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✦ 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 denied Lancaster workers' comp claim is overturned through the §5402(b) 90-day presumption, an IMR appeal under §4610.5, or a Petition for Reconsideration under §5903 (25 mailed / 20 electronic). Yazdchi Law, a Certified Specialist firm, handles Antelope Valley Hospital / Edwards-corridor denial files at the Lancaster WCAB. Request a free case review.
An Antelope Valley Hospital nurse's patient-handling lumbar disability fight typically receives a Lancaster workers' comp denial in one of three forms: a §5402 written-denial letter inside the 90-day window contesting AOE-COE; silence past the 90-day decision window — triggering the §5402(b) presumption-of-compensability under California Labor Code §5402 — and a parallel UR denial of treatment authorization under California Labor Code §4610 routing to IMR under California Labor Code §4610.5. A Lancaster aerospace-contractor's cumulative-trauma claim usually carries the same three-pattern denial profile.
The denial-appeal route differs by form. The §5402(b) presumption is litigated at the Lancaster WCAB through an Application for Adjudication; the §4610 UR denial routes to IMR through Maximus on a 30-day clock with a binding decision under California Labor Code §4610.6; the §5402 written denial is litigated at the Lancaster WCAB on the merits of AOE-COE. On the Antelope Valley Hospital / Edwards-corridor corridor, all three routes can run in parallel on a single healthcare, retail/warehouse, and Edwards-corridor support work file.
Yazdchi Law's office at 1125 W Avenue M-14, Suite A in Palmdale serves the Lancaster 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 Lancaster 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), once an injured Lancaster worker files a DWC-1 claim form, the insurer has 90 days to accept or deny the claim. If the insurer misses the 90-day window, the injury is presumed compensable — and that presumption can only be rebutted by evidence the insurer could not have discovered with reasonable diligence during the 90 days. On an Antelope Valley Hospital nurse's patient-handling lumbar disability fight, the §5402(b) presumption is leverage because Antelope Valley Hospital / Edwards-corridor insurers routinely sit on a DWC-1 while waiting on a QME panel under California Labor Code §4062.2 or a UR cycle under California Labor Code §4610 — both of which can blow past the 90-day window. California Labor Code §5402(c) also requires up to $10,000 in immediate medical treatment within one day of the DWC-1, regardless of the 90-day status — a Lancaster delay on the §5402(c) duty surfaces a separate §5814 25% penalty.
When a Lancaster 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 Lancaster 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 Lancaster WCAB applies the penalty per-benefit after focused evidentiary findings on the delay record.
On a Lancaster aerospace-contractor's cumulative-trauma claim, a Petition for Reconsideration under California Labor Code §5900 is filed at the Lancaster district WCAB within 25 days of mail service of the workers' comp judge's adverse decision (20 days if served electronically via EAMS under Title 8 CCR section 10605). On the typical Antelope Valley Hospital / Edwards-corridor denial appeal, the Petition identifies one or more of the §5903 grounds: newly discovered evidence on the Antelope Valley Hospital patient-handling spinal injuries, AV Mall delivery-corridor back cases, and cumulative-trauma on long-tenure aerospace-contract workers, an unreasonable factual finding on the §5402(b) presumption or the QME apportionment under California Labor Code §4663, or an error of law on the §5402(c) one-day duty or the §5814 penalty record. The WCAB either grants reconsideration and modifies the decision, or denies. A denial opens the Writ of Review path under California Labor Code §5950 within 45 days.
Injured at work in Lancaster? Call (661) 273-1780
Tap to call →All denied Lancaster workers' comp claims are litigated at the Van Nuys WCAB at 6150 Van Nuys Blvd. This office handles Declarations of Readiness, Mandatory Settlement Conferences, and Trials. Our firm appears before Van Nuys judges regularly and understands the evidentiary standards each judge applies. Related coverage: Lancaster workers' comp claims. See also: California school district workers' comp hub.
There is no strict deadline to challenge a workers' comp denial, but acting quickly is critical. Medical evidence degrades over time, witnesses become unavailable, and the insurer has no obligation to pay benefits during the dispute period. Contact an attorney as soon as you receive a denial letter to begin building your case for the Van Nuys WCAB. Related coverage: Lancaster workers' comp retaliation claims.
If your claim is denied, the insurer is not required to authorize ongoing treatment. However, if you filed a DWC-1 and the insurer denied after the 90-day window, the presumption of compensability under LC §5402 means treatment should continue. We intervene to ensure Lancaster workers receive medical care while their denied claims are being litigated.
Last reviewed by Eman Yazdchi, Esq., May 2026.
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