and your rating
- Degenerative findings and apportionment
- How a rating turns into money
- L4-L5 and L5-S1 disc injuries
- Future medical care and how you settle
- Protecting your claim step by step
- Frequently asked questions
- Talk to a California workers’ comp lawyer
An MRI does not set the value of your workers’ comp case by itself, but it often decides how strong your medical evidence is: whether the injury is accepted, what treatment gets approved, and how the doctor rates your permanent disability. For back, neck, shoulder and knee injuries, the MRI is usually the clearest picture of what happened inside your body. That is why delays, denials and “degenerative” findings matter.
Key takeaways
- An MRI is evidence, not a price tag. It carries the most weight when it matches your symptoms, the doctor’s exam and how you were hurt.
- Utilization review must decide a routine MRI request within 5 business days, and never more than 14 days from the doctor’s recommendation, or within 72 hours if urgent (Labor Code §4610).
- If utilization review denies the MRI, request Independent Medical Review within 30 days. The reviewer decides on the records and does not examine you.
- “Degenerative” findings can lead to apportionment under Labor Code §§4663 and 4664, which can reduce the permanent disability the insurer pays, but the doctor must explain it.
- Permanent disability is paid at $160 to $290 a week for injuries since 2014, for a number of weeks set by your final rating.
What an MRI can and can’t prove
X-rays mainly show bone. An MRI shows soft tissue: spinal discs, nerve roots, ligaments, tendons, cartilage and the menisci of the knee. That makes it the standard test for herniated or bulging discs, nerve root compression that causes sciatica or radiating arm pain, rotator cuff and labral tears, and meniscus and ligament tears.
An MRI shows structure, not pain. On its own, it cannot prove that your job caused the condition or measure how much the injury limits you. Many adults have some disc bulging or wear on an MRI without symptoms, so the insurance company may argue that what the scan shows is old.
What makes an MRI powerful is how well it matches the rest of your evidence: how the injury happened, your symptoms, and what your doctor finds on examination. A doctor who ties those together is what moves a case.
How long MRI approval takes
Your primary treating physician asks for an MRI by sending a Request for Authorization (RFA) to the claims administrator. The request then goes through utilization review (UR), where a reviewer checks it against California’s treatment guidelines.
| Step | Deadline | Source |
|---|---|---|
| Routine UR decision | Within 5 normal business days of receiving the RFA and needed information, and never more than 14 days from the doctor’s recommendation | Labor Code §4610(i)(1) |
| Urgent request | Within 72 hours of receiving the needed information | Labor Code §4610(i)(3) |
| Notice of a denial or modification | To your doctor no later than 24 hours after the decision; in writing to you within 2 normal business days | Labor Code §4610(i)(4) |
| Request for Independent Medical Review | Within 30 days after the UR decision is served on you | Labor Code §4610.5(h) |
| IMR decision | Within 30 days of receiving the request and records; 3 days if expedited | Labor Code §4610.6(d) |
The total wait also depends on how fast the RFA is sent and the scan is scheduled. Ask your doctor’s office when the RFA went out, and keep every letter you receive.
If your claim hasn’t been accepted or denied yet, the employer still must authorize treatment within one working day after you file the claim form, up to $10,000, until it decides the claim (Labor Code §5402(c)). That can include diagnostic testing.
What to do if workers’ comp denies your MRI
A UR denial isn’t the final word. The next step is Independent Medical Review (IMR), run by the Division of Workers’ Compensation. The denial letter should explain how to request it, and you must file within 30 days after the UR decision is served on you.
- It is a paper review. The DWC says the reviewer does not physically examine you, so the records must clearly explain why the MRI is needed.
- It is fast and binding. The decision binds both sides and can be appealed to the Workers’ Compensation Appeals Board only on narrow grounds, within 30 days.
- It isn’t a hearing. Medical-necessity disputes over a UR denial go to IMR, not to a judge.
Your doctor can also submit a new RFA with better documentation, such as worsening symptoms, failed physical therapy or new neurological findings. If the insurer refuses the scan because it disputes your claim itself rather than the medical need, that dispute generally goes to a workers’ comp judge instead.
How MRI findings affect causation and your rating
Causation. Your injury must arise out of and occur in the course of employment. An MRI showing an acute finding in the body part you hurt, consistent with how you were injured, supports that link. If you had an earlier condition, work that aggravates it can still be a compensable injury.
Permanent disability rating. Once you reach maximum medical improvement, your treating doctor, or a QME or AME if there is a dispute, rates your impairment under the AMA Guides, Fifth Edition. For injuries on or after January 1, 2013, the whole person impairment is multiplied by 1.4 and then adjusted for occupation and age (Labor Code §4660.1).
The MRI feeds the rating but doesn’t replace the exam. For spine injuries, the doctor looks at nerve root signs, loss of motion and any surgery. Imaging that confirms those findings can support a higher impairment category; a herniation with no matching symptoms may add little. The reverse is also true: real, documented symptoms count even when the MRI is unremarkable.
Degenerative findings and apportionment
Radiology reports often use words like “degenerative disc disease,” “desiccation” or “age-related changes.” Insurers read those words closely because of apportionment.
Under Labor Code §4663, apportionment is based on causation: the rating doctor must estimate what percentage of the permanent disability was caused by the work injury and what percentage by other factors. Under §4664, the employer is liable only for the percentage directly caused by the work injury, and a prior permanent disability award is conclusively presumed to still exist.
A degenerative MRI can lower the part of your rating the insurer pays, but the doctor must explain how and why the degeneration, rather than the work injury, caused part of your disability. A conclusion that simply points to “degeneration” on a scan can be challenged. Apportionment applies to permanent disability; it generally doesn’t reduce your right to medical treatment for the work injury.
Hypothetical example: Luis, a warehouse worker, has an MRI showing a new L5-S1 herniation and mild degeneration at other levels. The QME apportions 20% of his permanent disability to pre-existing degeneration. A 20% rating before apportionment would drop to 16%.
How a rating turns into money
Permanent disability is paid in weeks. The final rating sets the number of weeks under Labor Code §4658, and your earnings set the weekly rate: two-thirds of average weekly earnings, but for injuries on or after January 1, 2014, never less than $160 or more than $290 a week for ratings under 100% (Labor Code §4453(b)).
| Final PD rating | Weeks of PD | Total at $160/week | Total at $290/week |
|---|---|---|---|
| 5% | 15 | $2,400 | $4,350 |
| 10% | 30.25 | $4,840 | $8,772.50 |
| 15% | 50.5 | $8,080 | $14,645 |
| 20% | 75.5 | $12,080 | $21,895 |
| 30% | 131 | $20,960 | $37,990 |
Hypothetical example: Maria earned $900 a week, so two-thirds is $600 and her rate is capped at $290. At a 15% rating she would receive 50.5 weeks × $290 = $14,645. These figures illustrate the math only and aren’t a prediction for any real case.
Permanent disability is only one part of a settlement. Value also depends on future medical care and any temporary disability still owed. If your employer doesn’t offer regular, modified or alternative work, you may also qualify for a $6,000 Supplemental Job Displacement Benefit voucher for injuries on or after January 1, 2013. Run your own numbers with our workers’ comp calculator.
L4-L5 and L5-S1 disc injuries
There is no standard settlement amount for a lumbar disc injury. Two workers with the same MRI can end up with very different ratings. What moves the value is whether the herniation compresses a nerve root and the exam confirms it, whether you needed injections or surgery, your permanent restrictions, how much is apportioned to degeneration, your earnings, and whether future medical care stays open. Neck injuries follow the same logic; see neck and cervical spine injuries.
Future medical care and how you settle
A stipulated award pays your permanent disability and generally keeps future medical care open. A compromise and release pays a lump sum and usually closes future medical, so the amount must account for treatment you may need later. A workers’ comp judge must approve either one. See compromise and release vs. stipulated award. If an MRI your doctor recommended never happened, resolve that before you sign.
Protecting your claim step by step
- Report every symptom to your treating doctor, including radiating pain, numbness and weakness.
- Ask whether an RFA for an MRI was sent, and note the date.
- Watch the calendar. A routine UR decision is due within 5 business days.
- If you get a denial, file for IMR within 30 days, with your doctor’s supporting records.
- Get copies of the MRI report, RFA, every UR and IMR letter, and any QME or AME report discussing the imaging.
- Don’t settle on incomplete evidence. If testing is still pending, get advice before signing.
Frequently asked questions
Does a herniated disc increase my workers’ comp settlement?
It can, but not automatically. A herniation that matches your symptoms and exam, especially with nerve involvement or surgery, can support a higher rating. One the doctor considers old, or one without matching symptoms, may add little.
Can workers’ comp deny an MRI?
Yes. Utilization review can deny or modify a request it considers not medically necessary. You can request Independent Medical Review within 30 days, and your doctor can submit a new, better-documented request.
What if my MRI shows degeneration?
A degenerative finding doesn’t defeat your claim. It may lead a doctor to apportion part of your permanent disability to non-work causes, but the doctor must explain the reasoning, and that opinion can be challenged.
Does the IMR doctor examine me?
No. The decision rests on the medical records and reports submitted, which is why your doctor’s documentation matters.
Do I need an MRI before a QME exam?
Not always. A QME reviews your records, including any imaging, and examines you. If important imaging was denied or never done, raise it before the evaluation.
Talk to a California workers’ comp lawyer
Employees First Labor Law represents workers exclusively. If your MRI was denied or delayed, or a doctor is blaming your injury on degeneration, we offer free virtual consultations to review your records and options. Contact us or call (310) 853-3461.
This article is general information about California law as of 2026, not legal advice for your situation. Reading it does not create an attorney-client relationship.
