Opinion by
T1 In this workers' compensation action, claimant, Ricardo Meza, seeks review of a final order of the Industrial Claim Appeals Office (Panel) affirming an administrative law judge's order awarding claimant permanent partial disability (PPD) benefits based on an impairment rating of ten percent of the lower right extremity given claimant after a division-sponsored independent medical examination (DIME).
T2 Claimant argues that the ALJ: (1) lacked jurisdiction because employer did not appeal from an earlier eighteen-month DIME; (2) failed to give appropriate presumptive weight to the eighteen-month DIME, and (8) rendered an impairment decision not supported by substantial evidence. We address and reject each argument in turn, concluding that an eighteen-month DIME carries presumptive weight only with respect to maximum medical improvement (MMI), but not as to impairment; and because the ALJ correctly determined that the eighteen-month DIME's impairment rating was consequently not binding, substantial evidence supported the ALJ's PPD determination and therefore affirm the Panel's order.
I. Background
T3 Claimant sustained an admitted, com-pensable injury in 2004 when a cow bone fell on his right foot. On November 26, 2004, his authorized treating physician (ATP) placed him at MMI with no impairment and released him to work without restrictions. Plaintiff continued to experience pain, however, including the development of low back pain about four years after his initial injury.
14 Based on these pain complaints, employer, Swift Foods Company, and its insurer, Zurich American Insurance Company (collectively employer), agreed to reopen the claim in 2008. Upon reopening, claimant was treated by a new ATP who suspected that claimant had developed complex regional pain syndrome (CRPS) and that his low back pain was related to the foot injury. A physi
T5 Because the ATP had not placed claimant at MMI within eighteen months of commencing treatment, employer requested a DIME, as authorized by section 8-42-107(8)(b)(II). The DIME physician performed the eighteen-month DIME in January 2010, and placed claimant at MMI effective the date of the exam. In addition, the eighteen-month DIME physician issued a rating of claimant's impairment at ten percent of the whole person for CRPS and eleven percent for claimant's spine, giving claimant a combined impairment rating of twenty percent of the whole person.
16 Employer filed a final admission of liability (FAL) based upon the eighteen-month DIME physician's MMI and impairment ratings. However, claimant moved to strike the FAL, arguing that under section 8-42-107(8)(b)(II) and (8)(c), C.R.S.2012, a physician performing an eighteen-month DIME is limited to determining MMI and may not properly give an impairment rating. Under section 8-42-107.5, C.R.S.2012, a claimant with an impairment rating of twenty-five percent or less of the whole person, such as the rating given claimant by the eighteen-month DIME physician, is limited to receiving no more than $75,000 in partial and permanent disability. Claimant's counsel stated at the hearing before the ALJ that he challenged the eighteen-month DIME physician's twenty percent whole person impairment rating because claimant was "trying to get over the cap." Claimant therefore requested that he be sent back to his ATP for an impairment rating under section 842-107(8)(c).
T7 An ALJ agreed that the eighteen-month DIME physician had overstepped his statutory authority, struck the FAL, and ordered claimant to see his ATP for a permanent impairment evaluation. The ALJ specifically ordered:
Claimant shall return to his [ATP] for a permanent impairment evaluation. Following that determination by the [ATP, employer] shall, as provided by statute, either file a [FAL] reflecting the MMI determination of [the eighteen-month DIME physician] and the impairment rating of the [ATP], or may request a [DIME] regarding either issue. If [employer] file[s] a [FAL], [ellaimant may then request a DIME by following statutory procedures.
T8 Claimant returned to his ATP, who disagreed with the eighteen-month DIME physician's conclusion that claimant had reached MMI. Nonetheless, he rated claimant's impairment, giving claimant a higher impairment rating than the eighteen-month DIME physician had: eighteen percent for his spinal injuries, ten percent for CRPS, and four percent for the lower extremity, resulting in a total impairment rating of twenty-seven percent of the whole person.
T9 Pursuant to the ALJ's order and seetion 8-42-107(8)(c), employer requested a second DIME to review the ATP's impairment rating. The parties selected a different physician to perform this second DIME. The second DIME physician agreed with the eighteen-month DIME physician that claimant had reached MMI in January 2010, but provided different impairment ratings. In her written report, the second DIME physician rated claimant's impairment as eighteen percent of the whole person, incorporating impairment ratings for his lower extremity injury, spine, and CRPS. However, in her deposition, the second DIME physician testified that the CRPS rating in the written report was "incorrect," and opined that claimant's impairment relating to his work injury was limited to his lower extremity. She therefore testified that his corrected impairment rating was ten percent of the lower extremity or four percent of the whole person.
10 At the hearing, claimant objected to the second DIME physician's opinions. Contrary to what he had stated in his motion to strike the FAL, he argued that the second DIME physician was bound by the impairment ratings and causality findings made by
T11 The ALJ disagreed, concluding that when claimant moved to strike the FAL he waived his opportunity to rely on any presumptive weight that might otherwise have been given to the eighteen-month DIME's impairment rating. Finding the testimonial opinions of the second DIME physician persuasive and credible, the ALJ also concluded that claimant had not overcome her opinions by clear and convincing evidence. The ALJ therefore awarded claimant PPD benefits based on an impairment rating of ten percent of the lower extremity, but found claimant's spine injury and CRPS unrelated and therefore awarded no benefits for those two conditions. As a result, the ALJ also denied and dismissed claimant's request "for maintenance medical care ... treatment for his lower back and ... CRPS-like complaints."
€ 12 On claimant's petition for review, the Panel held that employer's FAL had properly been stricken. It further held that when an eighteen-month DIME is conducted, MMI and impairment are "bifurcated" such that the eighteen-month DIME physician's opinion is presumptive only with respect to MMI; a later DIME, conducted after an ATP has issued an impairment rating, is presumptive regarding impairment. Thus, although the Panel did not adopt the ALJ's conclusion that claimant had waived his argument regarding the weight to be given to the eighteen-month DIME, the Panel nonetheless affirmed the ALJ's decision.
II. Analysis
113 On appeal, claimant seeks to have "[the second DIME physician]'s impairment ratings on CRPS and the lower back condition" added to the ALJ's PPD benefits award based on a ten percent lower extremity impairment rating. He argues that he is entitled to the higher impairment rating because (1) the ALJ was bound by the eighteen-month DIME physician's opinions and therefore lacked jurisdiction to rule on the relatedness of his alleged CRPS and low back conditions, and (2) the ALJ improperly assigned him the burden of overcoming the second DIME physician's opinion. In addition, he also seeks an award for maintenance medical care, arguing that the ALJ erred by denying him these benefits. We reject these arguments.
A. Jurisdiction
€ 14 Claimant first contends that the ALJ was jurisdictionally barred from finding that claimant's CRPS condition, if any, and his low back complaints were unrelated to the May 2004 work-related injury. Contrary to his motion to strike the FAL, claimant argues that the determination of the eighteen-month DIME physician-who opined that claimant's low back pain and CRPS impairments were caused by claimant's 2004 work infury-was binding on the ALJ because neither party had requested a hearing to challenge his opinions. We disagree.
1. Scope of Eighteen-Month DIME
915 In general, "a DIME physician's opinions concerning MMI and permanent medical impairment are given presumptive effect," and therefore must be overcome by clear and convincing evidence. Leprino Foods Co. v. Indus. Claim Appeals Office,
116 However, the Panel concluded that these general rules do not govern when an eighteen-month DIME is requested under section 8-42-107(8)(b)(II). Rather, the Panel determined that an eighteen-month DIME physician's opinions regarding impairment are not presumptively binding because the statutory subsection providing for an eighteen-month DIME neither mentions nor ad-
T17 As with all statutory construction, if the language of a provision of the Workers' Compensation Act (Act) is clear, "we interpret the statute according to its plain and ordinary meaning," Davison v. Indus. Claim Appeals Office,
1 18 While we are not bound by the Panel's interpretation or its earlier decisions, Olivas, Soto v. Indus. Claim Appeals Office,
119 Because section 8-42-107(8)(b)(II) makes no mention of impairment ratings, we conclude that the Panel's interpretation that an eighteen-month DIME physician's determination is presumptively binding only as to MMI is a reasonable and consistent application of the clear language of the statute.
120 The division's holding in Leprino Foods, on which claimant relies, does not persuade us to the contrary. Leprino Foods concerned a DIME conducted after the claimant's ATP had placed her at MMI and issued an impairment rating. Thus, the Lep-rimno Foods DIME proceeded under section 8-42-107(8)(c), which authorizes a DIME physician to determine both MMI and impairment.
{21 In contrast, the statute authorizing the eighteen-month DIME refers only to determination of MMI. See § 8-42-107(8)(b)(II). The finding of MMI is entitled to presumptive weight that may be overcome "only by clear and convincing evidence." § 8-42-107(8)(b)(IIT), C.R.S8.2012. The eighteen-month DIME physician is not statutorily authorized to address impairment. And we may not read such a provision into the Act. See Kraus v. Arteraft Sign Co.,
122 We therefore conclude that when an eighteen-month DIME is issued under seetion 8-42-107(8)(b)(II), the physician's determination carries presumptive, binding weight concerning only MML
2. No Jurisdictional Bar
123 Because the eighteen-month DIME physician's impairment ratings carried no presumptive effect, the causation findings as
124 To the contrary, the impairment issues, and consequently the related causation issues, addressed by the eighteen-month DIME were not ripe for hearing until the ATP had opined on claimant's impairment and the second DIME physician had issued her impairment ratings. See § 8-42-107(8)(c) ("A hearing on this matter shall not take place until the finding of the independent medical examiner has been filed with the division."); Delaney v. Indus. Claim Appeals Office, 80 P.8d 691, 694 (Colo.App.2000) ("[Rlesolution of the permanent impairment issue should be deferred until after the DIME report has been filed.").
1 25 Accordingly, the ALJ was not jurisdic-tionally barred from considering the causation of claimant's impairment.
126 Nor are we persuaded, as claimant appears to suggest, that the eighteen-month DIME physician's discussion of claimant's CRPS-like condition and low back complaints related exclusively to his MMI findings and thus was entitled to presumptive validity. In our view, the cighteen-month DIME physician's conclusions that claimant's CRPS and low back conditions are compensable are integral to that physician's stricken impairment rating.
127 In his report, the eighteen-month DIME physician observed that claimant had "probable [CRPS] ... at [MMI] but with permanent impairment." He also noted that because of "the equivocal nature of the [CRPS] diagnosis in this case" and "the possibility of symptom magnification and see-ondary gain," the impairment rating for CRPS was ten percent of the whole person. With respect to claimant's complaints of low back pain, the eighteen-month DIME physician observed these were "probably secondary to antalgic gait" and concluded claimant's spine impairment was eleven percent. Thus, his observations that claimant's possible CRPS and low back pain were related to the 2004 work injury were made largely in conjunction with the impairment ratings he issued, rather than with his MMI determination. Because these opinions related to the impairment ratings the eighteen-month DIME physician assigned to claimant's CRPS and low back pain, they carried no presumptive weight and did not become final and beyond challenge.
3. Binding Effect of Causation Determination
128 As a corollary, claimant now appears to also argue that even if the eighteen-month DIME physician's impairment ratings are not binding, his causation findings related to claimant's CRPS and low back injury, separate and apart from his MMI and impairment findings, should be binding. However, a DIME physician's opinion regarding the causation or compensability of a claim never carries any presumptive weight. See Leprino Foods,
4. Presumption of Validity of Second DIME Physician's Opinions
129 Claimant next contends that the ALJ "did not enforce the presumption of validity" associated with the eighteen-month DIME physician's causation determinations. As we understand claimant's contention, this argument, too, is premised on the incorrect notion that the eighteen-month DIME physician's causation opinions were related to only MML. But, as noted above, MMI and impairment are distinct under the Act, and causation may relate to either or both.
830 We have already determined that to the extent the eighteen-month DIME physi
131 Moreover, it was for the ALJ to determine if the impairment opinions expressed by the second DIME physician, including the causes of claimant's impairment, had been overcome by clear and convincing evidence. See Mosley v. Indus. Claim Appeals Office,
1382 Here, although the ATP's and eighteen-month DIME physician's opinions concerning causation and impairment were contrary to those of the second DIME physician, a physician retained by employer agreed with the second DIME physician that claimant's low back pain and CRPS, if any, were unrelated to his work injury. Thus, the second DIME physician's opinions are corroborated by other evidence in the record. The ALJ found the opinions of this retained physician and the second DIME physician credible and persuasive. Conversely, the ALJ found the opinions and testimony of claimant's ATP to be less persuasive and less reliable. In addition, relying on the observations of employer's IME physician, the ALJ found claimant's pain complaints unreliable.
33 Claimant's belief in the validity of his ATP's conclusions notwithstanding, the ALJ was entitled to rely on the testimony of the second DIME physician and other medical experts and to weigh the credibility of the evidence. -It is solely within the ALJ's discretionary province to weigh the evidence and determine the credibility of expert witnesses. See Metro Moving Storage Co. v. Gussert, 9
134 Given that substantial evidence supports the ALJ's determination that claimant failed to overcome the second DIME physician's impairment and causation determinations by clear and convincing evidence, we perceive no basis for setting aside the Panel's ruling upholding the ALJ's PPD award.
5. Waiver and Collateral Estoppel
{ 35 Because we have determined that the impairment ratings issued by the eighteen-month DIME physician carried no presumptive weight and were not jurisdictionally binding, we need not and do not address whether claimant waived his jurisdictional argument at the hearing or whether collateral estoppel applied.
B. Assessment of Burden of Proof
36 Claimant next contends that the ALJ improperly assigned him the burden of overcoming the second DIME physician's opinions by clear and convincing evidence. As
137 Claimant's contention presupposes that a DIME physician's written report must be given more weight than opinions orally expressed under oath. He offers no authority for this supposition, and we know of none. As noted by employer, the second DIME physician's report was unclear and ambiguous in addressing CRPS. Her testimony was elicited to shed light on her views. To the extent her testimony conflicted with her written report, it was within the ALJ's sound discretion to resolve the conflict. See Blue Mesa Forest v. Lopes,
C. Maintenance Medical Benefits
138 Lastly, claimant seeks an award of maintenance medical benefits for his lower spine complaints and CRPS-like condition. However, as the Panel and employer point out, claimant has offered little, if any, analysis supporting his contention that he is entitled to these benefits. He states only that if "this Court reverses the ALJ's causation determinations, then it should also reverse the ALJ's denial of maintenance care benefits." We have concluded, however, that the Panel properly affirmed the ALJ's causation determinations. Given the dearth of legal grounds offered to set aside the ALJ's denial of maintenance benefits beyond the arguments already discussed, we decline to address maintenance benefits further. See Mauldin v. Lowery,
T 39 The order is affirmed.