As the Legislature printed it
DIVISION 4. WORKERS' COMPENSATION AND INSURANCE [3200 - 6002] · PART 2. COMPUTATION OF COMPENSATION [4451 - 4856] · CHAPTER 2. Compensation Schedules [4550 - 4856] · ARTICLE 2. Medical and Hospital Treatment [4600 - 4615]
(a) This section applies to the following disputes: (1) Any dispute over a utilization review decision regarding treatment for an injury occurring on or after January 1, 2013. (2) Any dispute over a utilization review decision if the decision is communicated to the requesting physician on or after July 1, 2013, regardless of the date of injury. (3) Any dispute occurring on or after January 1, 2018, over medication prescribed pursuant to the drug formulary adopted pursuant to Section 5307.27. (b) A dispute described in subdivision (a) shall be resolved only in accordance with this section. (c) For purposes of this section and Section 4610.6, the following definitions apply: (1) “Disputed medical treatment” means medical treatment that has been modified or denied by a utilization review decision on the basis of medical necessity. (2) “Medically necessary” and “medical necessity” mean medical treatment that is reasonably required to cure or relieve the injured employee of the effects of his or her injury and based on the following standards, which shall be applied as set forth in the medical treatment utilization schedule, including the drug formulary, adopted by the administrative director pursuant to Section 5307.27: (A) The guidelines, including the drug formulary, adopted by the administrative director pursuant to Section 5307.27. (B) Peer-reviewed scientific and medical evidence regarding the effectiveness of the disputed service. (C) Nationally recognized professional standards. (D) Expert opinion. (E) Generally accepted standards of medical practice. (F) Treatments that are likely to provide a benefit to a patient for conditions for which other treatments are not clinically efficacious. (3) “Utilization review decision” means a decision pursuant to Section 4610 to modify or deny, based in whole or in part on medical necessity to cure or relieve, a treatment recommendation or recommendations by a physician prior to, retrospectively, or concurrent with, the provision of medical treatment services pursuant to Section 4600 or subdivision (c) of Section 5402. “Utilization review decision” may also mean a determination, occurring on or after January 1, 2018, by a physician regarding the medical necessity of medication prescribed pursuant to the drug formulary adopted pursuant to Section 5307.27. (4) Unless otherwise indicated by context, “employer” means the employer, the insurer of an insured employer, a claims administrator, or a utilization review organization, or other entity acting on behalf of any of them. (d) If a utilization review decision denies or modifies a treatment recommendation based on medical necessity, the employee may request an independent medical review as provided by this section. (e) A utilization review decision may be reviewed or appealed only by independent medical review pursuant to this section. Neither the employee nor the employer shall have any liability for medical treatment furnished without the authorization of the employer if the treatment is modified or denied by a utilization review decision, unless the utilization review decision is overturned by independent medical review in accordance with this section. (f) As part of its notification to the employee regarding an initial utilization review decision based on medical necessity that denies or modifies a treatment recommendation, the employer shall provide the employee with a one-page form prescribed by the administrative director, and an addressed envelope, which the employee may return to the administrative director or the administrative director’s designee to initiate an independent medical review. The employee may also request independent medical review electronically under rules adopted by the administrative director. The employer shall include on the form any information required by the administrative director to facilitate the completion of the independent medical review. The form shall also include all of the following: (1) Notice that the utilization review decision is final unless the employee requests independent medical review. (2) A statement indicating the employee’s consent to obtain any necessary medical records from the employer or insurer and from any medical provider the employee may have consulted on the matter, to be signed by the employee. (3) Notice of the employee’s right to provide information or documentation, either directly or through the employee’s physician, regarding the following: (A) The treating physician’s recommendation indicating that the disputed medical treatment is medically necessary for the employee’s medical condition. (B) Medical information or justification that a disputed medical treatment, on an urgent care or emergency basis, was medically necessary for the employee’s medical condition. (C) Reasonable information supporting the employee’s position that the disputed medical treatment is or was medically necessary for the employee’s medical condition, including all information provided to the employee by the employer or by the treating physician, still in the employee’s possession, concerning the employer’s or the physician’s decision regarding the disputed medical treatment, as well as any additional material that the employee believes is relevant. (g) The independent medical review process may be terminated at any time upon the employer’s written authorization of the disputed medical treatment. Notice of the authorization, any settlement or award that may resolve the medical treatment dispute, or the requesting physician withdrawing the request for treatment, shall be communicated to the independent medical review organization by the employer within five days. (h) (1) The employee may submit a request for independent medical review to the division. The request may be made electronically under rules adopted by the administrative director. The request shall be made no later than as follows: (A) For formulary disputes, 10 days after the service of the utilization review decision to the employee. (B) For all other medical treatment disputes, 30 days after the service of the utilization review decision to the employee. (2) If at the time of a utilization review decision the employer is also disputing liability for the treatment for any reason besides medical necessity, the time for the employee to submit a request for independent medical review to the administrative director or administrative director’s designee is extended to 30 days after service of a notice to the employee showing that the other dispute of liability has been resolved. (3) If the employer fails to comply with subdivision (f) at the time of notification of its utilization review decision, the time limitations for the employee to submit a request for independent medical review shall not begin to run until the employer provides the required notice to the employee. (4) A provider of emergency medical treatment when the employee faced an imminent and serious threat to his or her health, including, but not limited to, the potential loss of life, limb, or other major bodily function, may submit a request for independent medical review on its own behalf. A request submitted by a provider pursuant to this paragraph shall be submitted to the administrative director or administrative director’s designee within the time limitations applicable for an employee to submit a request for independent medical review. (i) An employer shall not engage in any conduct that has the effect of delaying the independent review process. Engaging in that conduct or failure of the employer to promptly comply with this section is a violation of this section and, in addition to any other fines, penalties, and other remedies available to the administrative director, the employer shall be subject to an administrative penalty in an amount determined pursuant to regulations to be adopted by the administrative director, not to exceed five thousand dollars ($5,000) for each day that proper notification to the employee is delayed. The administrative penalties shall be paid to the Workers’ Compensation Administration Revolving Fund. (j) For purposes of this section, an employee may designate a parent, guardian, conservator, relative, or other designee of the employee as an agent to act on his or her behalf. A designation of an agent executed prior to the utilization review decision shall not be valid. The requesting physician may join with or otherwise assist the employee in seeking an independent medical review, and may advocate on behalf of the employee. (k) The administrative director or his or her designee shall expeditiously review requests and immediately notify the employee and the employer in writing as to whether the request for an independent medical review has been approved, in whole or in part, and, if not approved, the reasons therefor. If there appears to be any medical necessity issue, the dispute shall be resolved pursuant to an independent medical review, except that, unless the employer agrees that the case is eligible for independent medical review, a request for independent medical review shall be deferred if at the time of a utilization review decision the employer is also disputing liability for the treatment for any reason besides medical necessity. (l) Upon notice from the administrative director that an independent review organization has been assigned, the employer shall electronically provide to the independent medical review organization under rules adopted by the administrative director a copy and list of all of the following documents within 10 days of notice of assignment: (1) A copy of all of the employee’s medical records in the possession of the employer or under the control of the employer relevant to each of the following: (A) The employee’s current medical condition. (B) The medical treatment being provided by the employer. (C) The request for authorization and utilization review decision. (2) A copy of all information provided to the employee by the employer concerning employer and provider decisions regarding the disputed treatment. (3) A copy of any materials the employee or the employee’s provider submitted to the employer in support of the employee’s request for the disputed treatment. (4) A copy of any other relevant documents or information used by the employer or its utilization review organization in determining whether the disputed treatment should have been provided, and any statements by the employer or its utilization review organization explaining the reasons for the decision to deny or modify the recommended treatment on the basis of medical necessity. The employer shall concurrently provide a copy of the documents required by this paragraph to the employee and the requesting physician, except that documents previously provided to the employee or physician need not be provided again if a list of those documents is provided. (m) Any newly developed or discovered relevant medical records in the possession of the employer after the initial documents are provided to the independent medical review organization shall be forwarded immediately to the independent medical review organization. The employer shall concurrently provide a copy of medical records required by this subdivision to the employee or the employee’s treating physician, unless the offer of medical records is declined or otherwise prohibited by law. The confidentiality of medical records shall be maintained pursuant to applicable state and federal laws. (n) If there is an imminent and serious threat to the health of the employee, as specified in subdivision (c) of Section 1374.33 of the Health and Safety Code, all necessary information and documents required by subdivision (l) shall be delivered to the independent medical review organization within 24 hours of approval of the request for review. (o) The employer shall promptly issue a notification to the employee, after submitting all of the required material to the independent medical review organization, that lists documents submitted and includes copies of material not previously provided to the employee or the employee’s designee. (p) The claims administrator who issued the utilization review decision in dispute shall notify the independent medical review organization if there is a change in the claims administrator responsible for the claim. Notice shall be given to the independent medical review organization within five working days of the change in administrator taking effect.
How panels applied this section
Newest released decisions whose legal-standard extraction named this section. Each quotes the passage and links to the official PDF. Unofficial guide — not legal advice.
- ADJ15211632 · 2026-06-25 · San Diego District Office§ 4610.5
Determinative passage · p.9We further observe that under the auspices of California's workers' compensation system, questions relating to the medical necessity of a treatment requested by a physician are decided through compulsory UR and IMR processes. Section 4610 requires that employers establish a UR process. (Lab. Code, § 4610; State Comp. Ins. Fund v. Workers' Comp. Appeals Bd. (Sandhagen) (2008) 44 Cal.4th 230, 241 ("Sandhagen").) Once a treating physician submits an RFA to an employer, the employer must either approve the treatment request or dispute the treatment request and submit the matter for review. When an employer chooses to challenge a treatment request, a UR physician will evaluate whether the requested treatment is "medically necessary," and will either: (1) approve; (2) modify; or (3) deny the requested medical treatment. (Lab. Code, § 4610, subds. (a), (c), (e) & (g)(4).) UR must be accomplished within strict time limits. (Id.; see Dubon v. World Restoration ("Dubon") (2014) 79 Cal.Comp.Cases 1298, 1306 (Appeals Board en banc).)
The Board reviewed the timeliness and medical necessity of the UR decisions and the applicability of the UR bar to subsequent RFAs.
Official decision · page 9 → - ADJ19186265 · 2026-05-26 · Los Angeles District Office§ 4610.5
Determinative passage · p.1Applicant contends that defendant did not meet their burden of proof that they complied with the timeframes required for expedited review of an RFA pursuant to Labor Code section 4610.5.0F1 Applicant also contends that there was not a change of circumstance warranting the RFA for recertification and that not providing a safe discharge plan is contrary to the Labor Code.
The Board applied this statute to determine the timeliness and jurisdiction of the expedited review.
Official decision · page 1 → - ADJ11422165 · 2026-02-24 · Sacramento District Office§ 4610.5
Determinative passage · p.4therapy and medication, standing alone, is a sufficient basis for the provision of future medical treatment. (See, e.g., Argonaut Insurance Co. v. Workers' Comp. Appeals Bd. (Garcia) (1996) 61 Cal.Comp.Cases 378 (writ den.); County of Los Angeles v. Workers' Comp. Appeals Bd. (Garcia) (1995) 60 Cal.Comp.Cases 617 (writ den.).) We further observe that the medical necessity of any such request for future medical treatment would be subject to the utilization review and independent medical review processes described in Labor Code2 sections 4610 and 4610.5.
Referenced as procedural safeguards for future medical treatment disputes.
Official decision · page 4 → - ADJ15245137 · 2026-01-09 · Van Nuys District Office§ 4610.5
Determinative passage · p.6(Lab. Code, § 4610; State Comp. Ins. Fund v. Workers' Comp. Appeals Bd. (Sandhagen) (2008) 44 Cal.4th 230, 236.) Section 4610.5 makes IMR applicable to "any dispute over a utilization review decision," and requires that any such dispute, "shall be resolved only" by IMR. The Medical Unit reviews UR plans and the IMR programs used to resolve disputes about medical treatment and medical legal billing. The AD, although not a party to this action, is charged with oversight of Medical Unit programs that provide care to injured workers.
Establishes IMR as the exclusive dispute resolution for UR decisions.
Official decision · page 6 → - ADJ8948890 · 2025-10-07 · Los Angeles District Office§ 4610.5
Determinative passage · p.5Turning now to the merits of the Petition, it is well established that "[w]here a lien claimant (rather than the injured employee) is litigating the issue of entitlement to payment for industrially- related medical treatment, the lien claimant stands in the shoes of the injured employee and the lien claimant must prove by preponderance of the evidence all of the elements necessary to the establishment of its lien." (Kunz v. Patterson Floor Coverings, Inc. (2002) 67 Cal.Comp.Cases 1588, 1592 (Appeals Bd. en banc).) Section 5705 provides that "[t]he burden of proof rests upon the party or lien claimant holding the affirmative of the issue." Accordingly, the lien claimant carries the "affirmative burden of proving that its lien is reasonable, and it must carry this burden by a preponderance of the evidence. (Lab. Code, § 5705; 3202.5; Tapia v. Skill Masters Staffing (2008) 73 Cal.Comp.Cases 1338, 1342§ 1343 (Appeals Bd. en banc).)
Applied to require Reliable Medical Supply to prove the necessity and reasonableness of the medical treatment provided.
Official decision · page 5 → - ADJ16034617 · 2025-08-12 · Van Nuys District Office§ 4610.5
Determinative passage · p.6Every employer is required to establish a utilization review process for screening, reviewing, and deciding on treatment recommendations that are made by an employee's physician. (§ 4610, subds. (a) & (b).) Any decision to modify, delay, or deny a request for medical treatment for a work-related injury must be made by a licensed physician pursuant to a utilization review process. (§ 4610, subd. (e).) The utilization review process must be governed by written policies and procedures that are based on medical necessity and consistent with the "schedule for medical treatment utilization" adopted pursuant to section 5307.27.2 (§ 4610, subd. (c).) The employer must make its decision on treatment in a timely fashion, but not to exceed five working days from receipt of the information necessary to make the determination, and not more than 14 days from the date of the request by the employee's physician. (§ 4610, subd. (g)(1).) If the utilization review approves the requested treatment, the determination is final and the employer may not challenge it. (§ 4610.5, subd. (f)(1).)
The UR process must be timely and based on medical necessity; a certified UR determination is final and not subject to employer challenge.
Official decision · page 6 → - ADJ9712319 · 2025-06-20 · Sacramento District Office§ 4610.5
Determinative passage · p.8In its final argument, Petitioner contends that it "could not logically be the legislative intent for IMR to be utilized for non-substantive denials." The petitioner incorrectly asserts that any UR determination-regardless of its compliance with statutory and regulatory requirements-must proceed to IMR. This interpretation is legally flawed. The statutory IMR process (Lab. Code§ 4610.5-4610.6) is predicated on a valid and substantively reviewed UR decision. A UR determination that fails to meet the legal standards for timeliness, medical review, or adequacy is not a valid decision and therefore cannot trigger IMR. The Legislature could not have intended that defective or procedurally invalid UR denials serve as a basis for IMR. Doing so would improperly shift the burden to the injured worker and deprive the WCAB of its fundamental adjudicatory role.
IMR process requires a valid and substantively reviewed UR decision; defective UR denials cannot trigger IMR.
Official decision · page 8 → - ADJ17674030 · 2024-12-30 · Riverside District Office§ 4610.5
Determinative passage · p.6Lien claimant has the burden to prove that the treatment rendered was reasonable and necessary to cure or relieve from the effects of the industrial injury. (§ 4600, 4610.5(c)(2); 5705.)
Applied to defer reasonableness of treatment pending completion of UR/IMR process.
Official decision · page 6 →
All 22 decisions naming § 4610.5 →
The rules written under this section
A statute says what is owed; Title 8 says by when, on what form, and what happens if the deadline passes. These name § 4610.5as what they implement.
- 8 CCR § 35.5Compliance by AMEs and QMEs with Administrative Director Evaluation and Reporting Guidelines.
- 8 CCR § 9785Reporting Duties of the Primary Treating Physician.
- 8 CCR § 10451.2Determination of Medical Treatment Disputes. [Repealed]repealed
- 8 CCR § 10606Physicians' Reports as Evidence. [Renumbered]repealed
- 8 CCR § 10770Filing and Service of Lien Claims. [Repealed]repealed
- 8 CCR § 10862Filing and Service of Lien Claims and Supporting Documents.
- 8 CCR § 10863Verification of Compliance with Labor Code Section 4903.6 on Filing of Lien Claim or Application by Lien Claimant.
- 8 CCR § 10872Notification of Resolution or Withdrawal of Lien Claims.
Also on this
Unofficial guide — not legal advice. The statute is the state’s text. The quotes are litigated applications, not a prediction.
About California Labor Code § 4610.5
What is California Labor Code § 4610.5?
Labor Code § 4610.5 sits in ARTICLE 2. Medical and Hospital Treatment [4600 - 4615]. The statute on this page begins: (a) This section applies to the following disputes: (1) Any dispute over a utilization review decision regarding treatment for an injury. The official display is on LegInfo; this is a reprint.
Did WCAB panels apply Labor Code § 4610.5 in this corpus?
This corpus has 22 released decisions whose extracted legal standards named § 4610.5. Quotes and PDFs are on this page. That is not every case in California that ever cited the section.