Utilization review (UR) is the process a claims administrator uses to decide whether treatment a doctor requests is medically necessary, and only a licensed physician can deny or modify a request for medical necessity reasons (Labor Code 4610(g)(3)(A)). When UR says no, the Labor Code sends the dispute to independent medical review (IMR), a review by an outside physician, instead of to a judge (Labor Code 4610.5(e)).
A utilization review denial lawyer in Orange County works that dispute from the denial letter forward. The Law Office of Jesse Melendrez represents injured workers in UR and IMR disputes, and in the liability disputes that sometimes sit underneath them.
What must a UR denial letter include?
A UR denial letter must give the reasons for the decision, the criteria or guidelines used, and the clinical reasons on medical necessity (Labor Code 4610(i)(5)). When the reviewer denies for missing information, the letter has to say what is missing and when the reviewer tried to reach the doctor.
For a request made before treatment, the written decision goes to the worker within two business days of the decision (Labor Code 4610(i)(4)(B)). With it comes a one-page IMR application, the DWC Form IMR (the version revised April 1, 2026), and an addressed envelope (Labor Code 4610.5(f); 8 CCR 9792.10.6(g)(1)).
What are the UR and IMR deadlines?
The deadlines are short and run from service of the paperwork.
| Step | Time limit | Source |
|---|---|---|
| UR decision, regular request | 5 business days from the request and supporting information; 14 days at most from the doctor’s recommendation | Labor Code 4610(i)(1) |
| UR decision, serious threat to health | 72 hours after the needed information | Labor Code 4610(i)(3) |
| IMR request | 30 days after service of the UR decision; 10 days for formulary drugs | Labor Code 4610.5(h)(1) |
| IMR decision | 30 days after the application and records arrive; 5 business days for an MTUS Drug List dispute; 3 days if expedited | Labor Code 4610.6(d); 8 CCR 9792.10.6(g) |
| Treatment after IMR overturns UR | Authorized within 5 working days | Labor Code 4610.6(j); 8 CCR 9792.10.7(a)(2) |
| Same request, no new facts | Denial stays in effect 12 months | Labor Code 4610(k) |
Sources: Labor Code 4610, 4610.5 and 4610.6 (leginfo, read October 8, 2026); 8 CCR 9792.10.6, as amended effective April 1, 2026, and 9792.10.7 (dir.ca.gov, read October 8, 2026).
Who decides an IMR?
An independent review organization under contract with the DWC decides it, through a physician reviewer who reads the records and rules on medical necessity under the state’s treatment guidelines (Labor Code 4610.5(c); 8 CCR 9792.10.6). The DWC’s current contractor is Maximus Federal Services, and employers pay the cost of the review (DWC; Labor Code 4610.6(l)).
The decision binds both sides (Labor Code 4610.6(g)). An appeal is a verified appeal filed with the WCAB within 30 days of the date the determination was mailed. The determination is presumed correct and is set aside only on clear and convincing proof of narrow grounds, such as fraud, a reviewer’s conflict of interest, bias, or a plainly wrong finding on a matter of ordinary knowledge (Labor Code 4610.6(h)).
When does a treatment denial go to a judge instead?
A treatment denial goes to a judge when the dispute is about more than medical necessity. If the claims administrator disputes liability for the injury or the body part, UR is not required and IMR waits until that dispute is resolved (Labor Code 4610(l), 4610.5(k)). That liability question goes to the WCAB, often with a QME.
Timing is the other route. The DWC’s Fact Sheet A says a claims administrator that misses the UR deadline cannot object to the doctor providing the treatment, and it points workers in that spot to an expedited hearing.
How does the firm work a UR denial?
We start with the paper, because the deadlines run from it.
- Read the UR letter against the Labor Code 4610 timeframes and notice rules, and pin down the service date that starts the 30 days.
- Confirm the IMR application and envelope came with it. Until they do, the IMR clock does not start (Labor Code 4610.5(h)(3)).
- Work with the treating doctor’s office on the reports and guidelines behind the request. The treating doctor may join the IMR request (Labor Code 4610.5(j)).
- File the IMR application with a copy of the UR decision, as the DWC instructs, and follow the case with Maximus.
- Take a liability dispute or a late UR decision to the WCAB instead.
Rules on the MPN, predesignation and changing doctors are on the medical treatment page, and every benefit is on the benefits page.
There is no upfront cost. Attorney fees in a California workers’ compensation case are set and approved by a workers’ compensation judge and are paid out of the benefits recovered. Whether a particular denial can be challenged depends on the medical record, which is what the first conversation looks at.
