The 2026 Utilization Review Regulations: What Changed on April 1 and How to Challenge a Denial

The 2026 California UR regulations were filed with the Secretary of State on December 30, 2025 and took effect April 1, 2026. They amend a long list of sections in Title 8: 9767.6, 9781, 9785, 9785.6, 9786, the 9792.6 through 9792.15 series, and 9792.27.1 and 9792.27.17.

Start with what did not change. Labor Code section 4610 is intact. IMR is still the forum for medical necessity. The 30-day exemption and the formulary exemptions still exist.

What changed is the administrative layer built on top. There are new rules about who may issue a denial, when the decision clock starts, what an approval or denial letter must say, and how long a denial stays effective. For an applicant-side practice, the useful material is procedural, and most of it resolves into dates and documents that either exist in your file or do not.

If treatment has been denied on a California workers' compensation claim on or after April 1, 2026, the sections below run in the order you will need them: who was allowed to sign the decision, whether the request and the clock were handled correctly, what the letter had to contain, and how to appeal a UR denial through IMR within the applicable deadline.

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Who is allowed to deny

Section 9792.6.1 adds a definition of "non-physician reviewer," meaning an individual designated by the claims administrator or UR organization to assist in determining medical necessity. The same section specifies that a non-physician reviewer may not modify or deny a treatment request.

Section 9792.12 backs this up with monetary penalties, including for failure to ensure that only physician reviewers modify or deny treatment requests on medical necessity grounds, and for failure to ensure that only physician reviewers deny authorization when necessary information, testing, or consultation is missing.

This is the first thing to check on any adverse decision issued after April 1. Who signed it, and in what capacity. It is also the clearest example of what the 2026 California UR regulations did: they did not change the medical standard, they changed who and how.

The RFA question, and why DWC had to clarify it

The regulations removed the phrase "the DWC Form RFA" from several places, including the authorization definition in section 9792.6.1 and the receipt provisions in section 9792.9.1, replacing it with "request for authorization." That change generated enough confusion that DWC issued a newsline on May 14, 2026 to address it.

The clarification: section 9792.6.1 defines a request for authorization as a written request for a specific course of proposed medical treatment, and the regulations require it to be set forth on the DWC Form RFA found in section 9785.5, completed by the treating physician.

A narrative report can serve as the equivalent only if the claims administrator voluntarily agrees to accept it and the narrative identifies the employee and the requesting provider, identifies all recommended treatments specifically on the first page, includes substantiating documentation created no earlier than 30 days before the request, and carries the treating physician's signature. Electronic signatures are permitted by agreement of the parties.

Section 9792.9.1 adds a related duty. On receipt of a request that does not meet the definition of a complete request, the claims administrator or reviewer must either accept it as complete and comply with the requirements, or mark it "not complete" and return it to the requesting physician with the reasons for the return, no later than five business days from receipt. A request accepted as complete is subject to investigation and administrative penalties.

That five-business-day window is a date to capture. If a request came back marked not complete, note when. If it did not come back at all and no decision issued, that is a different problem for the claims administrator.

When the clock starts

Section 9792.9.3 clarifies that the first day in counting any timeframe requirement is the first normal business day or working day after receipt of the completed request, or of the request accepted as complete.

Section 9792.12 establishes penalties for failure to make timely decisions on non-expedited reviews within five working days of receiving the authorization request or the requested information, and for failure to issue written decisions within 72 hours on expedited review requests.

Together these give you the arithmetic for a timeliness challenge: date of receipt, first business day after, five working days or 72 hours, date the decision issued and was communicated.

The AB 1124 formulary exemption, and where it sits in the 2026 California UR regulations

AB 1124 (2015) directed the Administrative Director to establish an evidence-based drug formulary for the California workers' compensation system. The resulting MTUS Drug Formulary took effect January 1, 2018 and designates drugs on the MTUS Drug List as either exempt or non-exempt.

The practical distinction has not changed. A drug designated exempt may be prescribed without prospective utilization review where the prescription is consistent with the MTUS. A non-exempt drug requires prospective review before dispensing. The AB 1124 formulary exemption and the 30-day exemption are separate mechanisms that overlap, and conflating them is a common source of error on both sides.

Two points where the 2026 rulemaking touches this. The amended section list includes 9792.27.1 and 9792.27.17, both in the formulary series. And section 9792.9.4 now requires an approval of an exempt drug to say so on the face of the decision, which is addressed below.

Watch the interaction with section 9792.9.7. The 30-day exemption expressly excludes pharmaceuticals that are not expressly exempt under the MTUS Drug Formulary. A drug prescribed in the first 30 days after injury does not ride on the 30-day exemption unless it is separately exempt on the formulary. That is the most frequent misreading of the two provisions together.

The 30-day exemption as actually written

Section 9792.9.7 permits a treating physician to render medically necessary treatment without prospective UR for the first 30 days after the date of injury. The conditions are specific:

• The treatment is for a body part or condition the claims administrator has accepted as compensable
• The treatment is consistent with the applicable MTUS guideline
• The initial treating physician timely submits the Doctor's First Report of Occupational Injury or Illness (DIR Form 5021) with the anticipated treatment plan in detail
• All treatment anticipated in the first 30 days, including exempt drugs under the MTUS Drug Formulary, is set out in a request for authorization submitted concurrently with the Doctor's First Report
• Subsequent treating physicians in the 30-day period submit a request for authorization after their first visit, indicating all treatment being rendered
• The bill for non-emergency treatment is submitted within 30 days of the date of service, or within 180 days for emergency treatment

The exclusions matter as much as the conditions. Unless previously authorized or rendered as emergency treatment, the following fall outside the exemption: pharmaceuticals not expressly exempt under the MTUS Drug Formulary, non-emergency surgery in any setting, psychological and psychiatric treatment, home health care, imaging and radiology other than X-rays, DMEPOS where the purchase or rental cost for the expected course of treatment exceeds $250 under the OMFS (or where the billed amount exceeds $250 for an unlisted item), electrodiagnostic medicine, and spinal injections.

Two practical consequences. First, X-rays sit inside the exemption while other imaging sits outside it, so an early MRI dispute is not a 30-day exemption question. Second, the exemption depends on paperwork the treating physician has to file on time. A treating physician who did not submit the Doctor's First Report with the anticipated treatment plan, or who did not include the anticipated treatment in a concurrent RFA, has weakened the exemption regardless of the clinical merits.

Section 9792.9.7 also preserves retrospective review. If a claims administrator determines after retrospective review that a physician has a pattern and practice of rendering treatment inconsistent with the MTUS or the MTUS Drug Formulary, it may remove that physician's ability to render exempt treatment for any claim it administers, petition for change of primary treating physician, or terminate the physician from its MPN or health care organization.

What an approval letter must say

Section 9792.9.4 adds three drug and exemption labeling requirements:

• Where the RFA did not indicate "Do Not Substitute" or "Dispense as Written," a written decision approving the request in generic form must indicate that a generic substitute is authorized, or words to that effect
• Approval of a drug that is exempt on the Drug Formulary must indicate "Exempt per MTUS Drug Formulary," or words to that effect
• Approval of non-drug treatment exempt under section 9792.9.7 must identify the treatment as a "30-day exemption," or words to that effect

The third is a written acknowledgment that the exemption applied, and it is useful later if the same course of treatment gets contested.

What a denial must say, and how long it lasts

Section 9792.9.5 has two changes worth knowing.

The reviewer must engage with the treating physician's stated position.
Where the requesting physician has expressly opined that prerequisite treatment or criteria recommended under the applicable guidelines should be overlooked or is irrelevant to the requested treatment, the reviewing physician must explain why the requesting physician's explanation is insufficient.

Note the trigger. The duty arises when the treating physician expressly puts that opinion in the request. If the RFA is silent on why the guideline should not control, there is nothing the reviewer is required to answer. This is a drafting point for the treating physician at the front end.

A denial on medical necessity grounds now stays effective for 12 months.
Section 9792.9.5 specifies that a decision to modify or deny on the basis of medical necessity remains effective for 12 months from the date of the decision, without further action by the claims administrator, as to any further recommendation by the same physician, or another physician within that physician's practice group, for the same treatment. The exception is a further recommendation supported by a documented change in the facts material to the basis of the decision.

This is the most consequential change in the package for anyone handling repeat requests. Re-submitting the same request inside 12 months does not restart anything. The path runs through a documented change in material facts.

Section 9792.9.2 is the companion provision. A request for authorization that would otherwise be precluded from UR under Labor Code section 4610(k) cannot be deferred if the requesting physician expressly and unequivocally indicates or opines that there has been a change in facts material to the basis of the prior denial, and includes documentation of that change. Such a request must be reviewed by a physician reviewer, and any modification or denial must comply with section 9792.9.5.

Read those two together and the operational instruction is clear. A renewed request inside the 12-month window needs the treating physician to state the change in material facts expressly and unequivocally, and to attach the documentation supporting it. A renewed request that restates the original does not get a new review.

Section 9792.9.6 adds a smaller point: where a consultation by an expert reviewer is needed, the specialty of the expert reviewer to be consulted must be identified.

UR plans, URAC, and what is discoverable

Section 9792.7 was substantially rewritten. The parts that matter from the outside:

A UR plan that modifies or denies treatment must provide proof of URAC Workers' Compensation Utilization Management Accreditation, and must be submitted with DWC Form UR-01 carrying the medical director's signature. A claims administrator may submit a letter identifying the contracted URO instead of filing its own plan, where the URO has an approved plan on file. Material modifications, now defined to include changes in medical director, address, company name, or corporate structure, must be filed within 30 days with a certification of compliance. Section 9792.7(c) requires UR organizations to maintain current lists identifying the claims administrators for whom they perform UR functions.

Section 9792.7.1 incorporates the UR-01 form itself.

Section 9792.12 establishes penalties for failure to obtain Administrative Director approval of a plan before operating, failure to obtain or maintain URAC accreditation before starting or continuing UR functions, and failure to disclose or make available approved utilization review process descriptions and the accompanying written policies and procedures.

That last penalty is the one to remember. The approved UR process description and its written policies are something the claims administrator can be penalized for not making available.

Two tracks for challenging a denial under the 2026 California UR regulations

Under the Dubon II en banc framework, a UR decision is invalid and outside IMR only if it is untimely. Timeliness is a legal question for the WCAB. All other disputes about a UR decision go to IMR, and if UR is untimely the WCAB may determine medical necessity on substantial medical evidence consistent with Labor Code section 4604.5.

Track one, timeliness, goes to the WCAB.
When the completed request was received, when the clock started under 9792.9.3, whether the decision issued and was communicated inside five working days or 72 hours.

Track two, medical necessity, goes to IMR.
Whether the reviewer applied the MTUS correctly, whether the records were sufficient, whether the reviewing physician had the right expertise.

Where the new procedural requirements land is an open question. Whether a denial signed by a non-physician reviewer, or one that ignores the treating physician's express guideline argument, is defective in a way that reaches the WCAB rather than IMR has not been answered by published authority under these regulations. The argument will be made. It should not be the load-bearing element of a case strategy.

There is a related development worth tracking rather than relying on. Defense commentary in early 2026 raised whether the Dubon line could be challenged following the Second District's decision in Illinois Midwest Insurance Agency v. WCAB (Rodriguez), which ended the Patterson doctrine. That is commentary, not holding, and nothing has displaced Dubon II.

How to appeal a UR denial: IMR deadlines, precisely

Section 9792.10.1 sets the filing deadlines, and the DWC Form IMR effective April 1, 2026 states them on the form itself.

The application and a copy of the written determination letter go to Maximus Federal Services. A copy of the signed application goes to the claims administrator.

The deadlines run from the mailing date of the written determination letter:

• 30 days for all disputes, extended to 35 days if filed by mail, and to 40 days if filed by mail from outside California
• 10 days where the dispute involves only a drug listed on the MTUS Formulary Drug List, extended to 15 days if filed by mail, and to 20 days if filed by mail from outside California

Those mailing extensions are on the face of the form and are easy to miss.

The form now carries a field for the mailing date of the UR determination letter, marked with an asterisk, and checkboxes at the end designating which filing deadline applies. It also carries checkboxes for the type of review (regular, expedited, modification after appeal) and for three dispute categories: medication only under the MTUS Formulary Drug List, retrospective for exempt non-drug treatment, and retrospective for exempt drug treatment.

Here is the part worth building into intake. The form's own instructions state that the information on the form was filled in by the claims administrator, and that a recipient who believes any of it is incorrect should submit a separate sheet with the correct information. The claims administrator enters the mailing date and checks the deadline box. Both entries determine your client's window, and both should be verified against the letter and the envelope rather than accepted.

For expedited requests where the claims administrator did not perform an expedited review, the application must include a statement from the physician, supported by medical records, confirming the condition.

A working checklist when treatment is denied on a California workers' comp claim

1. Confirm who signed the decision, and whether a physician reviewer issued any modification or denial
2. Confirm the RFA was on the DWC Form RFA, or that the claims administrator agreed to accept a narrative meeting the content standards
3. If the request was returned as not complete, record whether that happened within five business days of receipt
4. Fix the clock: date of receipt, first business day after, five working days or 72 hours
5. If the 30-day exemption is in play, confirm the Doctor's First Report and the concurrent RFA were filed, and check the treatment against the exclusion list
6. If the treating physician expressly argued a guideline should not control, check whether the reviewer answered that argument
7. If this is a renewed request within 12 months of a prior medical necessity denial, confirm the treating physician expressly stated the change in material facts and attached documentation
8. Note the mailing date on the determination letter and calendar the applicable IMR deadline, including any mailing extension
9. Verify the claims administrator's entries on the IMR form against the letter itself
10. Request the applicable UR plan and the approved UR process description

Injured workers without counsel can reach a DWC information and assistance officer at 1-800-736-7401 for free help with the IMR process.

The underlying point

The 2026 California UR regulations did not create new grounds to win a medical necessity dispute. IMR still decides that. They created a longer list of things a decision must contain, a shorter list of people who may issue one, a 12-month bar on repeat requests, and a set of dates the claims administrator has to commit to in writing.

Every item on the checklist above is a documentation question, and the answers live in the RFA, the Doctor's First Report, the correspondence file, the determination letter, and the service dates. A challenge built on a reconstructed timeline is a weak challenge. A challenge built on a complete, chronologized record with verified dates is the version that survives a hearing.

EWORD Solutions handles records retrieval, subpoena management, and medical chronologies for California workers' compensation firms. If your team is rebuilding UR timelines from scratch on every disputed file, we can take that off your desk.

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