“Very thankful for everything they did for us. Always responsive, reassured us every step of the way and obtained a great result.”
Miguel Orellana
✦ Certified Specialist in Workers’ Compensation Law — Certified by the State Bar of California, Board of Legal Specialization ✦
A denial is not the end. It’s the beginning of our fight for your benefits.
By Eman Yazdchi, Esq. · Certified Specialist in Workers' Compensation Law, State Bar of California Board of Legal Specialization
In California, a Simi Valley workers' comp denial runs on three clocks: §4610.5 IMR appeal in 30 days, §5903 Petition for Reconsideration in 25 days mailed / 20 electronic, and §5402(b) 90-day insurer decision presumption. Yazdchi Law, a Certified Specialist in Workers' Compensation Law firm, files these at the Simi Valley WCAB. Request a free case review.
Simi Valley workers' comp denial appeals run on three independent clocks. The §5402(b) 90-day insurer decision window under California Labor Code §5402 starts on DWC-1 filing — silence past 90 days converts to a presumption of compensability. The §4610.5 IMR appeal of a UR treatment denial starts on the UR decision date and runs 30 days. The §5903 Petition for Reconsideration on a WCJ adverse trial decision runs 25 days from mail service (20 days electronic). On a Simi Valley Hospital / Simi aerospace corridor denial file, all three clocks can be live simultaneously.
The §5402(c) one-day medical-treatment duty is the often-missed deadline. Under California Labor Code §5402, up to $10,000 of immediate medical treatment is owed within one day of the DWC-1 filing, regardless of whether the insurer is still inside the 90-day decision window. A Simi Valley insurer that misses the §5402(c) duty exposes a parallel §5814 25% penalty on the delay alongside the underlying denial fight. On a Simi Valley Hospital ICU nurse's patient-handling lumbar disability case, the §5402(c) record is often the cleanest §5814 trigger.
Yazdchi Law's office at 1125 W Avenue M-14, Suite A in Palmdale serves the Simi Valley WCAB on denied-claim files. Eman Yazdchi handles the §5402(b) presumption fight, the §4610.5 IMR cycle, and the §5903 Petition for Reconsideration phase, and is a Certified Specialist in Workers' Compensation Law, certified by the California Board of Legal Specialization, State Bar of California.
A denied Simi Valley workers' comp claim is built around five California Labor Code sections that do most of the work: California Labor Code §5402(b) (the 90-day decision-window presumption), California Labor Code §4610.5 (Independent Medical Review on UR denials), California Labor Code §5814 (the 25% penalty on unreasonable delay), California Labor Code §5900 (the framework section authorizing reconsideration), and California Labor Code §5903 (the 25-day/20-day Petition for Reconsideration deadline).
Under California Labor Code §5402(b), the 90-day insurer decision window starts on the day the Simi Valley worker files the DWC-1 — not the day the insurer receives it. On a Simi Valley Hospital ICU nurse's patient-handling lumbar disability case, the §5402(b) presumption is the strongest tool against a Simi Valley denial when the insurer dragged the QME process under California Labor Code §4062.2 or sat on a UR cycle under California Labor Code §4610 past the 90-day line. The presumption is rebuttable only by evidence the insurer could not have discovered with reasonable diligence during the 90 days — a high evidentiary bar at the Simi Valley district WCAB. Under California Labor Code §5402(c), the insurer also owes up to $10,000 in immediate medical treatment within one day of the DWC-1, regardless of the 90-day timer, and any delay on that duty surfaces a separate §5814 25% penalty exposure on the Simi Valley Hospital patient-handler spinal cases and Simi aerospace assembler cumulative-trauma claims record.
When a Simi Valley insurer's Utilization Review under California Labor Code §4610 denies treatment, the appeal route is Independent Medical Review under California Labor Code §4610.5 — 30 days from the UR decision, through Maximus, decided by an independent physician on the Medical Treatment Utilization Schedule standard. The IMR ruling binds the parties except on the five California Labor Code §4610.6 grounds: fraud, material conflict of interest, constitutionally-protected-basis bias, mistake of fact outside expert opinion, or plainly erroneous fact-finding. The WCAB cannot compel treatment authorization while IMR is pending — IMR is procedurally exclusive.
A Simi Valley workers' comp denial typically surfaces multiple §5814 25% penalty triggers under California Labor Code §5814 simultaneously. Each delayed benefit gets its own 25% penalty calculation: temporary disability under California Labor Code §4650 not paid on the bi-weekly schedule, medical treatment under California Labor Code §4600 not authorized within the §5402(c) one-day duty or after the §5402(b) 90-day decision-window lapsed, permanent disability advances under California Labor Code §4658 held past the regulatory schedule. The Simi Valley WCAB applies the penalty per-benefit after focused evidentiary findings on the delay record.
On a Simi Valley Hospital ICU nurse's patient-handling lumbar disability case, the Simi Valley Petition for Reconsideration under California Labor Code §5900 runs on the California Labor Code §5903 clock: 25 days from mail service of the adverse WCJ decision, 20 days if served electronically via EAMS under Title 8 CCR section 10605. The Petition specifies the §5903 grounds — newly discovered evidence, fraud, the WCJ acting without or in excess of powers, an unreasonable factual finding, an error of law, or insufficient or excessive findings. On Simi Valley Hospital / Simi aerospace corridor files, the most-cited grounds are unreasonable factual findings on §5402(b)-presumption rebuttal and errors of law on §4663 apportionment or §4660 occupational-variant calls. The WCAB either modifies or denies; denial opens the §5950 Writ of Review within 45 days.
Injured at work in Simi Valley? Call (661) 273-1780
Tap to call →Simi Valley denied-claim appeals are heard at the Oxnard district office of the Workers' Compensation Appeals Board at 1901 Outlet Center Drive, Suite 100, Oxnard, the district covering all of Ventura County. Yazdchi Law regularly appears at the Oxnard WCAB on denied-claim appeals, including those involving the California Labor Code §5402(b) 90-day presumption, the California Labor Code §5814 25% penalty, and the California Labor Code §5903 Petition for Reconsideration deadline. Related coverage: Simi Valley workers' comp claims.
The §5402(b) 90-day insurer decision window starts the day the Simi Valley worker files the DWC-1, not the day the insurer receives it. On a Simi Valley Hospital ICU nurse's patient-handling lumbar disability case, common Simi Valley Simi Valley Hospital healthcare and aerospace-corridor industry insurers hold the file open on QME-panel timing under California Labor Code §4062.2 or UR cycles under California Labor Code §4610 — both of which can blow past 90 days. Under California Labor Code §5402(b), once the window passes, the injury is presumed compensable, rebuttable only by reasonable-diligence evidence. Under California Labor Code §5402(c), $10,000 of immediate medical treatment is owed within one day of the DWC-1 regardless of the 90-day status.
The §5814 25% penalty record on a Simi Valley denial is built on the dated benefit-payment ledger: when temporary disability under California Labor Code §4650 was due, when it was paid, when treatment under California Labor Code §4600 was requested, when UR ruled, when the §5402(c) one-day medical duty triggered. On a Simi Valley aerospace-contractor's cumulative-trauma shoulder claim, each delay becomes a separate §5814 trigger. The Simi Valley Hospital patient-handler spinal cases and Simi aerospace assembler cumulative-trauma claims produces benefit-delay patterns that the Simi Valley WCAB sees frequently and rules on with focused evidentiary hearings.
Last reviewed by Eman Yazdchi, Esq., May 2026.
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