Robinson, J.
¶ 1. The central question in this case is whether the workers’ compensation laws preclude an impairment rating and associated award of permanent partial disability (PPD) ben[15]*15efits to an injured worker on account of impairment associated with a condition known as Complex Regional Pain Syndrome (CRPS) where a claimant is not diagnosed with CRPS under the criteria listed in Chapter 16 of the American Medical Association Guides to the Evaluation of Permanent Impairment, Fifth Edition (AMA Guides, or Guides), but where a qualified expert confirms the existence of the condition pursuant to other legally admissible standards sufficient to meet a reasonable medical certainty. The Commissioner of the Department of Labor (DOL) and the trial court both concluded that 21 V.S.A. § 648(b) denies the Commissioner discretion to assign an impairment rating and thus award PPD benefits for impairment associated with CRPS where the CRPS diagnosis does not meet the diagnostic standards in Chapter 16 of the AMA Guides. We reverse.
I.
¶2. In 2006, in the course of his employment as a master plumber, claimant tore the rotator cuff in his right shoulder when he slipped and fell down a flight of stairs. In January 2007, claimant had surgery to repair the rotator cuff, after which he began physical therapy. His recovery was complicated by adhesive capsulitis — inflammation of the shoulder joint causing stiffness and chronic pain — as well as symptoms of CRPS. In April 2007, claimant underwent shoulder manipulation under anesthesia to treat the adhesive capsulitis; the procedure resulted in increased shoulder motion, but claimant’s CRPS symptoms persisted.
¶ 3. Dr. Robert Giering, a psychiatrist and pain management specialist, affirmed the CRPS diagnosis, relying on the diagnostic criteria from the International Association for the Study of Pain (IASP), confirmed that the condition was causally related to claimant’s work accident, and treated claimant for the CRPS.
¶ 4. Employer retained its own medical expert, Dr. Kuhrt Wieneke. Dr. Wieneke first saw claimant in March 2008. At that time, Dr. Wieneke confirmed the diagnosis of CRPS and concluded that claimant had not yet reached a medical end. Employer did not challenge the award of temporary disability and medical benefits to claimant on account of the CRPS.
¶ 5. In June 2008, Dr. Giering determined that claimant had reached an end medical result and referred claimant to Dr. Lefkoe for an impairment rating. In October 2008, Dr. Lefkoe issued a sixteen-page report in which he accepted Dr. Giering’s [16]*16CRPS diagnosis and assigned a forty-six percent whole person impairment rating calculated using the rating process for CRPS in the AMA Guides.
¶ 6. Dr. Wieneke saw claimant again in May 2009 to assess claimant’s permanent impairment on behalf of employer. Using the Guides, he concluded that claimant’s CRPS had resolved and assigned a three percent whole person rating to claimant’s shoulder injury on account of range-of-motion limitations and generalized pain. But because he concluded that claimant did not satisfy the diagnostic criteria for CRPS listed in Chapter 16 of the AMA Guides, Dr. Wieneke did not attribute any impairment for deficits or symptoms associated with CRPS.
¶ 7. After a contested hearing on the question of claimant’s impairment rating, the DOL Commissioner issued findings and conclusions. The Commissioner explained that CRPS is a condition of the sympathetic nervous system characterized by burning pain throughout the affected limb. The Commissioner described the four categories of signs and symptoms of CRPS: (1) pain disproportionate to what would be expected from the inciting injury and/or pain in response to a light touch that is not normally painful; (2) changes in skin color and/or temperature in the affected limb; (3) edema, swelling and/or sweating in the affected limb; and (4) motor changes, such as decreased range of motion and or motor dysfunction, and trophic changes involving abnormal nail and/or hair growth.
¶ 8. The Commissioner also explained that the AMA Guides and the IASP rely on similar objective signs to support a CRPS diagnosis. However, Chapter 16 of the AMA Guides requires a greater number of those signs to support a CRPS diagnosis, and calls for consideration only of observed signs, as opposed to reported symptoms. For that reason, the AMA Guides’ diagnostic criteria are more stringent than those of the IASP.1
¶ 9. The Commissioner had no doubt that under the IASP’s diagnostic criteria claimant was properly diagnosed with CRPS, but concluded that the record did not support the CRPS diagnosis under the AMA Guides’ diagnostic rubric. As a result, the [17]*17Commissioner concluded: “I am compelled to reject Dr. Lefkoe’s opinion — not because it is unpersuasive, but because under the particular circumstances of this case the statute requires it.” The Commissioner found that Dr. Lefkoe used the appropriate mechanism under the AMA Guides for rating impairment associated with CRPS, but concluded that unless CRPS is diagnosed in accordance with the criteria outlined in Chapter 16 of the AMA Guides, a claimant is not entitled to a rating for impairment associated with CRPS. Accordingly, the Commissioner assigned a three percent whole person impairment rating per Dr, Wieneke’s report.
¶ 10. Claimant appealed to the superior court which held a de novo bench trial on the question of claimant’s permanent impairment rating. In a thoughtful opinion, the court compared the competing expert medical opinions and found that Dr. Lefkoe’s evaluation was “more comprehensive and explained clearly the basis for his opinion,” while “Dr. Wieneke was less thorough and less clear when articulating how he arrived at his permanency rating, at one point contradicting himself while testifying.” The court also concluded that Dr. Lefkoe spent considerably more time evaluating claimant than Dr. Wieneke, and drafted a significantly longer and more thorough report.
¶ 11. Nonetheless, like the Commissioner, the court concluded that it was bound to reject Dr. Lefkoe’s rating for impairment associated with CRPS because 21 V.S.A. § 648(b) provides, “Any determination of the existence and degree of permanent partial impairment shall be made only in accordance with the whole person determinations as set out in the fifth edition of the [AMA Guides].” The court found that the AMA Guides Chapter 16 criteria “controls both the diagnosis of impairments and the corresponding computation of the impairment rating,” and that as a matter of law to qualify for a permanent impairment rating “a condition must be diagnosed in accordance with the AMA Guides 5th criteria.” From this, the court concluded that “as a matter of law, in order to qualify for a permanent impairment rating, a condition must be diagnosed in accordance with the AMA Guides 5th criteria.”2 Although the court rejected Dr. Lefkoe’s rating of [18]*18claimant’s impairment associated with CRPS, it did adopt Dr. Lefkoe’s findings concerning impairment associated with claimant’s loss of range of motion, and it increased claimant’s impairment rating to six percent whole person.
¶ 12. The sole question on appeal is whether 21 V.S.A. § 648(b) requires a factfinder to disallow any permanent impairment rating associated with CRPS where the diagnosis does not comport with the diagnostic standards in Chapter 16 of the AMA Guides.
II.
¶ 13. A brief review of relevant aspects of Vermont’s workers’ compensation law and the AMA Guides is helpful. Vermont’s workers’ compensation law requires employers to provide specified benefits on a no-fault basis to workers who suffer “a personal injury by accident arising out of and in the course of employment.” 21 V.S.A. § 618(a)(1). Among the benefits potentially available to an injured worker are medical benefits, id. § 640, temporary total or partial disability benefits, id. §§ 642, 646, vocational rehabilitation benefits, id. § 641, and permanent partial or permanent total disability benefits, id. §§ 644, 648.
¶ 14. The award of temporary disability benefits is based on an individual’s incapacity for work. Bishop v. Town of Barre, 140 Vt. 564, 571, 442 A.2d 50, 53 (1982). Permanent partial disability benefits are awarded based on an assessment of an individual’s “impairment,” without direct consideration of the impact of that impairment on an individual’s capacity to work. Id.; see also 21 V.S.A. § 648. Neither the statute nor the DOL’s rules define “impairment,” but the Vermont Legislature has directed that permanent impairment be assessed using the AMA Guides: “Any determination of the existence and degree of permanent partial [19]*19impairment shall be made only in accordance with the whole person determinations as set out in the fifth edition of the American Medical Association Guides to the Evaluation of Permanent Impairment.” 21 V.S.A. § 648(b).3 The statute further provides that the Commissioner shall adopt a supplementary schedule for rating injuries not rated by the operative guidelines. The DOL, by rule, has provided that impairments for injuries not rated by the AMA Guides “shall be in proportion to the compensation paid for similar injuries rated by the Guides.” Workers’ Compensation Rules § 11.2500, 3 Code of Vt. Rules 24 010 003-8, available at http://www.lexisnexis.com/hottopics/codeofvtrules.
¶ 15. Significantly, although the concept of a “diagnosis” may be helpful in describing or labeling an injury, nothing in Vermont’s workers’ compensation scheme predicates a claimant’s entitlement to benefits on the existence of a particular diagnosis. The threshold trigger for benefits is an “injury” — defined in the case of physical injuries as “any harmful . . . change in the body.” Workers’ Compensation Rules § 2.1240, 3 Code of Vt. Rules 24 010 003-2, available at http://www.lexisnexis.com/hottopics/codeof vtrules. The touchstone for PPD benefits is “impairment” as measured pursuant to the AMA Guides or determined by the Commissioner if the Guides do not rate a particular type of injury. The Guides define impairment as “a loss, loss of use, or derangement of any body part, organ system, or organ function.” AMA Guides at 2 (quotations omitted).
¶ 16. The AMA Guides to the Evaluation of Permanent Impairment were developed “in response to a public need for a standardized, objective approach to evaluating medical impairments.” Id. at 1. The AMA Guides are broken into chapters, each focusing on impairment rating methods for a different organ system or body part, and each authored by experts from the relevant specialties. Id.4 The impairment rating methodologies [20]*20vary considerably from chapter to chapter, depending on the body parts or organ systems involved. Some impairments can be rated pursuant to multiple chapters. Id. at 19. Although the diagnosis associated with an injury may point the examiner to the applicable impairment rating methodology or methodologies in a given case, “diagnosis” per se is not intrinsic to the identification or measurement of many impairments in the AMA Guides. See, e.g., id. at 450-79 (rating impairments in range of motion of various joints without reference to diagnosis of condition causing limitation in range of motion); id. at 118-20 (rating upper digestive tract impairment with reference to symptoms and signs of upper digestive tract disease or anatomic loss or alteration without regard to specific underlying diagnosis). But see id. at 231 (providing that impairment rating for diabetes mellitus varies depending on whether diabetes is Type 1 or Type 2).
¶ 17. The Guides provide two distinct methods for rating CRPS in an upper extremity — one in Chapter 13 relating to the central and peripheral nervous system, id. at 343-44, and another at section 16.5e of Chapter 16 relating to the upper extremities, id. at 482-83, 495-97. At issue in this case is the approach laid out in Chapter 16.5 With respect to the diagnosis of CRPS, that chapter identifies eleven objective diagnostic criteria for CRPS and provides that the presence of eight or more of those factors supports a CRPS diagnosis. Id. at 496, Table 16-16. For the purposes of assigning an impairment rating, the chapter further distinguishes between CRPS I, also known as reflex sympathetic dystrophy (RSD), and CRPS II, also known as causalgia. Id. at 495-96. The CRPS I rating methodology applies when neither the initiating causative factor nor the symptoms involve a specific peripheral nerve or structure, and the CRPS II methodology applies when a specific sensory or mixed nerve structure is involved. Although Chapter 16 lists criteria for identifying CRPS cases, the CRPS diagnosis itself is not a variable in the rating algorithm. Instead, [21]*21the loss of motion of the involved joints and the sensory deficits and pain associated with the condition are the determinants of the actual impairment rating for CRPS I. Id. at 496.
III.
¶ 18. With that in mind, we turn to the statute. We are mindful of our traditional deference to the Commissioner’s interpretation of workers’ compensation statutes, calling for affirmation of the Commissioner’s construction absent a compelling indication of error. Wood v. Fletcher Allen Health Care, 169 Vt. 419, 422, 739 A.2d 1201, 1204 (1999). We will not, however, “affirm an interpretation that is unjust or unreasonable,” Clodgo v. Rentavision, Inc., 166 Vt. 548, 550, 701 A.2d 1044, 1045 (1997), or one that undermines the regulatory purpose of the statute. See In re Williston Inn Grp., 2008 VT 47, ¶ 16, 183 Vt. 621, 949 A.2d 1073 (mem.).
¶ 19. In addition, because the workers’ compensation system is remedial, we have an obligation to “construe the Workers’ Compensation Act liberally so that injured employees receive benefits ‘unless the law is clear to the contrary.’ ” Butler v. Huttig Bldg. Products, 2003 VT 48, ¶ 12, 175 Vt. 323, 830 A.2d 44 (quotation omitted).
¶ 20. Our primary objective in interpreting statutes is to give effect to the intent of the Legislature. To determine that intent, we “must examine and consider fairly, not just isolated sentences or phrases, but the whole and every part of the statute, . . . together with other statutes standing in pari materia with it, as parts of a unified statutory system.” State v. Jarvis, 146 Vt. 636, 637-38, 509 A.2d 1005, 1006 (1986) (quotation omitted).
¶ 21. The language in question is clear: the Legislature has directed that the AMA Guides are determinative with respect to “[a]ny determination of the existence and degree of permanent partial impairment” associated with an injury. 21 V.S.A. § 648(b) (emphasis added). PPD benefits are available for permanent impairments associated with an injury. Id.. § 648(a). Nowhere does the statute state that the AMA Guides provide the exclusive mechanism for determining the existence of, or diagnosis associated with, a compensable injury. Rather, the statute declares that the rating of an impairment is to be conducted pursuant to the [22]*22AMA Guides. See Payne v. US Airways, Inc., 2009 VT 90, ¶ 9, 186 Vt. 458, 987 A.2d 944 (in discerning legislative intent, “we start with the language of the statute and read it according to its plain and ordinary meaning”).
¶ 22. To the extent that Chapter 16 of the AMA Guides purports to establish fixed criteria for diagnosing CRPS, as opposed to a method for rating the impairment associated with that condition, § 648(b) does not imbue those criteria with the force of law. The Guides may be used as evidence to support expert testimony concerning the presence of CRPS, and a factfinder may choose to rely upon the criteria listed in Chapter 16 of the Guides in determining if a claimant has an injury and whether that injury is appropriately labeled “CRPS.” But the Guides do not necessarily contain the exclusive authoritative standard for diagnosing the condition. In the face of competing opinions regarding diagnosis, a factfinder must exercise reasoned judgment in weighing the competing expert opinions. See Houle v. Ethan Allen, Inc., 2011 VT 62, ¶ 9, 190 Vt. 536, 24 A.3d 586 (mem.) (listing factors considered by Commissioner in weighing competing expert opinions).
¶23. The dissent keys in on the statute’s reference to a “determination of the existence and degree” of impairment, and argues that the reference to the “existence” of an impairment suggests that § 648(b) therefore incorporates the AMA Guides’ criteria for diagnosing conditions. Post, ¶¶ 56-57. The implication is that no impairment exists — that is, no “loss, loss of use, or derangement of any body part, organ system, or organ function” can be found, AMA Guides at 2 — unless claimant is diagnosed with CRPS in conformity with the criteria set forth in Table 16-16 of the AMA Guides. This view conflates injury, impairment, and diagnosis. “Diagnosis” of CRPS is not the same as “the existence of an impairment,” and the reference in § 648(b) to the “existence” of an impairment does not, as implied by the dissent’s analysis, broaden that provision’s focus on impairment to include diagnosis, injury, or any other concept; it just reflects an acknowledgment that in some cases an injury may not give rise to any associated permanent impairment.
¶ 24. The view that § 648(b) identifies the AMA Guides as the basis for rating impairments, but leaves the determination of the existence of an injury and, where relevant, the diagnosis associ[23]*23ated with that injury to the factfinder to assess based on all the evidence, is congruent with the Commissioner’s own past analysis. The Commissioner previously concluded in the context of benefits other than permanency that the AMA Guides’ diagnostic criteria for CRPS are not determinative. Workers’ Compensation Board: Chartier v. Cent. Vt. Med. Ctr., No. 22-09WC (June 26, 2009), http://www.labor.vt.gOv/portals/0/WC/ChartierDecision.pdf. In that case, the Commissioner considered whether a claimant suffered from reflex sympathetic dystrophy (RSD) as a result of a work-related injury. The claimant’s treating physician diagnosed the claimant based on criteria outlined in a medical text, and several other treating providers concurred in the diagnosis; the defendant’s expert concluded that the claimant did not suffer from RSD on the basis of the criteria outlined in the AMA Guides at Table 16-16. The Commissioner rejected the testimony of the defendant’s expert. In that case, the Commissioner was not construing 21 V.S.A. § 648(b), the provision concerning permanent impairment benefits at issue here. However, the Commissioner’s findings concerning the role of the AMA Guides are instructive insofar as they reflect the Commissioner’s understanding of the distinction between diagnosing a condition and rating the associated impairment: “The AMA Guides are statutorily designated as the standard to use for rating the extent of an injured worker’s permanent impairment. Treating doctors do not necessarily refer to the AMA Guides to diagnose patients, however.” Chartier, at 5.
¶ 25. Our interpretation also best jibes with the broader goals of the workers’ compensation laws. See Delta Psi Fraternity v. City of Burlington, 2008 VT 129, ¶ 7, 185 Vt. 129, 969 A.2d 54 (legislative intent is derived from consideration of “entire enactment, its reason, purpose and consequences” in addition to particular statutory language) (quotation omitted). The Legislature has made it clear that its goal is not to ensure compliance with the AMA Guides as an end in itself; rather, the Guides are a tool to promote the Legislature’s goal of ensuring that individuals who suffer permanent impairment as a result of work-related injuries receive appropriate PPD benefits. Section 648 in its entirety reflects a clear statutory intent that no bona fide impairment should go uncompensated simply because the AMA Guides fail to provide a method for assigning a rating to a particular condition. Instead, the statute specifically authorizes the Commissioner to develop methods for rating impairments not covered by the [24]*24Guides, 21 V.S.A. § 648(b), and the Commissioner has adopted a rule to ensure that impairments not expressly included in the AMA Guides are rated and lead to compensation, Workers’ Compensation Rules § 11.2500.6 Accordingly, pursuant to the statutory scheme, individuals suffering from impairments not specifically described or listed in the AMA Guides nonetheless may be entitled to an impairment rating and associated PPD benefits if supported by sufficient expert testimony.
¶ 26. Applied to the facts of this case, the dissent’s construction of the statute is at odds with this legislative goal, as well as the remedial nature of the workers’ compensation scheme. Montgomery, 142 Vt. at 463, 457 A.2d at 646. Everyone agrees that claimant developed CRPS as a result of his work injury. Even Dr. Wieneke affirmed that diagnosis, although he concluded that the syndrome had resolved by the time claimant reached a medical end. But see Workers’ Compensation Board: H.K. v. Woodridge Nursing Home, No. 01-07WC (Jan. 16, 2007), http://159.105.83.163/portals/0/WC/U50905Kennett.pdf (rejecting opinion of expert who opined that claimant did not meet criteria for RSD diagnosis under AMA Guides, noting that “RSD is not a static state, . . . symptoms can ebb and flow,” and finding that claimant was likely not highly symptomatic at time that those who opined against diagnosis examined her). No one has suggested that the failure of claimant’s condition to satisfy the diagnostic criteria outlined in Table 16-16 of the AMA Guides defeated his entitlement to medical benefits, temporary disability, or vocational rehabilitation benefits associated with his injury. In the dissent’s view, claimant had a work injury — diagnosed by his providers as CRPS and compensable for the purposes of temporary disability benefits, medical benefits, [25]*25and vocational rehabilitation benefits. But then, as a matter of law, claimant did not have CRPS, and therefore by definition was ineligible for evaluation of any permanent impairment associated with that condition once he reached a medical end point, regardless of any evidence of functional limitations associated with the CRPS pursuant to the AMA Guides’ rating system. That would be an incongruous state of affairs given the expressed legislative goal of compensating impairments — not diagnoses — resulting from work injuries.
IV.
¶ 27. The dissent describes the ongoing controversy within the medical community about the best way to diagnose CRPS and argues that the drafters of Chapter 16 of the AMA Guides do not believe that a claimant can be appropriately diagnosed with CRPS unless the claimant’s constellation of subjective and objective findings meets the diagnostic criteria set forth in Chapter 16. Post, ¶ 41.7 The question here is not what the drafters of Chapter 16 believe to be the essential components of a CRPS diagnosis; the question is whether, as a matter of law, the statute prevents the Commissioner from assigning an impairment rating under [26]*26Chapter 16 of the AMA Guides to an individual who has been diagnosed with CRPS by a competent physician using medically-accepted criteria and on the basis of objective findings.8
¶ 28. The diagnosis of CRPS itself is not intrinsic to the actual impairment rating process for CRPS. Given a CRPS diagnosis, the AMA Guides provide a coherent set of criteria for evaluating the impairment associated with that condition that do not include the diagnosis itself. The. Commissioner specifically found that after diagnosing claimant’s condition pursuant to criteria endorsed by a different medical association, Dr. Lefkoe “followed the procedure mandated by the AMA Guides for determining the appropriate impairment rating in cases involving the type of CRPS from which claimant presumably suffers.” The trial court likewise found that, setting aside its conclusion that the claimant’s impairment was not subject to a rating pursuant to Chapter 16 because his condition did not meet that chapter’s diagnostic criteria, Dr. Lefkoe’s ultimate permanency rating was correctly computed using Chapter 16 of the AMA Guides.
¶ 29. Moreover, Chapter 16 is not the only chapter in the AMA Guides pursuant to which CRPS can be rated. Chapter 18, relating to the central and peripheral nervous system, also offers a methodology for rating impairments associated with CRPS/RSD in an upper extremity. See AMA Guides at 343-44. That section describes many of the same indicia of CRPS that are listed in Chapter 16. Id. at 343, 496. However, in contrast to Chapter 16, nothing in Chapter 13 suggests that a specific minimum number of findings is a prerequisite to a CRPS diagnosis or to a rating for the impairment .associated with that condition. The Guides themselves thus provide a different framework for diagnosing CRPS.
¶ 30. The dissent’s approach to rating impairment associated with CRPS is also inconsistent with the commitment reflected in both the workers’ compensation statute and the AMA Guides themselves to ensure conditions that are not specifically listed in the AMA Guides are nonetheless ratable. The Guides afford latitude to examiners to exercise discretion in choosing the best [27]*27rating methodology for a given condition, AMA Guides at 19, and in selecting a specific rating within the sometimes wide ranges dictated by the Guides, id. at 20 passim. And, significantly, the Guides suggest that in situations where the Guides do not provide impairment ratings, “physicians usé clinical judgment, comparing measurable impairment resulting from the unlisted condition to measurable impairment resulting from similar conditions with similar impairment of function in performing activities of daily living.” Id. at 11.
¶ 31. In other words, even if a claimant’s condition does not fit within any ratable impairments listed in the AMA Guides, an evaluator may use a closely matching rating methodology in the AMA Guides to determine an impairment rating. See supra, ¶ 25 & n.6 (statute directs Commissioner to develop methods for rating impairments not covered by Guides, and Commissioner has accepted ratings from chapters of Guides designed for rating nonpsychological injuries in awarding PPD benefits for psychological injuries not otherwise rated in Guides); see also AMA Guides at 11 (recognizing that “[ejlinical judgment, combining both the ‘art’ and ‘science’ of medicine, constitutes the essence of medical practice”); id. at 18 (acknowledging that impairment evaluation process “requires considerable medical expertise and judgment”); id. at 19 (expressly authorizing evaluators to deviate from specific guidance of Guides in assigning impairment ratings if, in their considered clinical judgment, methodology in Guides does not produce fitting rating in particular case).
¶ 32. Given that both the statute and the Guides expressly allow evaluators to rate an impairment using the rating method set forth in a specific section of the Guides even if an individual’s condition (or diagnosis) is not the condition (or diagnosis) for which that section is specifically designed, and given the Guides’ own recognition of the importance of an evaluator’s clinical judgment in the rating process, it would be odd to say that the Commissioner does not have the discretion to accept a rating under section 16.5e of the AMA Guides for an individual with an established loss of function (or impairment) and a persuasive diagnosis of CRPS based on objective findings and medically-accepted standards when the rating physician concludes that section 16.5e provides the most appropriate method for rating the impairment.
[28]*28¶ 33. In Tokico (USA), Inc. v. Kelly — a case on all fours with this case — the Kentucky Supreme Court provided persuasive analysis on the issue before us. 281 S.W.3d 771 (Ky. 2009). In that case, the Kentucky Supreme Court affirmed an impairment rating for CRPS I even' though the physician who gave the rating concluded that the claimant exhibited only seven of the eleven diagnostic criteria in the AMA Guides. Id. at 773. The Guides require that “at least eight of the [eleven] findings must be present concurrently for a diagnosis of CRPS,” but the physician concluded nonetheless that claimant had “an absolutely classic case” of CRPS I and that “he had no doubt she suffered from ‘some definite form’ of the condition.” Id. Using his clinical judgment, the physician concluded that to rate the claimant’s impairment using another method would be less accurate than rating for CRPS I based on seven rather than eight objective criteria. Id. at 774. Reviewing the rating, the court cited the AMA Guides’ acknowledgments that some medical syndromes are poorly understood, and that physicians must use clinical judgment when assigning impairment ratings. Id. The court concluded:
Diagnosing what causes impairment and assigning an impairment rating are different matters. Diagnostic criteria stated in the Guides clearly have relevance when judging the credibility of a diagnosis, but [Kentucky’s statute] does not require a diagnosis to conform to criteria listed in the Guides.
Id. at 774-75. Like the Vermont statute, the Kentucky statute at issue required that permanent impairment be assessed pursuant to. the AMA Guides. See Ky. Rev. Stat. § 342.0011(35) (“ ‘Permanent impairment rating’ means percentage of whole body impairment caused by the injury or occupational disease as determined by the ‘Guides to the Evaluation of Permanent Impairment.’ ”).9
[29]*29¶ 34. The dissent argues that the rating process for CRPS in Chapter 16 of the Guides expressly incorporates the more stringent diagnostic criteria in order to lend objectivity to the impairment rating. We agree that in evaluating impairment the Commissioner must consider whether the alleged CRPS condition is supported by objective findings, but we note that this is not a case in which the CRPS diagnosis is unsupported by objective findings. Drs. Giering and Lefkoe identified a host of objective findings, incorporated into the IASP diagnostic criteria upon which they relied, to support their conclusion. For example, Dr. Giering explained that the color and temperature changes' in claimant’s affected limb — both factors included in the AMA Guides as factors supporting a CRPS diagnosis — were signs of vasomotor changes that are characteristic of a classic presentation of CRPS. The roadblock to a finding of permanent impairment in this case was the specific minimum number of findings to support the CRPS diagnosis pursuant to Table 16-16 of the Guides. Although parties are free to argue that the Guides’ diagnostic criteria are more objective than those of the IASP, and that the Guides are therefore a better tool for determining whether a claimant suffers from CRPS I and is suitable for an impairment rating associated with that condition, it is not consistent with § 648(b) to treat the Guides’ method for diagnosing CRPS I as the only legally acceptable method.
¶ 35. We emphasize the limited scope of our holding. We do not hold as a matter of law that claimant in this case is entitled to PPD benefits on account of the aspect of his injury diagnosed as CRPS. On remand, the factfinder is free to conclude that claimant’s impairment should not be rated pursuant to section 16.5e of Chapter 16. To the extent that Dr. Wieneke’s opinion suggests that claimant has no ratable impairment associated with CRPS, the Commissioner may even conclude that claimant does [30]*30not have an impairment from CRPS at all. However, by deferring to the AMA Guides with respect to the methodology for rating an impairment, the Vermont Legislature has not purported to remove from the Commissioner the discretion to consider conflicting competent expert opinions concerning the presence of an impairment. Houle, 2011 VT 62, ¶¶ 13-15 (deferring to Commissioner’s factfinding concerning conflicting expert testimony).
¶ 36. For the above reasons, we conclude that the trial court and the Commissioner erred in concluding that 21 V.S.A. § 648(b) and the AMA Guides precluded them, as a matter of law, from considering any evidence of claimant’s impairment associated with CRPS. We remand to the trial court for reconsideration of claimant’s permanent impairment rating in light of the above analysis.
Reversed and remanded.