OPINION OF THE COURT

Samuel E. Wensel (Wensel), pro se, petitions for review of an order of the Department of Labor’s Benefits Review Board (Board). The Board affirmed the decision of an administrative law judge (AU), who denied Wensel’s claim for benefits under the Black Lung Benefits Act, 30 U.S.C.A. §§ 901-945 (West 1986).

Both parties state that the Board erred in affirming an erroneous decision by the AU, but they offer different reasons. Wensel states that the AU erred when he concluded that Wensel was not entitled to black lung benefits. The Director, Office of Workers’ Compensation Program (Director), argues that we should remand the case because the AU failed to find facts as required by the Administrative Procedure Act (APA), 5 U.S.C.A. § 557(c)(3)(A) (West 1977). 1 We agree with the Director that a remand is necessary. Therefore, we will vacate the decision of the Board and order it to remand this matter to the AU with directions.

I.

Wensel filed his claim for black lung benefits on April 1, 1982. He claims that he suffers from pneumoconiosis, the medical term for the affliction commonly known as black lung. Black lung is an occupational disease peculiar to the coal mining industry. It is caused by the inhalation of coal dust in the course of coal mine employment. See 20 C.F.R. § 718.201 (1988).

Wensel has argued throughout his battle for benefits that he worked about eighteen years as a coal miner. The AU found from Wensel’s social security records that he worked only twelve and three-quarter years in the mines. The Board affirmed this finding. Wensel says the AU incorrectly failed to credit him with five to six years of work with W.P. Stahlman Coal Co. (Stahlman) of Corsica, Pennsylvania during the 1950’s simply because there was no evidence of Wensel’s work for Stahlman in Wensel’s social security records.

The AU also determined that the medical evidence in the record failed to establish pneumoconiosis. The medical evidence consisted of seven x-ray readings, three pulmonary function tests, five blood gas studies and reports from three physicians. The AU determined that the great numerical weight of “objective” tests and physicians’ opinions were negative for pneumoconiosis, even though one x-ray reading was positive for pneumoconiosis, the blood gas and ven-tilatory studies yielded values indicative of respiratory impairment and one physician who examined Wensel found that he suffered from black lung. The Board affirmed the AU’s determination.

*16 II.

We have jurisdiction pursuant to 30 U.S. C.A. § 932(a) (West 1986), which incorporates the review procedures of the Long-shore and Harbor Workers’ Compensation Act, 33 U.S.C.A. § 921(c) (West 1986), in pneumoconiosis cases involving coal miners. The AU’s findings of fact are conclusive on the Board if supported by substantial evidence. See Marx v. Director, OWCP, 870 F.2d 114, 118 (3d Cir. 1989). “We review the Board’s decision to determine whether it committed an error of law and whether it adhered to its scope of review. In performing the latter function, ‘we must independently review the record “and decide whether the AU’s findings are supported by substantial evidence.” ’ ” Id. (citation omitted) (quoting Kertesz v. Crescent Hills Coal Co., 788 F.2d 158, 163 (3d Cir. 1986) (quoting Walker v. Universal Terminal & Stevedoring Corp., 645 F.2d 170, 172 (3d Cir. 1981) (citation omitted))).

III.

The Director argues that this matter should be remanded to the AU since “[t]he AU’s decision violates the Administrative Procedure Act because it contains neither an accurate discussion of all of the relevant evidence nor an explanation of the findings made by the AU....” Brief for Respondent at 7. The Director points us to 5 U.S.C.A. § 557(c)(3)(A), which states that “[a]ll decisions ... shall include a statement of — (A) findings and conclusions, and the reasons or basis therefor, on all the material issues of fact, law, or discretion presented on .the record.” We have held that an AU working for the Department of Labor must abide by this section of the APA. See Marx, 870 F.2d at 119; Hillibush v. United States Dep’t of Labor, Benefits Review Bd., 853 F.2d 197, 206 & n. 17 (3d Cir. 1988).

We agree with the Director that a remand is necessary for the AU to explain his findings of fact and conclusions of law with respect to the medical evidence. We cannot determine whether the Board properly exercised its review function if we are unable to understand how the AU reached his decision. Much evidence in the record supports Wensel’s claim that he has black lung. Some of the evidence, however, may support the conclusion that Wensel does not have the disease. The AU has not told us why he accepted the evidence unfavorable to Wensel in making his ruling, except to say that he relied on the predominant weight of the unfavorable evidence. Cf. Cotter v. Harris, 642 F.2d 700 (3d Cir. 1981) (vacating district court order granting Secretary of Health and Human Services summary judgment in social security disability case). In Cotter, we said:

This court has recognized that there is a particularly acute need for some explanation by the AU when s/he has rejected relevant evidence or when there is conflicting probative evidence in the record. We have emphasized our concern in a long line of cases.

Id. at 706.

Items of evidence are not fungible. A bare statement that 'items of evidence pointing one way outnumber or outweigh others pointing in a different direction does not demonstrate a reasoned choice. As we wrote in Kertesz, “[i]n reaching a decision, an AU should set out and discuss the pertinent medical evidence presented.” Kertesz, 788 F.2d at 163. The AU has so far failed to do so. We agree with the Director that the AU must reconsider the evidence, especially since “[t]he evaluation of medical evidence is a task that Congress allocated to the administrators in the first instance.” Bernardo v. Director, OWCP, 790 F.2d 351, 353 (3d Cir. 1986). After he has again reviewed the evidence, the AU must provide an adequate statement of the reasons for his findings.

IV.

Wensel challenges the method the AU used to determine the number of years that he worked as a coal miner. Under the Black Lung Benefits Act, the number of years that a claimant has worked in the mines and the date the claim was filed determine whether the claimant will benefit from one or more of the presumptions that will aid him in showing disability. In general, the presumptions recognize the medi *17 cally established relation between years of exposure to coal dust in coal mining employment and disability from black lung. See 30 U.S.C.A. § 921(c) (West 1986). However, the Director argues that even if Wensel is credited with an extra five to six years of work in the mines, it would not affect the presumption that Wensel already has. Thus, the Director says that even if the AU miscalculated Wensel’s time as a miner, it was harmless error.

The AU noted in his decision that Wensel claimed to have worked as a miner from 1943 to 1945, from 1950 to 1953, from 1955 to 1958 and from 1960 to 1967. Yet the AU wrote: “The Social Security Records document work in the coal mines for 12% years. The claimant can be credited with this length of coal mine employment.” Wensel v. Director, OWCP, No. 84-BLA-9881, slip op. at 2 (U.S. Dep’t of Labor Office of Admin. Law Judges Apr. 6, 1987) (citation omitted). In affirming the AU’s finding that Wensel worked just twelve and three-quarter years, the Board wrote “we affirm the administrative law judge’s determination as to years of coal mine employment as it is based on a reasonable method of calculation and is supported by substantial evidence in the record.” Wensel v. Director, OWCP, No. 87-1165 BLA, slip op. at 2 (U.S. Dep’t of Labor Benefits Review Bd. Jan. 23, 1989).

In so holding, we believe the Board erred. While a person’s social security records are proof of particular employment, the AU mistakenly assumed that the absence of social security records for some years necessarily proved that Wensel was not employed as a coal miner during that time. See Marx, 870 F.2d at 118-19 (absence of social security records does not necessarily prove that the applicant was not employed in the coal mines). Until the AU again reviews the evidence and properly advises us of the reasons for whatever decision he reaches on remand, we cannot decide whether this error was harmless. An additional five or six years of work in the coal mines, if it is shown, could be evidence that supports Wensel’s claim considering the nature of the disease.

However, we agree with the Director that the additional five to six years Wensel claims does not entitle him to the presumption that he has pneumoconiosis. Since Wensel filed his claim for benefits after January 1, 1982, he is unable to claim the rebuttable presumption of pneumoconiosis that was available for claims filed before 1982 when the claimant proved fifteen years of work as a coal miner and submitted certain specified medical evidence. See 20 C.F.R. § 718.305(a), (e) (1988). Congress has eliminated this fifteen year presumption with respect to all claims filed after January 1, 1982. See 30 U.S.C.A. § 921(c)(4) (West 1986). Therefore, we are powerless to treat Wensel’s long employment as a miner in and of itself as proof that he has pneumoconiosis absent further congressional action. 2

Whether Wensel worked twelve and three-quarter years or about eighteen *18 years, he can claim one presumption under the regulations. Since in either case he was employed as a miner for ten years or more, he has the benefit of “a rebuttable presumption that the pneumoconiosis arose out of” his employment in the coal mines. 20 C.F.R. §§ 718.203(b), 718.302 (1988). Therefore, on remand, if the AU determines upon reexamining the evidence that Wensel has established that he suffers from pneumoconiosis, he will have the benefit of a rebuttable presumption that the disease was caused by his employment in the mines. Moreover, in determining whether Wensel has black lung, the AU should consider the relevance of the length of time Wensel worked in the coal mines.

V.

Accordingly, we will remand to the Board and instruct it further to remand the case to the AU with directions that he reexamine the evidence and set forth on the record a discussion of all the evidence along with the reasons for his decision in a manner consistent with this opinion.