I agree with the majority’s conclusion and much of its analysis. Specifically, I agree that the “utilization review” process set forth in Labor Code1 section 4610 is mandatory. I also agree that, if an employer fails to meet section 4610’s deadlines, it may not object to the employee’s requested medical treatment under section 4062. Certain language in the majority’s opinion, however, might be misread to suggest that utilization review is a dispute-resolution process that replaces the “cumbersome, lengthy, and potentially costly” dispute-resolution process that previously applied under former section 4062. (Maj. opn., ante, at p. 238.) As I understand the statutory scheme, the utilization review process adds a new step that the employer must take before section 4062 comes into play, but it does not replace the section 4062 process. Section 4062 remains the means for resolving any dispute between the parties regarding medical treatment, as I explain below.
Section 4600 requires employers to provide their employees with medical treatment for their work-related injuries. When disputes arise regarding the conclusions and recommendations of the treating physician, section 4062 sets forth the primary procedural mechanism for resolving those disputes. Among other things, section 4062 governs disputes regarding which specific medical treatments are appropriate. Section 4062 played this role in the statutory scheme before the Legislature mandated utilization review in the year 2003, and it continues to play this role now.2 Utilization review, by contrast, is not concerned with dispute resolution; rather, it governs the process by which the employer makes its initial decision whether to approve or deny the proposed medical treatment. Section 4610, subdivision (g)(3)(A), makes this point expressly. It states that if the employer, having followed the utilization review *246process, does anything short of fully approving the employee’s request for medical treatment, any resulting dispute is resolved under section 4062, same as ever.
One purpose of utilization review is to prevent disputes about medical treatment from ever arising. Before 2003, the medical treatment the employer was obligated to provide for work-related injuries was only vaguely defined as “treatment . . . that is reasonably required to cure or relieve from the effects of the injury.” (Former § 4600, as amended by Stats. 1998, ch. 440, § 2.) This indistinct standard left a lot of room for disagreement. The Legislature’s reforms of the workers’ compensation law in 2003 and 2004 much more precisely define the employer’s medical treatment obligation in terms of detailed treatment guidelines. (See §§ 4600, subd. (b), 4610, subd. (c).) Because proper application of these treatment guidelines requires medical expertise, the decision to modify, delay, or deny a treatment request must be made by a licensed physician. (§ 4610, subd. (e).) Thus, utilization review is best understood as a threshold procedure that the employer must follow before any dispute about medical treatment has arisen. It governs the employer’s evaluation of the treating doctor’s recommendation. If the employer approves the requested treatment, then there is no dispute and likewise no need to resort to dispute-resolution procedures. A dispute might arise only if the employer modifies, delays, or denies the requested treatment, in which case the employee may invoke section 4062’s dispute-resolution mechanism. (§§ 4610, subd. (g)(3)(A), 4062, subd. (a).)
Hence, section 4610’s utilization review is not to be conflated with the process of dispute resolution. Section 4062 continues to govern medical treatment disputes, as it did before the reforms. The statutory scheme does not create two separate dispute-resolution tracks for employers and for employees. Instead, it sets forth two successive stages of a single-track process: The employer first proceeds with utilization review under section 4610, and then the employee may dispute the employer’s conclusion under section 4062. (§ 4610, subd. (g)(3)(A).) The fact that the “employee (and only an employee)” (maj. opn., ante, at p. 237) initiates the dispute-resolution process set forth in section 4062 is not intended to exclude employers from that process; rather, it merely reflects the circumstance that utilization review has been interposed as a threshold step. The employer who seeks to object to a proposed medical treatment must follow the utilization review process. If that process results in a modification, delay, or denial of the requested treatment, then naturally the employee is the party that invokes the section 4062 dispute-resolution mechanism, because the employee is the aggrieved party.
*247To summarize, after the reforms enacted by the Legislature in 2003 and 2004, section 4062 remains the only process for resolving disputes regarding medical treatment (see § 4610, subd. (g)(3)(A)), and its cumbersomeness and lengthiness merely reflect the Legislature’s desire to ensure fairness to the parties.3 Section 4610’s utilization review does not supplant section 4062’s dispute-resolution process; rather, it adds a new threshold step to that process. It can only be said to supplant that process in the practical sense—that is, it might prevent some disputes from ever arising, thereby making resort to that process unnecessary.
All further statutory references are to the Labor Code.
Section 4062 remains the means for resolving medical treatment disputes, but in 2004 the Legislature changed the specifics of this dispute-resolution procedure in significant ways.
The 2004 reform streamlined the section 4062 dispute-resolution process in several ways that are not at issue here. In particular, the 2004 reform created the single-medical-examiner rule, thereby reducing the likelihood of litigation over medical questions. (§ 4062.2, subd. (c).)