(Slip Opinion)              OCTOBER TERM, 2014                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

   INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                    ET AL. 


CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

   No. 13–433.      Argued October 8, 2014—Decided December 9, 2014
Petitioner Integrity Staffing Solutions, Inc., required its hourly ware-
  house workers, who retrieved products from warehouse shelves and
  packaged them for delivery to Amazon.com customers, to undergo a
  security screening before leaving the warehouse each day. Respond-
  ents, former employees, sued the company alleging, as relevant here,
  that they were entitled to compensation under the Fair Labor Stand-
  ards Act of 1938 (FLSA) for the roughly 25 minutes each day that
  they spent waiting to undergo and undergoing those screenings.
  They also alleged that the company could have reduced that time to a
  de minimis amount by adding screeners or staggering shift termina-
  tions and that the screenings were conducted to prevent employee
  theft and, thus, for the sole benefit of the employers and their cus-
  tomers.
     The District Court dismissed the complaint for failure to state a
  claim, holding that the screenings were not integral and indispensa-
  ble to the employees’ principal activities but were instead postlimi-
  nary and noncompensable. The U. S. Court of Appeals for the Ninth
  Circuit reversed in relevant part, asserting that postshift activities
  that would ordinarily be classified as noncompensable postliminary
  activities are compensable as integral and indispensable to an em-
  ployee’s principal activities if the postshift activities are necessary to
  the principal work and performed for the employer’s benefit.
Held: The time that respondents spent waiting to undergo and undergo-
 ing security screenings is not compensable under the FLSA. Pp. 3–9.
    (a) Congress passed the Portal-to-Portal Act to respond to an eco-
 nomic emergency created by the broad judicial interpretation given to
 the FLSA’s undefined terms “work” and “workweek.” See 29 U. S. C.
2          INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                                    Syllabus

    §251(a); Tennessee Coal, Iron & R. Co. v. Muscoda Local No. 123, 321
    U. S. 590, 598. The Portal-to-Portal Act exempted employers from
    FLSA liability for claims based on “activities which are preliminary
    to or postliminary to” the performance of the principal activities that
    an employee is employed to perform. §254(a)(2). Under this Court’s
    precedents, the term “principal activities” includes all activities
    which are an “integral and indispensable part of the principal activi-
    ties.” Steiner v. Mitchell, 350 U. S. 247, 252–253. An activity is “in-
    tegral and indispensable” if it is an intrinsic element of the employ-
    ee’s principal activities and one with which the employee cannot
    dispense if he is to perform his principal activities. This Court has
    identified several activities that satisfy this test—see, e.g., id., at 249,
    251; Mitchell v. King Packing Co., 350 U. S. 260, 262—and Depart-
    ment of Labor regulations are consistent with this approach, see 29
    CFR §§790.8(c), 790.7(g). Pp. 3–7.
       (b) The security screenings at issue are noncompensable postlimi-
    nary activities. To begin with, the screenings were not the principal
    activities the employees were employed to perform—i.e., the workers
    were employed not to undergo security screenings but to retrieve
    products from warehouse shelves and package them for shipment.
    Nor were they “integral and indispensable” to those activities. This
    view is consistent with a 1951 Department of Labor opinion letter,
    which found noncompensable under the Portal-to-Portal Act both a
    preshift screening conducted for employee safety and a postshift
    search conducted to prevent employee theft. The Ninth Circuit’s test,
    which focused on whether the particular activity was required by the
    employer rather than whether it was tied to the productive work that
    the employee was employed to perform, would sweep into “principal
    activities” the very activities that the Portal-to-Portal Act was de-
    signed to exclude from compensation. See, e.g., IBP, supra, at 41.
    Finally, respondents’ claim that the screenings are compensable be-
    cause Integrity Staffing could have reduced the time to a de minimis
    amount is properly presented at the bargaining table, not to a court
    in an FLSA claim. Pp. 7–9.
713 F. 3d 525, reversed.

    THOMAS, J., delivered the opinion for a unanimous Court.                SO-
TOMAYOR, J., fileda concurring opinion, in which KAGAN, J., joined.
                        Cite as: 574 U. S. ____ (2014)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash-
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 13–433
                                   _________________


       INTEGRITY STAFFING SOLUTIONS, INC., 

          PETITIONER v. JESSE BUSK ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                              [December 9, 2014]


  JUSTICE THOMAS delivered the opinion of the Court.
  The employer in this case required its employees, ware-
house workers who retrieved inventory and packaged it
for shipment, to undergo an antitheft security screen-
ing before leaving the warehouse each day. The question
presented is whether the employees’ time spent waiting to
undergo and undergoing those security screenings is
compensable under the Fair Labor Standards Act of 1938
(FLSA), 29 U. S. C. §201 et seq., as amended by the Portal-
to-Portal Act of 1947, §251 et seq. We hold that the time is
not compensable. We therefore reverse the judgment of
the United States Court of Appeals for the Ninth Circuit.
                            I
  Petitioner Integrity Staffing Solutions, Inc., provides
warehouse staffing to Amazon.com throughout the United
States.   Respondents Jesse Busk and Laurie Castro
worked as hourly employees of Integrity Staffing at ware-
houses in Las Vegas and Fenley, Nevada, respectively. As
warehouse employees, they retrieved products from the
shelves and packaged those products for delivery to Ama-
zon customers.
2      INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                     Opinion of the Court

   Integrity Staffing required its employees to undergo a
security screening before leaving the warehouse at the end
of each day. During this screening, employees removed
items such as wallets, keys, and belts from their persons
and passed through metal detectors.
   In 2010, Busk and Castro filed a putative class action
against Integrity Staffing on behalf of similarly situated
employees in the Nevada warehouses for alleged violations
of the FLSA and Nevada labor laws. As relevant here, the
employees alleged that they were entitled to compensation
under the FLSA for the time spent waiting to undergo and
actually undergoing the security screenings. They alleged
that such time amounted to roughly 25 minutes each day
and that it could have been reduced to a de minimis
amount by adding more security screeners or by stagger-
ing the termination of shifts so that employees could flow
through the checkpoint more quickly. They also alleged
that the screenings were conducted “to prevent employee
theft” and thus occurred “solely for the benefit of the em-
ployers and their customers.” App. 19, 21.
   The District Court dismissed the complaint for failure to
state a claim, holding that the time spent waiting for and
undergoing the security screenings was not compensable
under the FLSA. It explained that, because the screenings
occurred after the regular work shift, the employees could
state a claim for compensation only if the screenings were
an integral and indispensable part of the principal activi-
ties they were employed to perform. The District Court
held that these screenings were not integral and indispen-
sable but instead fell into a noncompensable category of
postliminary activities.
   The United States Court of Appeals for the Ninth Cir-
cuit reversed in relevant part. 713 F. 3d 525 (2013). The
Court of Appeals asserted that postshift activities that
would ordinarily be classified as noncompensable postlim-
inary activities are nevertheless compensable as integral
                 Cite as: 574 U. S. ____ (2014)            3

                     Opinion of the Court

and indispensable to an employee’s principal activities if
those postshift activities are necessary to the principal
work performed and done for the benefit of the employer.
Id., at 530. Accepting as true the allegation that Integrity
Staffing required the security screenings to prevent em-
ployee theft, the Court of Appeals concluded that the
screenings were “necessary” to the employees’ primary
work as warehouse employees and done for Integrity
Staffing’s benefit. Id., at 531.
  We granted certiorari, 571 U. S. ___ (2014), and now
reverse.
                              II

                              A

  Enacted in 1938, the FLSA established a minimum
wage and overtime compensation for each hour worked in
excess of 40 hours in each workweek. §§6(a)(1), 7(a)(3), 52
Stat. 1062–1063. An employer who violated these provi-
sions could be held civilly liable for backpay, liquidated
damages, and attorney’s fees. §16, id., at 1069.
  But the FLSA did not define “work” or “workweek,” and
this Court interpreted those terms broadly. It defined
“work” as “physical or mental exertion (whether burden-
some or not) controlled or required by the employer and
pursued necessarily and primarily for the benefit of the
employer and his business.” Tennessee Coal, Iron & R. Co.
v. Muscoda Local No. 123, 321 U. S. 590, 598 (1944).
Similarly, it defined “the statutory workweek” to “includ[e]
all time during which an employee is necessarily required
to be on the employer’s premises, on duty or at a pre-
scribed workplace.” Anderson v. Mt. Clemens Pottery Co.,
328 U. S. 680, 690–691 (1946). Applying these expansive
definitions, the Court found compensable the time spent
traveling between mine portals and underground work
areas, Tennessee Coal, supra, at 598, and the time spent
walking from timeclocks to work benches, Anderson, su-
4      INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                     Opinion of the Court

pra, at 691–692.
   These decisions provoked a flood of litigation. In the six
months following this Court’s decision in Anderson, unions
and employees filed more than 1,500 lawsuits under the
FLSA. S. Rep. No. 37, 80th Cong., 1st Sess., pp. 2–3
(1947). These suits sought nearly $6 billion in back pay
and liquidated damages for various preshift and postshift
activities. Ibid.
   Congress responded swiftly. It found that the FLSA
had “been interpreted judicially in disregard of long-
established customs, practices, and contracts between
employers and employees, thereby creating wholly unex-
pected liabilities, immense in amount and retroactive in
operation, upon employers.” 29 U. S. C. §251(a). Declar-
ing the situation to be an “emergency,” Congress found
that, if such interpretations “were permitted to stand, . . .
the payment of such liabilities would bring about financial
ruin of many employers” and “employees would receive
windfall payments . . . for activities performed by them
without any expectation of reward beyond that included in
their agreed rates of pay.” §§251(a)–(b).
   Congress met this emergency with the Portal-to-Portal
Act. The Portal-to-Portal Act exempted employers from
liability for future claims based on two categories of work-
related activities as follows:
    “(a) Except as provided in subsection (b) [which covers
    work compensable by contract or custom], no employer
    shall be subject to any liability or punishment under
    the Fair Labor Standards Act of 1938, as amended,
    . . . on account of the failure of such employer . . .
    to pay an employee overtime compensation, for or on
    account of any of the following activities of such em-
    ployee engaged in on or after the date of the enact-
    ment of this Act—
    “(1) walking, riding, or traveling to and from the ac-
                  Cite as: 574 U. S. ____ (2014)            5

                      Opinion of the Court

    tual place of performance of the principal activity or ac-
    tivities which such employee is employed to perform,
    and
    “(2) activities which are preliminary to or postlimi-
    nary to said principal activity or activities,
    “which occur either prior to the time on any particular
    workday at which such employee commences, or sub-
    sequent to the time on any particular workday at
    which he ceases, such principal activity or activities.”
    §4, 61 Stat. 86–87 (codified at 29 U. S. C. §254(a)).
At issue here is the exemption for “activities which are
preliminary to or postliminary to said principal activity or
activities.”
                                B
  This Court has consistently interpreted “the term ‘prin-
cipal activity or activities’ [to] embrac[e] all activities
which are an ‘integral and indispensable part of the prin-
cipal activities.’ ” IBP, Inc. v. Alvarez, 546 U. S. 21, 29–30
(2005) (quoting Steiner v. Mitchell, 350 U. S. 247, 252–253
(1956)). Our prior opinions used those words in their
ordinary sense. The word “integral” means “[b]elonging to
or making up an integral whole; constituent, component;
spec[ifically] necessary to the completeness or integrity of
the whole; forming an intrinsic portion or element, as
distinguished from an adjunct or appendage.” 5 Oxford
English Dictionary 366 (1933) (OED); accord, Brief for
United States as Amicus Curiae 20 (Brief for United
States); see also Webster’s New International Dictionary
1290 (2d ed. 1954) (Webster’s Second) (“[e]ssential to
completeness; constituent, as a part”). And, when used to
describe a duty, “indispensable” means a duty “[t]hat
cannot be dispensed with, remitted, set aside, disregarded,
or neglected.” 5 OED 219; accord, Brief for United States
19; see also Webster’s Second 1267 (“[n]ot capable of being
dispensed with, set aside, neglected, or pronounced nonob-
6      INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                     Opinion of the Court

ligatory”). An activity is therefore integral and indispen-
sable to the principal activities that an employee is em-
ployed to perform if it is an intrinsic element of those
activities and one with which the employee cannot dis-
pense if he is to perform his principal activities. As we
describe below, this definition, as applied in these circum-
stances, is consistent with the Department of Labor’s
regulations.
   Our precedents have identified several activities that
satisfy this test. For example, we have held compensable
the time battery-plant employees spent showering and
changing clothes because the chemicals in the plant were
“toxic to human beings” and the employer conceded that
“the clothes-changing and showering activities of the
employees [were] indispensable to the performance of
their productive work and integrally related thereto.”
Steiner, supra, at 249, 251. And we have held compensa-
ble the time meatpacker employees spent sharpening their
knives because dull knives would “slow down production”
on the assembly line, “affect the appearance of the meat as
well as the quality of the hides,” “cause waste,” and lead to
“accidents.” Mitchell v. King Packing Co., 350 U. S. 260,
262 (1956). By contrast, we have held noncompensable
the time poultry-plant employees spent waiting to don
protective gear because such waiting was “two steps re-
moved from the productive activity on the assembly line.”
IBP, supra, at 42.
   The Department of Labor’s regulations are consistent
with this approach. See 29 CFR §790.8(b) (2013) (“The
term ‘principal activities’ includes all activities which are
an integral part of a principal activity”); §790.8(c) (“Among
the activities included as an integral part of a principal
activity are those closely related activities which are
indispensable to its performance”). As an illustration,
those regulations explain that the time spent by an em-
ployee in a chemical plant changing clothes would be
                 Cite as: 574 U. S. ____ (2014)            7

                     Opinion of the Court

compensable if he “c[ould not] perform his principal activi-
ties without putting on certain clothes” but would not be
compensable if “changing clothes [were] merely a conven-
ience to the employee and not directly related to his prin-
cipal activities.” See §790.8(c). As the regulations explain,
“when performed under the conditions normally present,”
activities including “checking in and out and waiting in
line to do so, changing clothes, washing up or showering,
and waiting in line to receive pay checks” are “ ‘prelimi-
nary’ ” or “ ‘postliminary’ ” activities. §790.7(g).
                              III

                               A

  The security screenings at issue here are noncompensa-
ble postliminary activities. To begin with, the screenings
were not the “principal activity or activities which [the]
employee is employed to perform.” 29 U. S. C. §254(a)(1).
Integrity Staffing did not employ its workers to undergo
security screenings, but to retrieve products from ware-
house shelves and package those products for shipment to
Amazon customers.
  The security screenings also were not “integral and
indispensable” to the employees’ duties as warehouse
workers. As explained above, an activity is not integral
and indispensable to an employee’s principal activities
unless it is an intrinsic element of those activities and one
with which the employee cannot dispense if he is to per-
form those activities. The screenings were not an intrinsic
element of retrieving products from warehouse shelves or
packaging them for shipment. And Integrity Staffing
could have eliminated the screenings altogether without
impairing the employees’ ability to complete their work.
  The Solicitor General, adopting the position of the De-
partment of Labor, agrees that these screenings were
noncompensable postliminary activities. See Brief for
United States 10. That view is fully consistent with an
8      INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                     Opinion of the Court

Opinion Letter the Department issued in 1951. The letter
found noncompensable a preshift security search of em-
ployees in a rocket-powder plant “ ‘for matches, spark
producing devices such as cigarette lighters, and other
items which have a direct bearing on the safety of the
employees,’ ” as well as a postshift security search of the
employees done “ ‘for the purpose of preventing theft.’ ”
Opinion Letter from Dept. of Labor, Wage and Hour Div.,
to Dept. of Army, Office of Chief of Ordnance (Apr. 18,
1951), pp. 1–2 (available in Clerk of Court’s case file). The
Department drew no distinction between the searches
conducted for the safety of the employees and those con-
ducted for the purpose of preventing theft—neither were
compensable under the Portal-to-Portal Act.
                              B
  The Court of Appeals erred by focusing on whether an
employer required a particular activity. The integral and
indispensable test is tied to the productive work that the
employee is employed to perform. See, e.g., IBP, 546 U. S.,
at 42; Mitchell, supra, at 262; Steiner, 350 U. S., at 249–
251; see also 29 CFR §790.8(a) (explaining that the term
“principal activities” was “considered sufficiently broad to
embrace within its terms such activities as are indispen-
sable to the performance of productive work” (internal
quotation marks omitted; emphasis added)); §790.8(c)
(“Among the activities included as an integral part of a
principal activity are those closely related activities which
are indispensable to its performance” (emphasis added)).
  If the test could be satisfied merely by the fact that an
employer required an activity, it would sweep into “princi-
pal activities” the very activities that the Portal-to-Portal
Act was designed to address. The employer in Anderson,
for instance, required its employees to walk “from a
timeclock near the factory gate to a workstation” so that
they could “begin their work,” “but it is indisputable that
                  Cite as: 574 U. S. ____ (2014)            9

                      Opinion of the Court

the Portal-to-Portal Act evinces Congress’ intent to repu-
diate Anderson’s holding that such walking time was
compensable under the FLSA.” IBP, supra, at 41. A test
that turns on whether the activity is for the benefit of the
employer is similarly overbroad.
  Finally, we reject the employees’ argument that time
spent waiting to undergo the security screenings is com-
pensable under the FLSA because Integrity Staffing could
have reduced that time to a de minimis amount. The fact
that an employer could conceivably reduce the time spent
by employees on any preliminary or postliminary activity
does not change the nature of the activity or its relation-
ship to the principal activities that an employee is em-
ployed to perform. These arguments are properly present-
ed to the employer at the bargaining table, see 29 U. S. C.
§254(b)(1), not to a court in an FLSA claim.
                        *    *     *
  We hold that an activity is integral and indispensable to
the principal activities that an employee is employed to
perform—and thus compensable under the FLSA—if it is
an intrinsic element of those activities and one with which
the employee cannot dispense if he is to perform his prin-
cipal activities. Because the employees’ time spent wait-
ing to undergo and undergoing Integrity Staffing’s security
screenings does not meet these criteria, we reverse the
judgment of the Court of Appeals.
                                             It is so ordered.
                 Cite as: 574 U. S. ____ (2014)            1

                   SOTOMAYOR, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                          No. 13–433
                         _________________


      INTEGRITY STAFFING SOLUTIONS, INC., 

         PETITIONER v. JESSE BUSK ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                      [December 9, 2014]


    JUSTICE SOTOMAYOR, with whom JUSTICE KAGAN joins,
concurring.
    I concur in the Court’s opinion, and write separately
only to explain my understanding of the standards the
Court applies.
    The Court reaches two critical conclusions. First, the
Court confirms that compensable “ ‘principal’ ” activities
“ ‘includ[e] . . . those closely related activities which are
indispensable to [a principal activity’s] performance,’ ”
ante, at 6 (quoting 29 CFR §790.8(c)(2013)), and holds that
the required security screenings here were not “integral
and indispensable” to another principal activity the em-
ployees were employed to perform, ante, at 7. I agree. As
both Department of Labor regulations and our precedent
make clear, an activity is “indispensable” to another,
principal activity only when an employee could not dis-
pense with it without impairing his ability to perform the
principal activity safely and effectively. Thus, although a
battery plant worker might, for example, perform his
principal activities without donning proper protective
gear, he could not do so safely, see Steiner v. Mitchell, 350
U. S. 247, 250–253 (1956); likewise, a butcher might be
able to cut meat without having sharpened his knives, but
he could not do so effectively, see Mitchell v. King Packing
Co., 350 U. S. 260, 262–263 (1956); accord, 29 CFR
2      INTEGRITY STAFFING SOLUTIONS, INC. v. BUSK

                   SOTOMAYOR, J., concurring

§790.8(c). Here, by contrast, the security screenings were
not “integral and indispensable” to the employees’ other
principal activities in this sense. The screenings may, as
the Ninth Circuit observed below, have been in some way
related to the work that the employees performed in the
warehouse, see 713 F. 3d 525, 531 (2013), but the employ-
ees could skip the screenings altogether without the safety
or effectiveness of their principal activities being substan-
tially impaired, see ante, at 7.
   Second, the Court holds also that the screenings were
not themselves “ ‘principal . . . activities’ ” the employees
were “ ‘employed to perform.’ ” Ibid. (quoting 29 U. S. C.
§254(a)(1)). On this point, I understand the Court’s anal-
ysis to turn on its conclusion that undergoing security
screenings was not itself work of consequence that the
employees performed for their employer. See ante, at 7.
Again, I agree. As the statute’s use of the words “prelimi-
nary” and “postliminary” suggests, §254(a)(2), and as our
precedents make clear, the Portal-to-Portal Act of 1947 is
primarily concerned with defining the beginning and end
of the workday. See IBP, Inc. v. Alvarez, 546 U. S. 21,
34–37 (2005). It distinguishes between activities that are
essentially part of the ingress and egress process, on the
one hand, and activities that constitute the actual “work of
consequence performed for an employer,” on the other
hand. 29 CFR §790.8(a); see also ibid. (clarifying that a
principal activity need not predominate over other activi-
ties, and that an employee could be employed to perform
multiple principal activities). The security screenings at
issue here fall on the “preliminary . . . or postliminary”
side of this line. 29 U. S. C. §254(a)(2). The searches were
part of the process by which the employees egressed their
place of work, akin to checking in and out and waiting in
line to do so—activities that Congress clearly deemed to be
preliminary or postlimininary. See S. Rep. No. 48, 80th
Cong., 1st Sess., 47 (1947); 29 CFR §790.7(g). Indeed, as
                 Cite as: 574 U. S. ____ (2014)            3

                  SOTOMAYOR, J., concurring

the Court observes, the Department of Labor reached the
very same conclusion regarding similar security screen-
ings shortly after the Portal-to-Portal Act was adopted, see
ante, at 7–8, and we owe deference to that determination,
see Christensen v. Harris County, 529 U. S. 576, 587
(2000).
  Because I understand the Court’s opinion to be con-
sistent with the foregoing, I join it.
