2nd District Court of Appeal Rejects Patterson Exception to UR/IMR

In an important development, the well-known Patterson case has been reversed by a Court of Appeal. Patterson is the significant panel decision that held that certain types of continuing care were not subject to utilization review (UR) and independent medical review (IMR). This decision, Illinois Midwest Insurance Agency LLC v. WCAB (Rodriguez) has held that the Patterson reasoning was inapposite of the statutory language, and has subjected continuing care to UR/IMR.

BACKGROUND

With the enactment of Senate Bill 863 in 2012, the California Legislature established the independent medical review (IMR) process. It became effective for all treatment requests Jan. 1, 2013. The IMR process replaced judicial review as the method to appeal UR decisions regarding all proposed medical care. Under the statutory scheme, all proposed medical care is to be requested by a physician submitting a request for authorization (RFA). That request is reviewed by UR, and may be appealed only to IMR. Judicial review of such care for reasonableness was no longer allowed (later case law established the sole exception — being for late UR).

It represented a dramatic change from the previous free-for-all litigation over medical treatment. It was embraced by the employer community, and often despised by those representing applicants. It was a deliberate change. In adopting SB 863, the Legislature found the former system for resolving disputes over the medical necessity of treatment to be “costly, time consuming, and [did] not uniformly result in the provision of treatment that adhere[d] to the highest standards of evidence-based medicine, [which] adversely affect[ed] the health and safety of workers injured in the course of employment.” (SB 863 2011–2012 Regular Session § 1(d).) The Legislature believed that establishing “independent medical review and [providing] for limited appeal of decisions … [was] a necessary exercise of the Legislature's plenary power to provide for the settlement of any disputes arising under the workers' compensation laws of this state." (§ 1(g).)

But in short order an exception was carved out by the WCAB. In 2014, in the significant panel decision of Patterson v. The Oaks Farm (2014) 79 CCC 910, the board carved out a significant exception for "ongoing" or "continual" medical treatment. Under the Patterson doctrine, if an employer previously had authorized a type of treatment, it could not use UR to deny a subsequent request for the same treatment without first proving that there had been a change in circumstances or condition showing that the services were no longer reasonably required to cure or relieve the injured worker from the effects of the industrial injury. In that and subsequent panel cases, the WCAB held that UR of previously authorized care was not permitted until defendants could meet their burden of proving a change of circumstances or condition. It effectively returned jurisdiction over a large class of medical necessity disputes back to the WCAB.

On Nov. 10, 2025, however, the 2nd District Court of Appeal issued its published decision in Illinois Midwest Insurance Agency LLC v. WCAB (Rodriguez), which squarely rejects that exception. The court held that there is no statutory basis for an "ongoing treatment" exception to the UR/IMR process. For any dispute over medical necessity arising from a UR decision, IMR is the sole and exclusive remedy.

FACTS OF THE CASE

The applicant sustained a catastrophic industrial brain injury in 2016, and required ongoing home health care. In September 2018, his primary treating physician submitted requests for authorization in six-week increments. For more than a year, the defendant authorized the care, sometimes through the claims adjuster and sometimes after sending the requests to UR. In September 2019, the defendant sent a new request to UR, which issued a timely denial based on medical necessity.

Instead of seeking IMR, the applicant filed for an expedited hearing before the WCAB. The WCJ, relying on Patterson, found that the WCAB had jurisdiction because the care was "ongoing and constant." The WCJ ruled that the defendant could not terminate the treatment without a showing of substantive medical evidence that there was a change in the applicant's condition, and ordered the care to be provided. The WCAB affirmed the WCJ's decision on reconsideration, prompting the defendant to file a petition for a writ of review.

COURT OF APPEAL'S DECISION

The Court of Appeal annulled the WCAB's decision. The court found that the WCAB's reliance on Patterson to create an exception to IMR for ongoing treatment was a "misplaced" interpretation of the law. It rejected Patterson to the extent that it created a general exception to UR and IMR procedures for “ongoing” or “continual” treatment as inconsistent with the statutory framework.

The court noted that Patterson involved an employer's authorization of nurse case manager services, and did not involve a treatment request that proceeded to UR, so Patterson was neither instructive nor persuasive for the current case. It noted that Patterson was not confronted with the question of whether the WCAB would have jurisdiction over an adverse medical necessity determination, made by a medical professional, in a statutorily mandated UR process. Be that as it may, the rationale underlying Patterson was not accepted.

As the court explained, "The entire statutory framework evinces a clear legislative purpose: to remove medical necessity determinations from the WCAB and courts and to place such decisions exclusively in the hands of medical professionals." The court's reasoning was grounded in the unambiguous language of Labor Code § 4610.5, which mandates that any dispute over a UR decision must be resolved "only in accordance with this section" — that is, through IMR. The court explained, "The entire statutory framework evinces a clear legislative purpose: to remove medical necessity determinations from the WCAB and courts and to place such decisions exclusively in the hands of medical professionals." The court found no statutory authority for the exception adopted by the WCAB.

The court ruled that the WCAB erred in construing summary denials of other petitions as approval of Patterson. It stated, "A summary denial of a petition for judicial review of an Appeals Board ruling decides no issues and has no precedential value."

The court explicitly rejected the argument that once treatment is approved, an employer may not use UR for subsequent requests. It reasoned that the duration of treatment and the necessity of ongoing treatment are medical issues, and applying the reasoning of Patterson to any ongoing medical treatment would frustrate the purpose of the UR and IMR processes. The court concluded that the applicant's failure to request IMR after the UR denial was fatal to his challenge, as the WCAB lacked jurisdiction to hear the dispute.

ANALYSIS

The Rodriguez decision is a landmark ruling that closes the door on the Patterson exception for any dispute originating from a UR denial. It reaffirms the exclusivity of the UR/IMR process, and dismantles a widely used strategy to circumvent IMR, and bring medical necessity disputes back before the WCAB.

For defense practitioners, this decision reinforces that the statutory UR/IMR process applies to all treatment requests submitted by a physician, including subsequent requests for ongoing care. An employer is not estopped from sending a new request for previously authorized care to UR, and there is no need to first litigate a "change in circumstances" at the trial level. Of course, it remains crucial for defendants to make sure requests for care are timely decided through the UR process.

For applicants' attorneys, the decision establishes that following a UR denial, IMR is a mandatory and non-negotiable step. The strategy of challenging a UR denial for ongoing care through an expedited hearing is no longer viable. Failing to timely request IMR will result in the forfeiture of the applicant's right to challenge the denial.

FOOTNOTE 6 — WHAT ISN'T DECIDED

Crucially, in footnote 6, the court limited its holding to the specific facts before it — a UR denial of a new request for treatment for a specific duration. The court explicitly did not decide whether a different analysis applies when, for example, an employer authorizes treatment, and subsequently terminates the treatment without using the UR process, or when the parties stipulate to the terms of treatment and agree to forgo the UR/IMR procedure. This leaves a potential door open for WCAB jurisdiction for some different, more limited set of circumstances.

The court also did not address the scenario when treatment was authorized for an unlimited duration or without a specific duration. Although defendants can argue that they have the right to conduct UR to determine whether ongoing care is medically necessary in those cases, the WCAB potentially could require them to show a material change in the applicant's condition before they could be allowed to conduct UR pursuant to Patterson.

WHAT HAPPENS NOW

Although Rodriguez now replaces Patterson as the law of the land, it should be noted that there might be more to the story. Multiple appeals are pending in more than one appeals court district. Contrary or affirming decisions might be issued in the future, and it's even possible that the California Supreme Court will hear the issue.

But for now, in continuing care cases, employers are sure to await the next RFA, and submit it to UR with the full knowledge that IMR is the applicant's only remedy if, indeed, the care is timely denied. There are probably thousands of such cases. Rodriguez is a statement of existing law, and, as such, we will probably see claims examiners reviewing their inventory for the opportunity to combat care they see as possibly misaligned with UR standards.

What could happen in cases in which a judicial order, award or finding has become final? Rodriguez establishes the rules moving forward, but how will they apply to prior decisions in which the WCAB has determined, pursuant to Patterson, an applicant's entitlement to previously authorized care? No doubt, defendants will submit a petition to reopen, pleading to set aside based on a mistake of law.

A lot could depend on the exact wording of the finding. In many cases, the WCAB has specifically determined that no more RFAs are accepted or UR allowed until and unless the employer meets the burden of proving a change in the employee's circumstances or condition. When the order has become final and appeals exhausted, does it still have jurisdiction to reverse that finding?

It seems so for most cases. Generally, a petition to set aside an award may be filed only within five years from the date of injury, absent extrinsic fraud, although the WCAB does have continuing jurisdiction over continuing medical care awards. The Court of Appeal has stated, "There is a recognized exception to the doctrine of the law of the case where, ... there has been an intervening change or clarification in the law by the higher courts." (Messner v. IAC (1963) 216 Cal. App. 2d 536, 541.) Also, it has stated, "It is clear that a subsequent judicial interpretation of the compensation statutes contrary to a prior administrative interpretation is 'good cause' to reopen a case under section 5803 of the Labor Code, if the request to reopen is made within five years from the date of injury." (Knowles v. WCAB (1970) 10 Cal. App. 3d 1027, 1030.)

So, defendants can assert that the WCAB's prior decisions to follow Patterson were invalid. But they might need to proactively challenge the prior awards through litigation. They might have a much tougher time of it if the five years have passed, depending on the facts.

For further discussion of Patterson and its application, see "Sullivan on Comp" Section 7.2 Scope of Care — Cure or Relieve.

For further discussion of the UR and IMR process, see the "Sullivan on Comp" sections starting with Section 7.30 Utilization Review and Independent Medical Review — History.

For further discussion of the WCAB's grounds for setting aside an award, see "Sullivan on Comp" 6.27 Five-Year Statute — Reopening for Good Cause.