Affirmed by published opinion. Judge MURNAGHAN wrote the opinion, in which Judge NIEMEYER and Senior Judge HARVEY joined.
OPINION
Appellant William Lane, a mine worker, filed a claim for black lung, benefits pursuant to the provisions of the Black Lung Benefits Act (the “Act”), 30 U.S.C.A. §§ 901-45 (West 1986 & Supp.1996). An administrative law judge (“ALJ”) disallowed the claim on the ground that, although Lane had pneumoconi-osis, the disease did not totally disable him *169 from working. The Benefits Review Board (“BRB”) affirmed the decision. Because we find that substantial evidence supports- the ALJ’s decision to deny benefits, we also affirm.
I.
In 1973, Lane’s employer, Union Carbide Corporation (“Union Carbide”), removed Lane from working at the face of the mine because the bad dust conditions aggravated his disease. Union Carbide reclassified Lane as a general inside laborer, and he primarily worked as a belt mechanic. He ceased working in December 1983 when Union Carbide laid him off.
Lane filed a claim for benefits under the Act on March 26, 1984. In order to receive benefits under the Act, the applicable regulation provides that the miner’s pneumoconio-sis must totally disable him from working. See 20 C.F.R. § 718.204 (1996). Beginning in 1974, various doctors examined Lane and issued conflicting reports as to whether Lane’s pneumoconiosis totally disabled him from working as an inside laborer.
On April 25, 1974, Dr. D.L. Rasmussen examined Lane and administered pulmonary function studies and arterial blood gas studies that tested Lane both at rest and after exercise. Dr. Rasmussen found that Lane’s pulmonary function and resting arterial blood gas studies produced normal results, but the exercise arterial blood gas study revealed a significant impairment. Dr. Rasmussen concluded that Lane had an overall seventy-five percent loss of functional capacity and that he would be incapable of performing steady work beyond sedentary work levels.
On September 5,1980, Dr. W. Olson examined Lane for the Department of Labor. Dr. Olson performed pulmonary function studies and resting and exercise arterial blood gas studies. Although he diagnosed pneumoconi-osis, he found that the results of all of the studies were normal.
On May 11, 1984, Dr. Rasmussen examined Lane a second time on behalf of the Department of Labor. Dr. Rasmussen conducted pulmonary function studies and resting and exercise arterial blood gas studies. He diagnosed pneumoconiosis, and he again found that the pulmonary function and resting arterial blood gas studies yielded “normal” results, but he reported- that the exercise arterial blood gas study revealed a marked impairment in Lane’s respiratory functional capacity. Dr. Rasmussen concluded that Lane was totally disabled as a result of his pneumoconiosis.
Lane’s counsel asked Dr. Dominic J. Gazi-ano to validate the arterial blood gas studies that Dr. Rasmussen had administered. On November 17, 1984, Dr. Gaziano reported that Dr. Rasmussen’s studies were technically acceptable.
Dr. George L. Zaldivar examined Lane on September 18, 1985. He conducted pulmonary function and resting arterial blood gas studies, but he did not perform an exercise arterial blood gas study because of Lane’s elevated blood pressure. Dr. Zaldivar diagnosed early pneumoconiosis, but he concluded that the results of all the tests were entirely normal and that no pulmonary impairment resulted from the pneumoconiosis. Dr. Zaldivar also reviewed Dr. Rasmussen’s exercise blood gas studies and concluded that the studies were invalid. Dr. Zaldivar thus opined in his report that Lane suffered from no respiratory impairment that would prevent him from performing his usual coal mine work.
Dr. Joseph J. Renn examined all of the medical records in the case and rendered a report on March 19, 1987. On the basis of his review, Dr. Renn diagnosed simple pneu-moconiosis, but he concluded that the disease did not prevent Lane from working as an inside laborer at the mine. Like Dr. Zaldi-var, Dr. Renn discussed the exercise arterial blood gas studies that Dr. Rasmussen performed, and Dr. Renn concluded that Dr. Rasmussen’s exercise study was “suspect for validity.”
Dr. Alberto C. Lee examined Lane on June 25,1987. Dr. Lee performed a physical examination, but he did not order any objective testing. Instead, Dr. Lee reviewed the arterial blood gas and pulmonary function studies of the other physicians who had examined Lane. Dr. Lee diagnosed pneumoeo- *170 niosis, found that the arterial blood gas tests revealed a marked impairment in respiratory function, and concluded that the disease totally and permanently disabled Lane from participating in any type of coal mine work.
Finally, Dr. M. Jamil Ahmed examined Lane on June 23, 1987. Dr. Ahmed conducted pulmonary function and resting arterial blood gas studies, and he concluded that the test results were normal.
An AU conducted a hearing and awarded benefits to Lane on March 11, 1988. The AU concluded that Lane was totally disabled due to pneumoconiosis. Union Carbide appealed the decision, and the BRB remanded the case on February 22, 1990 for reconsideration of the evidence relevant to the issues of disability causation and total disability.
On remand, the AU again awarded benefits to Lane. The AU concluded that although the pulmonary function and arterial blood gas studies did not establish total disability, Dr. Rasmussen's medical report did establish total disabffity. Union Carbide appealed, and the BRB again vacated the AU's decision. The BRB affirmed the AU's finding that the objective tests failed to establish total disabifity, but it remanded the claim with instructions to reweigh the medical reports and to decide the disabifity causation issue. The original AU had retired, so the BRB transferred the claim to another AU.
On the second remand, the AU denied benefits on the ground that, although Lane had pneumoconiosis, it did not totally disable him from working. Lane appealed, and the BRB affirmed the AU's denial. The BRB found that the AU permissibly credited the medical reports of Drs. Zaldivar and Renn over the reports of Drs. Rasmussen and Lee. Lane filed a motion for reconsideration en bane, and the BRB issued an en banc decision on November 20, 1995 that affirmed the denial of Lane's claim. Lane now appeals.
II.
We review the AU's findings, as affirmed by the BRB, to determine whether they are supported by substantial evidence and in accordance with the law. Richardson v. Director, OWCP,
The benefit eigibifity regulations listed in 20 C.F.R. Part 718 apply to claims, such as the instant one, filed after April 1, 1980. Robinson v. Pickands Mather & Co.,
The applicable regulations provide that a miner is considered "totally disabled" if pneumoconiosis prevents the miner from performing his usual coal mine employment and from engaging in gainful employment in the geographic area that he resides in. 20 C.F.R. § 718.204(b). Section 718.204(c) provides four specific methods for establishing total disabffity. In the absence of contrary probative evidence, the miner can establish total disabifity by introducing any of the following: 1) pulmonary function studies that show values equal to or less than the values listed in Appendix B of Part 718; 2) arterial blood gas studies that show the values listed in Appendix C of Part 718; 3) evidence that the miner has pneumoconiosis and suffers from cor pulmonale with right-sided congestive heart failure; or 4) a physician's report *171 based on medically acceptable clinical and laboratory diagnostic techniques that concludes that the miner’s respiratory or pulmonary condition prevents him from engaging in his usual coal mine employment. 20 C.F.R. § 718.204(e)(l)-(4).
The miner can establish total disability upon a mere showing of evidence that satisfies any one of the four alternative methods, but only “[i]n the absence of contrary probative evidence.” 20 C.F.R. § 718.204(e). Thus, if the miner makes such a showing, the ALJ must then determine whether the record contains contrary probative evidence. Shedlock v. Bethlehem Mines Corp., 9 BLR 1-195 (Ben.Rev.Bd.1986), aff'd on recon. en banc, 9 BLR 1-236 (Ben.Rev.Bd.1987). If contrary evidence does exist, the ALJ must assign the contrary evidence appropriate weight and determine whether it outweighs the evidence that supports a finding of total disability. Id.
In the instant case, Lane clearly failed to establish total disability through pulmonary function studies. The various doctors performed five pulmonary function studies on Lane, and all of the studies showed values well above the values listed in Appendix B. Lane also failed to present any evidence that he suffers from cor pulmonale -with right-sided congestive heart failure.
Thus, the only issues that we must decide are whether Lane established total disability pursuant to § 718.204(c)(2) through Dr. Rasmussen’s arterial blood gas studies or pursuant to § 718.204(c)(4) through the medical reports of Drs. Rasmussen and Lee. The first ALJ opinion concluded that Lane had established total disability pursuant to § 718.204(c)(2) through Dr. Rasmussen’s arterial blood gas studies. However, in the first remand, the ALJ reversed his earlier holding and concluded that the arterial blood gas studies did not establish total disability. Lane, however, argues on appeal that the arterial blood gas studies in fact do establish total disability pursuant to § 718.204(c)(2).
The various doctors performed five arterial blood gas studies on Lane that tested him both at rest and after exercise. Dr. Rasmussen’s 1974 resting arterial blood gas study showed a value that failed to establish total disability, but the exercise study showed a value sufficient to establish total disability. Dr. Rasmussen’s 1984 arterial blood gas studies reached the same result, and Dr. Gaziano affirmed the validity of Dr. Rasmussen’s 1984 studies. Thus, Lane adequately demonstrated evidence that supports a finding of total disability under § 718.204(c)(2).
However, the ALJ correctly found that substantial contrary probative evidence also exists. Dr. Olson’s subsequent resting and exercise blood gas studies showed values that failed to establish total disability. Drs. Zal-divar and Ahmed only conducted resting blood gas studies, but they both found values that failed to establish total disability. In addition, both Dr. Zaldivar and Dr. Reed questioned the validity of Dr. Rasmussen’s 1974 and 1984 exercise test results. .
Substantial contrary probative evidence also exists with regard to total disability under § 718.204(c)(4). On the first remand, the ALJ concluded that although the pulmonary function and arterial blood gas studies did not establish total disability pursuant to § 718.204(c)(2), Dr. Rasmussen’s medical report did establish total disability pursuant to § 718.204(c)(4). On the second remand, however, the ALJ concluded that Lane failed to establish total disability pursuant to § 718.204(e)(4).
The physician reports conflict as to whether Lane was totally disabled. Drs. Rasmussen and Lee reported that Lane was totally disabled as a result of his pneumoconiosis. However, they based their opinions entirely on the exercise arterial blood gas studies that Dr. Rasmussen performed. As stated above, Drs. Zaldivar and Ahméd persuasively questioned the validity of those studies, and Drs. Zaldivar and Ahmed both concluded that Lane’s condition did not disable him from working. Moreover, Lane continued to work for nine years after Dr. Rasmussen pronounced him totally disabled and unable to work in 1974, which casts doubt on Dr. Rasmussen’s report.
Thus, although the record contains evidence of total disability, the ALJ correctly determined that contrary probative evidence strongly suggests that Lane’s pneumoeonio- *172 sis did not totally disable him from performing his job as a belt mechanic. Moreover, we think that substantial evidence supports the AU's finding that the contrary evidence outweighs the evidence tending to establish total disability.
Lane, however, presents a variety of arguments contending that the AU improperly weighed the evidence. We assess each of Lane's contentions in turn.
A.
Lane first argues that the AU should have given diminished evidentiary weight to the medical reports of Drs. Zaldli-var and Rena, which questioned Dr. Rasmussen's exercise blood gas studies, because Drs. Zaldivar and Renn were not aware of Dr. Gaziano's validation of Dr. Rasmussen's 1984 blood gas studies at the time that they wrote their reports. In his report, however, Dr. Gaziano supplied no reason for his opinion and merely checked a box indicating that Dr. Rasmussen's tests were technically accurate. Dr. Zaldlivar, on the other hand, explained in detail the medical reasons why he believed that Dr. Rasmussen's tests were inaccurate. In addition, Lane's counsel told Dr. Zaldivar about Dr. Gaziano's contrary opinion during cross examination at the hearing, but Dr. Gaziano's opinion did not alter Dr. Zalclivar's conclusion. Moreover, we must defer to the AU's evaluation of the proper weight to accord conflicting medical opinions. See Stiltner v. Island Creek Coal Co.,
B.
Lane also challenges the credibffity of Drs. Zaldivar and Renn on the ground that their medical reports do not satisfy the Fourth Circuit's standard for total disability set forth in Eagle v. Armco, Inc.,
Lane argues that the AU improperly relied on the medical opinions of Drs. Zaldivar and Renn because neither physician exhibited knowledge of the specific exertional requirements of Lane's employment. However, we specifically held, in an unpublished opinion, that consideration of the exertional requirements of a miner's work was "unnecessary" in a case where the AU credited the reports of physicians who found that the miner "had no respiratory or pulmonary impairment at all, and, therefore, from a respiratory standpoint, could perform any kind of manual labor." Kincaid v. Director, OWCP, No. 94-1738,
In the instant case, Drs. Zaldivar and Renn both concluded that Lane did not suffer from any pulmonary impairment. Therefore, the physicians did not need to consider the exertional requirements of Lane's work.
C.
Lane also contends that Dr. Zaldi-var's opinion was "hostile" to the Act because Dr. Zaldivar noted that early simple coal workers' pneumoconiosis would "not be expected" to cause pulmonary impairment. In Thorn v. Itmann Coal Co.,
In the instant case, Dr. Zaidivar only, stated that simple pneumoconiosis would "not be expected" to cause pulmonary impairment. He did not state that simple coal workers' pneumoconiosis does not "as a rule" cause pulmonary impairment. Only the latter assumption would qualify as an opinion "antithetical" to the Act. Dr. Zaiclivar's analysis demonstrates that he based his opinion on the evidence in the instant case and not upon any "hostile" assumptions. He considered the possibility that Lane's simple pneumoco-niosis caused a totally disabling respiratory impairment, but he concluded that such a disability was not present.
D.
Lane also argues that the AU imper-missibly relied on the resting blood gas studies that Drs. Zaldivar and Ahmed conducted. Both physicians failed to conduct exercise blood gas studies, and Lane correctly points out that the applicable regulations provide that physicians must administer an exercise study unless such a study is medically con-See 20 C.F.R. traindicated. § 718.105(b)(1996).
However, in disparaging the fact that Drs. Zaldivar and Ahmed only conducted resting blood gas studies, Lane ignores the exception where an exercise study is not required: when it is medically contraindicated. Both Dr. Ahmed and Dr. Zaldivar found exercise testing contraindicated due to Lane's hypertension. Thus, Lane's argument that the AU should not have relied on the studies of Drs. Zaldivar and Alimed because they failed to perform exercise studies lacks merit.
E.
Lane next argues that the AU erred in discrediting Dr. Rasmussen's reports. Lane points to a varieiiy of factors, such as Dr. Rasmussen's qualifications and experience, that could bolster Dr. Rasmussen's credibility. However, an AU may reject a medical opinion based on an invalid study. See Director, OWCP v. Siwiec,
F.
Next, Lane contends that the AU erred in failing sufficiently to consider the reports of Drs. Gaziano and Lee. Although Lane does not state the basis for his challenge, we presume he contends that the A.LJ violated the Administrative Procedure Act (the "APA"), 5 U.S.C.A. § 557(c)(3)(A) (West 1996), which provides that all AU opinions must include a statement of "findings and conclusions, and the reasons or basis therefor, on all the material issues of fact, law, or discretion presented on the record." In order to comply with the APA, the AU must consider all of the relevant evidence.. See Jordan v. Califano,
G.
Finally, Lane argues that because the AU originally awarded benefits in 1988 and on remand in 1991, extraordinary justification is required for the AU's denial of benefits on the second remand. He contends that the AU erred on the second remand when he reversed, without explanation, the prior AU's findings.
Lane's argument lacks merit. The BRB held that the prior AU decision contained errors. The BRB vacated the prior AU's finding and instructed the AU to reconsider the relevant evidence, with no instructions or assurances that the AU was to reach the same result. When the BRB enters such a remand order, the AU may fully consider whether the claimant satisfied his or her burden of proving the element at issue. Lane concedes that the BRB's decision returned the parties to the status quo ante the prior AU's decision, but he nonetheless argues, without citation to authority, that the AU had to explain his reasons for a contrary finding on the second remand. Lane's theory, that the two prior awards of benefits entitle him to a presumption of benefits, is untenable. The AU did not err when he reconsidered the weight of the relevant evidence, pursuant to the BRB's order, on the second remand.
III.
In summary, we find no defects in the opinions of Drs. Zaldivar and Renn that required the AU to discount their credibffity. Although Lane produced medical opinions in support of his benefits claim, the record also contains medical opinions that refute total disabifity. We must affirm the AU's resolution of the conflicting medical evidence as long as substantial evidence supports his resolution. We find that substantial evidence does support the AU's decision to deny benefits, and we therefore affirm.
AFFIRMED.