                                PUBLISHED

                  UNITED STATES COURT OF APPEALS
                      FOR THE FOURTH CIRCUIT


                               No. 12-2034


WEST VIRGINIA CWP FUND, as insurer for Logan Coals, Inc.,

                Petitioner,

           v.

PAGE BENDER, JR.; DIRECTOR, OFFICE OF WORKERS’ COMPENSATION
PROGRAMS, UNITED STATES DEPARTMENT OF LABOR,

                Respondents.



On Petition for Review of an Order of the Benefits Review Board.
(11-0683-BLA; 10-BLA-5257)


Argued:   January 29, 2015                   Decided:   April 2, 2015


Before KEENAN, FLOYD, and HARRIS, Circuit Judges.


Petition for review denied by published opinion.     Judge Keenan
wrote the opinion, in which Judge Floyd and Judge Harris joined.


ARGUED:   William    Steele   Mattingly,   JACKSON   KELLY   PLLC,
Morgantown,   West   Virginia,   for   Petitioner.  Sean   Gregory
Bajkowski, UNITED STATES DEPARTMENT OF LABOR, Washington, D.C.;
Roger Daniel Forman, LAW OFFICE OF ROGER D. FORMAN, Buckeye,
West Virginia, for Respondents.      ON BRIEF: M. Patricia Smith,
Solicitor of Labor, Rae Ellen James, Associate Solicitor, Maia
S. Fisher, Deputy Associate Solicitor, Gary K. Stearman, Counsel
for Appellate Litigation, Office of the Solicitor, UNITED STATES
DEPARTMENT OF LABOR, Washington, D.C., for Respondent Director,
Office   of  Workers'    Compensation   Programs,  United   States
Department of Labor.
BARBARA MILANO KEENAN, Circuit Judge:

       In     this         appeal,      we      consider          the     validity         of     an

administrative            regulation      and       its    evidentiary          standard    under

which coal mine operators may rebut a presumption of disability

that otherwise qualifies certain coal miners for benefits under

the    Black    Lung        Benefits     Act,       30    U.S.C.      §§ 901      through       945.

Logan Coals, Inc. 1 (the operator) seeks review of a decision of

the    Benefits           Review     Board     affirming         an     administrative           law

judge’s (ALJ) award of benefits to Page Bender, Jr. under the

Act.       Because Bender had worked as an underground coal miner for

21    years    and        suffered      from    a    totally        disabling        respiratory

condition,          the    ALJ     applied      to       Bender’s       claim    a   rebuttable

presumption          of     total      disability         due    to     pneumoconiosis,           as

provided       by    30     U.S.C.     § 921(c)(4)         and     20    C.F.R.      § 718.305. 2

After considering the medical evidence, the ALJ concluded that

the    operator           had    not     rebutted         the     presumption         of    total

disability      due        to    pneumoconiosis           by    “ruling    out”      any   causal


       1
       The named petitioner in this appeal is the West Virginia
Coal Workers’ Pneumoconiosis Fund, insurer for Logan Coals, Inc.
       2
       As discussed further below, at the time the ALJ and the
Board rendered their decisions, the current version of Section
718.305 was not yet in effect.      The parties agree that the
current version of the regulation applies to this case and is
substantively identical to the standard used by the ALJ. See 20
C.F.R. § 718.305(a) (explaining that the presumption applies to
“all claims filed after January 1, 2005, and pending on or after
March 23, 2010”).


                                                 2
relationship between Bender’s pneumoconiosis and his disability.

The ALJ therefore awarded black lung benefits to Bender, and the

Benefits Review Board affirmed the ALJ’s decision.

      In its petition for review, the operator argues that the

ALJ   erred   in   applying     the    “rule-out”     rebuttal      standard.     We

disagree and hold that the Department of Labor acted within its

regulatory authority in requiring coal mine operators to show,

in the case of miners who meet the statutory criteria for the

presumption,       that   “no   part     of     the   miner’s    respiratory      or

pulmonary total disability was caused by pneumoconiosis.”                         20

C.F.R. § 718.305(d).          We also hold that the ALJ’s decision is

supported by substantial evidence.                Accordingly, we affirm the

award of benefits and deny the operator’s petition for review.



                                         I.

      We begin by stating the statutory and regulatory framework,

including certain pertinent history.                  The Black Lung Benefits

Act (the Act), 30 U.S.C. §§ 901 through 945, was first enacted

in 1969. 3    See Pauley v. BethEnergy Mines, Inc., 501 U.S. 680,

683-84    (1991)    (describing       history    of   the   Act).     The   Act   is

intended “to provide benefits . . . to coal miners who are

totally disabled due to pneumoconiosis [(black lung disease)]

      3
       The Act was originally titled the Federal Coal Mine Health
and Safety Act of 1969, 91 Pub. L. No. 173, 83 Stat. 792.


                                         3
and to the surviving dependents of miners whose death was due to

such disease.”         30 U.S.C. § 901(a).

       In     general,     to    establish       an    entitlement   to     black     lung

benefits, a miner must show: “(1) that he has pneumoconiosis, in

either        its     ‘clinical’       or    ‘legal’       form;     (2)     that      the

pneumoconiosis arose out of coal mine employment; (3) that he is

totally disabled by a pulmonary or respiratory impairment; and

(4)    that    his     pneumoconiosis       is     a   substantially       contributing

cause of his total disability.”                  Mingo Logan Coal Co. v. Owens,

724    F.3d         550,   555     (4th     Cir.       2013)   (citing      20   C.F.R.

§§ 725.202(d)(2),           718.204(c)(1)).                Pneumoconiosis        is     a

“substantially contributing cause” of a miner’s disability if

the pneumoconiosis (1) “[h]as a material adverse effect on the

miner’s respiratory or pulmonary condition” or (2) “[m]aterially

worsens a totally disabling respiratory or pulmonary impairment

which is caused by a disease or exposure unrelated to coal mine

employment.”         20 C.F.R. § 718.204(c)(1).

       In 1972, Congress added to the Act a rebuttable presumption

of    total    disability        due   to   pneumoconiosis      (the     presumption).

See Black Lung Benefits Act of 1972, 92 Pub. L. No. 303, 86

Stat. 150, 154; 30 U.S.C. § 921(c)(4) (2012). 4                      The presumption



       4
       When referencing prior versions of the Act and certain
regulations, our citations refer to the date of the latest
(Continued)
                                             4
is applicable to a miner’s claim if he worked for at least 15

years in underground coal mines, if a chest x-ray does not show

the   presence     of   complicated    pneumoconiosis, 5     and     “if     other

evidence   demonstrates     the    existence     of    a   totally    disabling

respiratory   or    pulmonary     impairment.”        § 921(c)(4).         Section

921(c)(4) also specifies the manner in which the Secretary of

Labor 6 (the Secretary) can rebut the presumption:




publication of the United States Code or Code                        of    Federal
Regulations in which the relevant language appeared.
      5
        A miner suffering from complicated pneumoconiosis is
entitled to an irrebuttable presumption that he is totally
disabled due to pneumoconiosis. 30 U.S.C. § 921(c)(3).
      6
        At the time the presumption first was added to the
statute, the reference in Section 921(c)(4) to the “Secretary”
likely referred to the Secretary of Health, Education, and
Welfare, who was responsible for claims filed until June 30,
1973.   Usery v. Turner Elkhorn Mining Co., 428 U.S. 1, 8, 35
(1976).
     Such claims filed on or before June 30, 1973 were processed
by the Social Security Administration, and successful claims
were paid by the federal government. Mullins Coal Co. v. Dir.,
Office of Workers’ Comp. Programs, 484 U.S. 135, 138-39 (1987).
Claims filed on or after July 1, 1973 “are paid by private
employers or by a fund to which the employers contribute, and
they are administered by the Director of the Office of Workers’
Compensation Programs pursuant to regulations promulgated by the
Secretary of Labor.” Id. at 139.
     Since January 31, 2003, the Department of Labor has been
responsible for administering the entirety of the black lung
benefits    program.     See   Black   Lung   Consolidation   of
Administrative Responsibility Act, 107 Pub. L. No. 275, 116
Stat. 1925 (2002).    The current version of the Act specifies
that the term “Secretary” in the Act refers to the Secretary of
Labor.    30 U.S.C. § 902(c).    Today, the federal government
through the Black Lung Disability Trust Fund pays black lung
(Continued)
                                      5
      The Secretary may rebut such presumption only by
      establishing that (A) such miner does not, or did not,
      have pneumoconiosis, or that (B) his respiratory or
      pulmonary impairment did not arise out of, or in
      connection with, employment in a coal mine.

      Four years after the presumption was added to the statute,

the Supreme Court decided Usery v. Turner Elkhorn Mining Co.,

428 U.S. 1, 35-37 (1976), holding that the rebuttal provision in

Section   921(c)(4)    applied       by    its    plain    terms   only     to    the

Secretary, not to coal mine operators opposing a miner’s claim

for   benefits.       Later,    in        1980,   the     Department   of        Labor

promulgated a regulation implementing the statutory presumption

and clarifying the rebuttal standard for both the Secretary and

the   coal   mine   operators        (the     original     regulation).           See

Standards for Determining Coal Miners’ Total Disability or Death

Due To Pneumoconiosis, 45 Fed. Reg. 13,678, 13,692 (Feb. 29,

1980); 20 C.F.R. § 718.305 (2012).                The original regulation set

forth the rebuttal standard as follows:

      Where the cause of death or total disability did not
      arise in whole or in part out of dust exposure in the
      miner’s   coal   mine  employment  or   the  evidence
      establishes that the miner does not or did not have
      pneumoconiosis, the presumption will be considered
      rebutted.   However, in no case shall the presumption
      be considered rebutted on the basis of evidence
      demonstrating the existence of a totally disabling



benefits to miners when, among other reasons, “there is                            no
operator who is liable for the payment of such benefits.”                          26
U.S.C. § 9501(d)(1)(B).



                                          6
     obstructive   respiratory          or     pulmonary     disease     of
     unknown origin.

§ 718.305(d) (2012) (emphasis added).

     In    1981,    however,     Congress       entirely      eliminated      the

statutory presumption from Section 921(c)(4) for claims filed on

or after January 1, 1982.            See Black Lung Benefits Revenue Act

of 1981, 97 Pub. L. No. 119, 95 Stat. 1635.                      The original

regulation was amended in 1983 to reflect this statutory change,

but remained in effect as originally written for claims filed

before January 1, 1982. 7

     The presumption was restored to the statute in March 2010,

as part of the Patient Protection and Affordable Care Act.                    See

Patient Protection and Affordable Care Act, 111 Pub. L. No. 148,

124 Stat. 119, § 1556 (2010).                In reenacting this provision,

Congress    used   language     identical      to     that   employed    in   the

original    statute.      See   30    U.S.C.    § 921(c)(4)    (2012).        This

revived statutory presumption remains in effect at the time of

this appeal.

     In    2013,   the   Department     of    Labor   promulgated   a    revised

regulation (the revised regulation, or the regulation), which is


     7
       Standards for Determining Coal Miner’s Total Disability or
Death Due to Pneumoconiosis; Claims for Benefits Under Part C of
Title IV of the Federal Mine Safety and Health Act, as Amended,
48 Fed. Reg. 24,272, 24,289 (May 31, 1983); see 20 C.F.R.
§ 718.305(e) (2013). The original regulation otherwise remained
unchanged until 2013.


                                        7
at   issue   in   this   case.    The       revised   regulation    states   the

following evidentiary standard that is required to rebut the

presumption:

      In a claim filed by a miner, the party                   opposing
      entitlement may rebut the presumption by--

             (i) Establishing both that the miner does not, or
             did not, have:

                  (A) Legal pneumoconiosis . . . ; and

                  (B) Clinical pneumoconiosis . . . , arising
                  out of coal mine employment . . . ; or

             (ii) Establishing that no part of the miner’s
             respiratory or pulmonary total disability was
             caused by pneumoconiosis . . . .

20 C.F.R. § 718.305(d)(1) (2014) (emphasis added).                 Although the

language of the revised regulation differs in some respects from

the original regulation, both versions require that any party,

including     a   coal   mine    operator,      who   seeks   to    rebut    the

presumption by disproving disability causation, “rule out” any

connection between a miner’s pneumoconiosis and his disability.

The validity of this “rule-out standard” as applied to coal mine

operators is the primary issue presented in this appeal.



                                     II.

      Bender, who was 60 years old at the time of the ALJ’s

decision, was employed in an underground coal mine for 21 years

and ended his work in the mines around 1995.              Bender also smoked


                                        8
between one and one half and two packs of cigarettes daily for

over 40 years, and continues to smoke three or four cigarettes

per day.        Bender is in poor overall health, and was diagnosed

with lung cancer in 2007.                   As a result of his lung cancer,

Bender has undergone radiation and chemotherapy treatments, as

well as the removal of a portion of his lung.                              He also suffers

from       diabetes,      has    undergone       several         bypass    surgeries,      and

receives oxygen at night and after physical exertion.

       Bender       filed    a   claim    for       black   lung    benefits      in    2009. 8

After a hearing conducted in August 2010, the ALJ applied the

presumption         to    Bender’s    claim         in   light     of     Bender’s     21-year

history of underground coal mine employment and the consensus of

all    the    medical       experts      that    Bender     suffers        from   a    totally

disabling      respiratory        condition.             Under    the     presumption,     the

burden therefore shifted to the operator to disprove Bender’s

entitlement to benefits.

       At the time of the ALJ’s decision, the Department of Labor

had    not    yet    promulgated      the       revised     regulation        imposing     the

current version of the rule-out standard for rebuttal of the

presumption.             However, the ALJ applied an analogous rule-out

standard that this Court had used in the context of a previous


       8
       Bender had filed an earlier claim for benefits in 2003,
which was denied due to his failure to prove that he suffered
from a disability.


                                                9
“interim” presumption, which required the operator to “rule out

any causal relationship between the miner’s disability and his

coal   mine     employment       by     a   preponderance         of    the    evidence”        in

order to rebut the presumption.                       See Stiltner v. Island Creek

Coal Co., 86 F.3d 337, 339 (4th Cir. 1996); see also infra at

26-27 (discussing the interim presumption).

       At the hearing before the ALJ in 2010, the operator offered

the expert opinions of three physicians to rebut the presumption

of Bender’s total disability due to pneumoconiosis.                                 All three

agreed that Bender suffers from simple clinical pneumoconiosis.

The    operator         thus     sought         to     rebut    the       presumption           by

demonstrating          that     Bender’s        respiratory       disability          was      not

caused by his pneumoconiosis.

       The    first     of     the    operator’s        experts,       Dr.    Peter      Tuteur,

chronicled       Bender’s        extensive        medical      history,        including         a

“multiplicity of cigarette smoke induced health problems.”                                     Dr.

Tuteur       opined     that    Bender’s        lung     cancer     and       other      medical

conditions,           including        emphysema         and      chronic          obstructive

pulmonary disease, were not “in any way related to, aggravated

by,    or    caused     by     the    inhalation        of   coal      mine    dust       or   the

development       of     coal        workers’        pneumoconiosis.”              Dr.     Tuteur

explained that he would have expected to find “decreased lung

expansion”       and     “inspiratory           crackling       sounds”        if        Bender’s

pneumoconiosis           had         been    advanced          enough         to         “produce

                                                10
abnormalities           on         physical        examination,”         but         that        these

anticipated symptoms were not present.                                Dr. Tuteur therefore

concluded that Bender’s pneumoconiosis was “present but [had] no

clinical effect.”

      Dr. Tuteur also stated that Bender’s disability was “not

caused in whole or in part by coal workers’ pneumoconiosis or

any   other       chronic          lung     disease       arising      out      of     coal       mine

employment,”           but    instead       resulted          from    Bender’s        history      of

smoking, lung cancer, and cancer treatments.                                  In applying the

rule-out standard, the ALJ accorded Dr. Tuteur’s opinion little

weight      because          Dr.    Tuteur     failed         to     “explain        how    he     can

determine that none of [Bender’s] impairment is due to coal dust

exposure.”

      The operator’s second medical expert, Dr. George Zaldivar,

similarly        testified          that     “all”       of    Bender’s       impairment           was

attributable to Bender’s lung surgery, cancer treatments, and

cigarette use.               Dr. Zaldivar based his opinion in part on an

examination conducted seven years earlier by another doctor.                                        At

that earlier time, Bender already had stopped working in the

mines and was exhibiting early signs of simple pneumoconiosis,

but   had    no       pulmonary       abnormalities.               Because    Bender        had   not

worked      in    a    coal        mine    since    that       earlier       examination,         Dr.

Zaldivar         attributed          Bender’s           respiratory      deterioration             to

smoking     and       lung    cancer.         Dr.       Zaldivar     concluded        that       “zero

                                                   11
percent” of Bender’s respiratory abnormalities were caused by

his coal mine employment.                  As with Dr. Tuteur, the ALJ accorded

little weight to Dr. Zaldivar’s analysis, because Dr. Zaldivar

did not “adequately explain why the worsened results could not

also     be        due   to     coal    workers’      pneumoconiosis,         which   is     a

progressive disease.”

       And, finally, the operator offered the report of Dr. P.

Raphael       Caffrey,         who   reviewed     some    surgical    pathology       slides

that included tissue taken from Bender’s lung in 2008.                                     Dr.

Caffrey       noted      that    lesions     caused      by   pneumoconiosis      occupied

less than five percent of Bender’s observed lung tissue.                                   Dr.

Caffrey therefore concluded that Bender’s respiratory disability

was caused by the removal of lung tissue in treatment of his

cancer, not by pneumoconiosis.

       Bender presented expert medical evidence from Dr. Donald

Rasmussen, who directly contradicted Dr. Caffrey’s opinion that

the presence of pneumoconiosis was too minimal to cause Bender’s

impairment.              Dr.    Rasmussen       explained     that    “[a]     finding      of

limited pneumoconiosis certainly does not exclude Mr. Bender’s

coal mine dust exposure as a contributing cause of his disabling

lung disease.             There is no basis for a conclusion that the

extent        of     pneumoconiosis        is     related     to    pulmonary     function

impairment induced by coal mine dust exposure.”                              Dr. Rasmussen

further        opined         that     although      multiple      factors    could    have

                                                12
contributed to Bender’s respiratory impairment, including lung

surgery, cancer treatments, and smoking, Bender’s exposure to

coal dust was a “material contributor.”

     In considering this conflicting evidence, the ALJ credited

Dr. Rasmussen’s disability causation opinion over Dr. Caffrey’s.

In particular, the ALJ cited Dr. Rasmussen’s explanation that a

finding    of   limited     pneumoconiosis          did    not    exclude    coal      dust

exposure    as      a     cause        of     Bender’s      disabling       respiratory

impairment.        The   ALJ     awarded       black     lung   benefits    to    Bender,

based on the ALJ’s conclusion that the operator had failed to

rebut the presumption by showing that Bender’s pneumoconiosis

did not in any way contribute to his disability.                           The Benefits

Review Board affirmed the ALJ’s decision, and this petition for

review followed.


                                             III.

                                              A.

     We    first    address       the       operator’s    legal    challenge      to   the

“rule-out” rebuttal standard.                  As previously discussed, Section

921(c)(4)       sets     forth     a        rebuttable     presumption       of     total

disability due to pneumoconiosis, as well as a rebuttal standard

applicable to the Secretary:

            [I]f a miner was employed for fifteen years
            or more in one or more underground coal
            mines   .  .  .   and  if   other  evidence
            demonstrates the existence of a totally

                                              13
           disabling     respiratory    or    pulmonary
           impairment, then there shall be a rebuttable
           presumption that such miner is totally
           disabled due to pneumoconiosis. . . . The
           Secretary may rebut such presumption only by
           establishing that (A) such miner does not,
           or did not, have pneumoconiosis, or that (B)
           his respiratory or pulmonary impairment did
           not arise out of, or in connection with,
           employment in a coal mine.

The revised regulation implementing the statutory presumption,

which is at issue in this case, states that “the party opposing

entitlement,” which would include coal mine operators, may rebut

the presumption by

           (i) Establishing both that the miner does not, or
           did not, have:

                 (A) Legal pneumoconiosis . . . ; and

                 (B) Clinical pneumoconiosis . . . , arising
                 out of coal mine employment . . . ; or

           (ii) Establishing that no part of the miner’s
           respiratory or pulmonary total disability was
           caused by pneumoconiosis . . . .

20 C.F.R. § 718.305(d)(1). 9

     In   evaluating     a   regulation   promulgated   by   an    executive

agency,   we   apply   the   principles   of   deference   articulated     in

Chevron   v.   Natural   Resources   Defense    Council,     467   U.S.   837


     9
       “Clinical pneumoconiosis” is “a particular set of diseases
recognized   by    the   medical   community,”   whereas   “legal
pneumoconiosis” is “a broader category that includes any chronic
lung disease arising out of coal mine employment.”     Collins v.
Pond Creek Mining Co., 751 F.3d 180, 182 (4th Cir. 2014); see
also 30 U.S.C. § 902(b); 20 C.F.R. § 718.201(a).


                                     14
(1984).     We first examine “whether Congress has directly spoken

to the precise question at issue.”              Elm Grove Coal Co. v. Dir.,

Office of Workers’ Comp. Programs, 480 F.3d 278, 292 (4th Cir.

2007) (quoting Chevron, 467 U.S. at 842).                    “If the intent of

Congress is clear, that is the end of the matter; for the court,

as well as the agency, must give effect to the unambiguously

expressed intent of Congress.”                Chevron, 467 U.S. at 842-43.

However, “if the statute is silent or ambiguous with respect to

the   specific    issue,”      we   continue   to    the    second   step    of   the

Chevron analysis, and determine “whether the agency’s answer is

based on a permissible construction of the statute,” according

the   agency     considerable       deference.        Id.    at    843     (citation

omitted).

                                        i.

      The operator argues that our analysis is resolved under the

first step of Chevron.          Relying on the Supreme Court’s decision

in    Usery,     which    addressed     the    plain       meaning    of    Section

921(c)(4), the operator contends that the rebuttal standard in

the statute is unambiguous and applies only to the Secretary.

In light of this plain statutory language, the operator asserts

that the statute does not allow for the same standard to be

applied also to operators by way of an agency regulation.                     Thus,

the operator argues that this aspect of the agency’s regulation

should    be   afforded   no    deference,     and   that    a    lesser    rebuttal

                                        15
standard should be applicable to operators.                                  In the operator’s

view, the proper rebuttal standard for operators would be one

that would allow the operator to rebut the statutory presumption

by     showing          that    the        claimant’s          pneumoconiosis        is    not    a

“substantially contributing cause” of his total disability.                                      We

disagree with the operator’s arguments, because we do not think

that the holding in Usery is as broad as the operator maintains.

       In    applying          the    first       step    of     the   Chevron    analysis,      we

employ       “the       traditional          tools       of    statutory      construction       to

ascertain congressional intent.”                              Chamber of Commerce of the

U.S.    v.    NLRB,       721        F.3d    152,    160       (4th    Cir.    2013)      (quoting

Chevron,          467    U.S.        at     842    n.9)        (internal      quotation     marks

omitted).           We    begin       by    considering          the    language     of   Section

921(c)(4)          to    determine          whether        the     statute      is   silent      or

ambiguous regarding the manner in which operators can rebut the

presumption.            See Chamber of Commerce, 721 F.3d at 160.

       We conclude that Section 921(c)(4) is silent regarding the

standard that an operator must meet to rebut the presumption.

The     statutory          presumption              of        total    disability         due    to

pneumoconiosis applies both to the Secretary and to operators.

However,          in     addressing           the        method        for    rebutting         this

presumption, the statute refers only to the Secretary.                                    Although

operators necessarily must meet some unarticulated standard to

rebut       the     presumption,            the    statute       specifies       none.      Thus,

                                                    16
because the statute does not speak to the standard operators

must meet to rebut the presumption, Congress has left a “gap”

for   the    agency    to     fill    by    using     its   delegated      regulatory

authority.

      This   conclusion       is     not   affected    by   the     Supreme   Court’s

decision in Usery, in which the Court evaluated the language of

the original statutory presumption before it was removed from

the statute and later was revived by the Patient Protection and

Affordable Care Act.           In Usery, as noted above, the Court held

that it was “clear as a matter of statutory construction that

the . . . limitation on rebuttal evidence is inapplicable to

operators.”      428 U.S. at 35.

      As we have explained, however, because Section 921(c)(4)

does not address the standard for rebuttal by operators, that

standard may be set by regulation.                  The Court in Usery did not

address any regulation implementing the statute and, crucially,

the Court did not consider the evidentiary standard under which

parties     other    than     the    Secretary      could   rebut    the   statutory

presumption.        Instead, the Court merely was required to address

the   question      whether    the    statutory      rebuttal     standard    applied

equally to operators, when the plain language of that portion of

the statute referred only to the Secretary.                   See id. at 37.       In

its   analysis,      moreover,       the    Court    expressly      left   open   the



                                           17
possibility       that     the     Secretary     could   promulgate       regulations

under the statute. 10          Id. at 37 n.40.

       We   also       observe     that    the    premise    of     the    operator’s

argument, namely, that the rule-out standard is the substantive

equivalent of the statutory rebuttal standard at issue in Usery,

is mistaken.           The rebuttal provision in the statute does not

address the evidentiary standard required to show that a miner’s

impairment       did    not    “arise     out    of,   or   in    connection     with,

employment in a coal mine.”                § 921(c)(4).          The statute merely

identifies the elements of a claim that can be rebutted.                              In

contrast,     the      rule-out      standard     prescribes       the    evidentiary

standard that a party must satisfy to rebut the presumption.

       This distinction explains the Court’s analytical focus in

Usery.      At the time Usery was decided, coal miners could be

compensated under the Act only if their disability was caused by

what    became     known      as   “clinical     pneumoconiosis,”        which   is   “a

particular set of diseases recognized by the medical community.”

       10
         The Court observed that the Secretary of Health,
Education, and Welfare had promulgated regulations imposing on
both operators and the Secretary a rebuttal standard similar to
that set forth in the statute.      See Usery, 428 U.S. at 37
(citing 20 C.F.R. §§ 410.414, 410.454 (1975)). The operators in
Usery did not challenge these regulations and, accordingly, the
Court declined to address them.       Id.    We note that the
regulations in place at the time of Usery mirrored the rebuttal
language in Section 921(c)(4), and did not articulate a rule-out
standard for rebuttal.     See 20 C.F.R. §§ 410.414, 410.454
(1975).



                                           18
Collins v. Pine Creek Mining Co., 751 F.3d 180, 182 (4th Cir.

2014)       (defining    clinical          pneumoconiosis);          Andersen       v.     Dir.,

Office of Workers’ Comp. Programs, 455 F.3d 1102, 1105-06 (10th

Cir.        2006)       (explaining           the         original      definition               of

“pneumoconiosis”         under       the     Act).        Therefore,     in     Usery,      the

operators       argued        that     the     rebuttal       provision        in        Section

921(c)(4) was unconstitutional because it permitted a miner who

qualified for the statutory presumption, but whose disability

was    not    caused     by    a     compensable      disease      under      the    Act,        to

receive an award of benefits.                 See Usery, 428 U.S. at 34-35.

       The    Supreme     Court       avoided       the    operators’       constitutional

challenge       to    Section        921(c)(4)       by     holding     that        only     the

Secretary was bound by the statutory rebuttal limitations.                                   Id.

at 35.        Operators thus were permitted to rebut the statutory

presumption by showing that a miner was disabled by a disease

related to coal dust exposure that was not pneumoconiosis.                                 Id.

       Following the decision in Usery, Congress amended the Act

in 1978 to define compensable pneumoconiosis to include what is

now     known    as     “legal       pneumoconiosis,”         as     well     as     clinical

pneumoconiosis. 11            Black Lung Benefits Reform Act of 1977, 95


       11
        The operator maintains that the 1978 amendments to the
Act “merely codified the existing standard of practice,” under
which miners already could receive benefits for disabling legal
pneumoconiosis at the time of Usery. Even if this assertion is
accurate, however, the Supreme Court in Usery nevertheless
(Continued)
                                              19
Pub. L. No. 239, 92 Stat. 95; see 30 U.S.C. § 902(b) (2012).

Thereafter, the agency promulgated regulations further defining

legal pneumoconiosis as “any chronic lung disease or impairment

and its sequelae arising out of coal mine employment,” including

“any    chronic     restrictive       or    obstructive       pulmonary     disease

arising out of coal mine employment.”                   20 C.F.R. § 718.201(a)(2)

(2014).     Under     this    new    regime,      the    concerns     animating   the

Court’s    decision    in     Usery,       namely,      concerns    about    Section

921(c)(4) preventing an operator from rebutting the presumption

by   showing   that    a     miner   was    not    disabled     due    to   clinical

pneumoconiosis but due to another respiratory disease caused by

his coal mine employment, are no longer present, because all

totally disabling diseases caused by coal dust exposure now are

compensable under the Act.            Accordingly, the Court in Usery did

not consider whether the rule-out standard, as opposed to a more

lenient rebuttal standard, would be a permissible evidentiary

standard for rebuttal under the Act.

       We therefore conclude that Usery did not answer either the

question whether Congress left a gap in Section 921(c)(4) that

the agency was permitted to fill by regulation, or the question




focused on the operators’ argument that the rebuttal limitations
in Section 921(c)(4) improperly allowed an award of benefits
even if a miner’s disability was caused by a non-compensable
disease. Usery, 428 U.S. at 34-35.


                                           20
whether   application    of   the   rule-out       standard   to    coal   mine

operators   in   a   regulation   would   be   a   reasonable      exercise   of

agency authority in filling such a gap in the statute. 12                  Thus,

given the different issue before the Court in Usery, the Court’s

holding does not affect our analysis under the first step of the

Chevron standard.

                                    ii.

     Having identified the gap in Section 921(c)(4) that the

agency was permitted to fill by regulation, we proceed to the

second step of the Chevron analysis, under which we ask whether

the agency’s regulation “is a reasonable choice within [the] gap

left open by Congress.”       Chevron, 467 U.S. at 866.            We defer to

an agency if its “choice represents a reasonable accommodation

of conflicting policies that were committed to the agency’s care

by the statute.”       Id. at 845 (citation omitted).              We will not

disturb the agency’s choice “unless it appears from the statute

or its legislative history that the accommodation is not one

that Congress would have sanctioned.”          Id.

     12
        This Court recently was presented with the question
whether the rebuttal standard in Section 921(c)(4) applies to
operators, after the presumption was revived by the Patient
Protection and Affordable Care Act.   See Mingo Logan Coal Co.,
724 F.3d 550. Although the majority opinion did not address the
question, our colleague Judge Niemeyer considered the language
of the statutory presumption, but did not consider the language
of any regulation, in a concurring opinion, concluding that,
under Usery, the rebuttal standard in the statute does not bind
operators. Id. at 560-61 (Niemeyer, J., concurring).


                                    21
       Additionally, to uphold application of the regulation under

Chevron,   we    are   not    required    to   conclude   that   the   agency’s

construction was the only one that the agency permissibly could

have adopted under the statute, or was the construction a court

would have placed on the statute if presented with the question

in the first instance.          Id. at 843 n.11.        Instead, we evaluate

only whether the regulation is a reasonable exercise of agency

authority.      Id. at 844.

       In making this determination, we first observe that the

rule-out standard was made a part of the Act’s regulatory scheme

in 1980, in the original version of 20 C.F.R. § 718.305.                      See

Standards for Determining Coal Miners’ Total Disability or Death

Due To Pneumoconiosis, 45 Fed. Reg. 13,678, 13,692 (Feb. 29,

1980); 20 C.F.R. § 718.305 (2012) (“Where the cause of death or

total disability did not arise in whole or in part out of dust

exposure . . .         the presumption will be considered rebutted.”)

(emphasis added).         Although Congress necessarily was aware of

this   regulation      when   reenacting      the   statutory   presumption    in

2010, Congress did not insert a different rebuttal standard for

coal mine operators into the statute, or otherwise amend the

statutory language to signal its disagreement with the agency’s

earlier construction of the statute.                We therefore may assume,

in the absence of a contrary showing, that Congress intended to

retain the agency’s interpretation of the prior version of the

                                         22
statute.         See   Lorillard         v.    Pons,      434     U.S.       575,   580     (1978)

(“Congress       is    presumed     to       be    aware    of     an       administrative     or

judicial        interpretation          of     a       statute        and     to    adopt    that

interpretation when it re-enacts a statute without change.”).

     The        rule-out    standard          unquestionably            advances      Congress’

purpose     in     enacting        the       statutory          presumption.           Congress

instituted the statutory presumption to make it easier for those

miners most likely to be disabled due to coal dust exposure to

obtain benefits, in response to the high rate of claim denials

that miners experienced without the statutory presumption.                                    See

Pauley, 501 U.S. at 685-86 (discussing the original statutory

presumption       as     passed    in    1972);         Regulations          Implementing      the

Byrd Amendments to the Black Lung Benefits Act: Determining Coal

Miners’ and Survivors’ Entitlement to Benefits, 78 Fed. Reg.

59,102, 59,106-07 (2013) (“Congress adopted the presumption to

relax     the    often     insurmountable              burden    of    proving      eligibility

these miners faced.”) (citation, internal quotation marks, and

alteration omitted).              The strict nature of the regulatory rule-

out standard furthers this goal by placing a significant burden

on operators seeking to rebut the statutory presumption. 13


     13
        The operator also contends that the rule-out standard
violates the principle articulated in Director, Office of
Workers’ Comp. Programs v. Greenwich Collieries, 512 U.S. 267
(1994), which held that under the Administrative Procedure Act,
the proponent of a rule or order must meet his burden by a
(Continued)
                                                  23
     We further observe that, in practice, operators will be

required    to   satisfy    the      rule-out       standard          only    in    a    clearly

defined    class   of    black       lung    claims.            The    rule-out         standard

applies only when (1) a miner has worked for 15 years or more in

an   underground     coal       mine,       (2)     he    suffers          from    a     totally

disabling     respiratory       or    pulmonary          impairment,          and       (3)    the

operator    cannot      satisfy      the     first       method       of     rebuttal         under

Section     718.305(d),         namely,           disproving          the      presence         of

pneumoconiosis.      This class of cases is indisputably serious and

encompasses claimants whose disabilities likely are attributable

at least in part to pneumoconiosis.

     And, critically, the intent of Congress in enacting the

presumption      would     be     thwarted         if     the     operator’s            proposed

“alternative” rebuttal standard were applied.                              As noted above,

in place of the rule-out standard, the operator asserts that it

should be allowed to rebut the statutory presumption by showing




preponderance of the evidence.   Id. at 277-78.    However, “the
preponderance standard goes to how convincing the evidence in
favor of a fact must be . . . before that fact may be found, but
does not determine what facts must be proven as a substantive
part of a claim or defense.” Metro. Stevedore Co. v. Rambo, 521
U.S. 121, 139 n.9 (1997).         Here, the rule-out standard
articulates “only what facts must be established to rebut the
presumption,” and is therefore consistent with Collieries.
Regulations Implementing the Byrd Amendments to the Black Lung
Benefits   Act:   Determining  Coal    Miners’  and   Survivors’
Entitlement to Benefits, 78 Fed. Reg. 59,102, 59,107 (Sept. 25,
2013).


                                             24
that    the    claimant’s       pneumoconiosis          is     not    a   “substantially

contributing cause” of his total disability.

       This “alternative” rebuttal standard, however, effectively

would nullify the statutory presumption for coal miners such as

Bender whom Congress intended to assist.                          Instead of shifting

the burden of proof to the operator to rule out pneumoconiosis

as a cause of the miner’s disability, the operator’s proposed

rebuttal standard would track, in the negative, the evidentiary

burden placed on a miner who has not qualified for the statutory

presumption,         namely,     to       show       that     pneumoconiosis         is     a

“substantially contributing cause” of his total disability.                               See

20 C.F.R. § 718.204(c)(1); Mingo Logan Coal Co., 724 F.3d at

555.          Thus,    to      counter          an    operator’s          evidence    that

pneumoconiosis was not “a substantially contributing cause” of

the    miner’s    disability,         a    miner      entitled       to   the    statutory

presumption nevertheless would be placed back at “square one,”

forced to prove the “substantial” impact of pneumoconiosis on

his    disability,      which    is       the    very       situation     that   Congress

intended to eliminate in enacting the presumption.                           See Pauley,

501 U.S. at 685-86.

       Next, we observe that one of our sister circuits recently

considered     the    present     issue     whether         the   regulatory      rule-out

standard lawfully applies to coal mine operators, and reached

the same conclusion that we do.                      See Big Branch Res., Inc. v.

                                            25
Ogle, 737 F.3d 1063 (6th Cir. 2013).                       In its decision, the Sixth

Circuit        rejected       the    operator’s           argument      under    Usery     and

affirmed application of the regulatory rule-out standard to coal

mine operators.           Id. at 1069-71.             The court explained that to

rebut the statutory presumption of disability, an employer must

show under the rule-out standard that “the [miner’s] coal mine

employment       played       no     part     in    causing       the    [miner’s]       total

disability. . . .”            Id. at 1071 (emphasis in original).

      Our analysis of an earlier regulation in Bethlehem Mines

Corp.     v.     Massey,       736    F.2d     120        (4th    Cir.    1984),     further

reinforces       our    conclusion          that    the     present      regulation      is    a

reasonable exercise of agency authority.                          We reviewed in Massey

an    interim          regulation,          which         established       a    rebuttable

presumption of total disability due to pneumoconiosis when a

miner had worked for at least 10 years in coal mine employment

and suffered from a chronic respiratory or pulmonary disease.

See   id.;      see    also    Stiltner,       86    F.3d    at    339    (describing      the

interim      presumption);           Mullins       Coal    Co.    v.     Dir.,   Office       of

Workers’ Comp. Programs, 484 U.S. 135, 138-39 (1987) (explaining

the   applicability           of    interim    versus       permanent      regulations        to

certain types of claims).                   The presumption at issue in Massey

could be rebutted under the agency regulation by showing that

the miner’s disability did not “arise in whole or in part out of



                                               26
coal mine employment.”                   Massey, 736 F.2d at 123 (quoting 20

C.F.R. § 727.203(b)(3)) (emphasis in original).

      Similar        to    the       operator’s       position       here,    the    coal    mine

operator in Massey argued that it should have been allowed to

rebut    the     interim          presumption         of    disability        under       Section

727.203(b)(3) by showing that “the claimant’s pneumoconiosis is

but     one     of        several       factors        contributing          to     his     total

disability.”              Id.    at    122-23.         Rejecting       this       argument,    we

explained       in    Massey          that    the     rule-out        standard       reasonably

reflected the reality that the convergence of many medical and

environmental        factors          often   will     cause     a    miner’s       disability.

See id. at 124.                 We observed that the rule-out standard was

consistent       with          the    “letter       and     spirit”     of     the    Act,    by

eliminating      the       burden       of    proving       causation        for    miners    who

likely    suffer      from       disabling       pneumoconiosis.             Id.      Thus,   we

affirmed       the    rule-out          standard       in    the      interim       regulation,

concluding      that        the       standard      was     “within     [the       Secretary’s]

rulemaking authority and served the broad remedial purposes of

the statute.”         Id.

      As reflected by our decision in Massey, deference to the

agency’s interpretation is particularly appropriate here because

Congress, through the Act, has “produced a complex and highly

technical regulatory program” in which “[t]he identification and

classification            of     medical      eligibility            criteria       necessarily

                                                 27
require     significant    expertise       and   entail     the       exercise   of

judgment grounded in policy concerns” entrusted to the agency.

Pauley, 501 U.S. at 697.             Thus, in the absence of explicit

direction from Congress, the procedures under which a claimant

may   establish    entitlement   to     benefits    are     a     quintessential

policy judgment best left to the agency.             See id. at 696 (“When

Congress, through . . . the introduction of an interpretive gap

in    the    statutory    structure,       has    delegated        policy-making

authority to an administrative agency, the extent of judicial

review of the agency’s policy determinations is limited.”).

      Although    the     rule-out     standard     undeniably          places    a

substantial burden on coal mine operators, we cannot say that

the   agency     acted    unreasonably      in    issuing       the     regulation

containing the present rule-out standard. 14          Accordingly, we hold



      14
        The operator also argues that it lacked notice of the
rule-out standard during the administrative proceedings in this
case and, therefore, that its due process rights will be
violated if we affirm the rule-out standard without permitting
the operator to present new rebuttal evidence.     The operator,
however, agrees that we should address in this appeal the
validity of the rule-out standard established in Section
718.305(d).
     We conclude that the operator’s argument that it lacked
notice of the rule-out standard is without merit. The original
version of Section 718.305(d), which the agency promulgated in
1980, similarly required operators to rule out disability
causation in order to rebut the statutory presumption in Section
921(c)(4).   The original regulation, applicable to claims filed
through 1981, remained intact until the 2013 amendments at issue
in this case.
(Continued)
                                      28
that the rule-out standard set forth in Section 718.305(d) is a

reasonable exercise of the agency’s authority under Chevron, and

lawfully   applies     to    coal    mine       operators     as    well    as     to    the

Secretary.         Therefore,        as        specifically        provided       in     the

regulation,   any     “party    opposing          entitlement”        to    black       lung

benefits, including coal mine operators, may rebut the statutory

presumption   of     disability      under       subsection    (d)(1)(ii)          of    the

regulation    only    by     proving       that     “no   part      of     the     miner’s

respiratory    or     pulmonary       total        disability        was    caused        by

pneumoconiosis.”      20 C.F.R. § 718.305(d).

                                          B.

     The operator argues, nevertheless, that the ALJ’s decision

awarding   benefits     is    not    supported       by     substantial          evidence,

because the ALJ improperly declined to credit the operator’s

medical experts.      The operator contends that, by explaining that

Bender’s disability was caused by his history of smoking, lung

surgery,   lung     cancer,    and     cancer      treatments,        the     operator’s

medical experts ruled out pneumoconiosis as a cause of Bender’s




     We also observe that we applied the rule-out standard to
operators in a case under the original statutory presumption.
See Rose v. Clinchfield Coal Co., 614 F.2d 936, 939 (4th Cir.
1980). As discussed above, we similarly have applied the rule-
out standard over the years to cases involving the interim
presumption. See Stiltner, 86 F.3d at 339; Massey, 736 F.2d at
123.   For these reasons, we reject the operator’s due process
argument.


                                           29
disability.        Because the ALJ applied the rule-out standard in

his analysis of the evidence from the operator’s experts, we

first    explain     the      type    of    proof     that    the   rule-out        standard

requires from a party opposing a miner’s claim.                           We later will

address the ALJ’s evaluation of the medical evidence.

                                              i.

       To    rebut        the        presumption       of      disability           due      to

pneumoconiosis, an operator must establish that “no part of the

miner’s respiratory or pulmonary total disability was caused by

pneumoconiosis.”          20 C.F.R. § 718.305(d).               Therefore, the rule-

out standard is not satisfied by showing that pneumoconiosis was

one     of   several       causes      of     a    miner’s     disability,          or     that

pneumoconiosis was a minor or even an incidental cause of the

miner’s respiratory or pulmonary impairment.                            See Carozza v.

U.S. Steel Corp., 727 F.2d 74, 78 (3d Cir. 1984) (comparing the

interim presumption to Section 921(c)(4), and explaining that

“Congress      did      not     intend       to    exclude     benefits           for     total

disability     resulting        from       multiple    causes,      one      of    which    is

pneumoconiosis”); Massey, 736 F.2d at 123 (“Pneumoconiosis . . .

must be a causative factor in the miner’s total disability, but

it    need   not   be     the   exclusive         causative    factor     rendering         the

claimant totally disabled . . . .”).

       Instead,      an    operator         opposing    an    award     of    black        lung

benefits      affirmatively            must       establish     that         the        miner’s

                                              30
disability       is   attributable       exclusively         to   a    cause          or     causes

other than pneumoconiosis.               See Massey, 736 F.2d at 123-24 (to

rebut the interim presumption, an operator must “rule out the

causal relationship between the miner’s total disability and his

coal mine employment”).              Thus, to make the required showing when

a miner has qualified for the statutory presumption, a medical

expert testifying in opposition to an award of benefits must

consider pneumoconiosis together with all other possible causes,

and adequately explain why pneumoconiosis was not at least a

partial     cause       of     the     miner’s         respiratory          or         pulmonary

disability.

                                            ii.

     In reviewing a decision of the Benefits Review Board, we

evaluate     “whether        substantial      evidence       supports            the        factual

findings of the ALJ and whether the legal conclusions of the

Board and ALJ are rational and consistent with applicable law.”

Harman Mining Co. v. Dir., Office of Workers’ Comp. Programs,

678 F.3d 305, 310 (4th Cir. 2012) (citation, internal quotation

marks,     and    alteration         omitted).          We    defer         to        the    ALJ’s

determination         regarding       the    proper      weight        to        be     accorded

competing    medical         evidence,      and   we    “must     be    careful             not   to

substitute our judgment for that of the ALJ.”                         Id.

     In the present case, both Drs. Tuteur and Zaldivar opined

that Bender’s disability was caused by his history of smoking

                                             31
and cancer treatments.                  The ALJ discredited these disability

causation     opinions          because        the    doctors    did        not       adequately

explain, as required under the rule-out standard, why Bender’s

disability         was      not         also         partially        attributable              to

pneumoconiosis.          The ALJ additionally found that, by emphasizing

Bender’s deteriorating condition after leaving the coal mines,

Dr.    Zaldivar    did     not    rule     out       pneumoconiosis         as    a    cause    of

Bender’s disability given the progressive nature of the disease.

       It was within the ALJ’s prerogative as fact-finder to weigh

the     credibility        of     the      experts        and        to     determine          the

persuasiveness of their testimony.                     See Island Creek Coal Co. v.

Compton, 211 F.3d 203, 211 (4th Cir. 2000).                                 “[A]s trier of

fact, the ALJ is not bound to accept the opinion or theory of

any medical expert,” but instead “must evaluate the evidence,

weigh it, and draw his own conclusions.”                             Underwood v. Elkay

Mining, Inc., 105 F.3d 946, 949 (4th Cir. 1997).                             Here, the ALJ

appropriately       found        that     by     identifying         causes       other      than

pneumoconiosis,          Drs.    Tuteur    and       Zaldivar    failed          to    establish

that    pneumoconiosis           played        “no    part”     in        causing      Bender’s

disability.        And, although Dr. Tuteur identified reasons for

concluding that Bender’s pneumoconiosis had no clinical effect,

the    ALJ   was   not     required       to     find     Dr.    Tuteur’s         explanation

persuasive.         The     ALJ     also        reasonably       determined           that     Dr.

Zaldivar’s causation opinion was inadequately supported.

                                                32
      With   respect    to    Dr.    Caffrey’s    opinion   that   Bender’s

pneumoconiosis was insufficiently severe to be disabling, the

ALJ credited the contrary opinion of Bender’s medical expert,

Dr. Rasmussen, who explained that the extent of pneumoconiosis

as reflected on an x-ray has no bearing on whether the disease

was a cause of a miner’s disability.             It is the prerogative of

the ALJ, rather than of a reviewing court, to resolve such a

battle of the experts.         Westmoreland Coal Co. v. Cochran, 718

F.3d 319, 324 (4th Cir. 2013).             Therefore, we will not disrupt

the ALJ’s decision to credit the opinion of one expert over

another.

      For these reasons, we conclude that the ALJ acted within

his   fact-finding     role   in    weighing   the   credibility   and   the

persuasiveness of the medical expert opinions.              Accordingly, in

view of our deferential standard of review and the high burden

imposed by the rule-out standard, we hold that the ALJ’s factual

determinations are supported by substantial evidence.



                                      IV.

      For these reasons, the operator’s petition for review is

denied.

                                               PETITION FOR REVIEW DENIED




                                      33
