                                                                   FILED
                                                       United States Court of Appeals
                              PUBLISH                          Tenth Circuit

                UNITED STATES COURT OF APPEALS                February 4, 2020

                                                          Christopher M. Wolpert
                      FOR THE TENTH CIRCUIT                   Clerk of Court
                  _________________________________

MARISELA AGUILAR; MIGUEL
BLANCO; FRANCISCO J. CARRANZA;
RAFAEL GALLEGOS; BENJAMIN
GUERRERO, JR.; VAUGHN D. HAYES,
SR.; JOSE R. HERNANDEZ; ROGELIO
HERNANDEZ; ROMAN JAUREGUI;
EFREN JIMENEZ; FLAVIO LARA;
SIXTO NAVARRETE; ANTHONY
GUADALUPE ORDAZ; ARMANDO                        No. 17-2198
PACHECO, JR.; ALAN PEREZ;
RIGOBERTO RODARTE; ANTONIO
VASQUEZ; ADRIAN VILLALOBOS,
a/k/a Jose Adrian Villalobos; MARIA
ACEVEDO; ANGEL AGUILAR;
EZEQUIEL ALVARADO; RICARDO
ANGULO; FERNANDO APODACA;
RENE ARREOLA; ANNETTE BAEZA;
JUAN BAEZA; REYMUNDO
BALDERRAMA; JUSTIN BARBA;
RAMON BAXTER; STEPHANIE
BERTOLLI; PEDRO BLANCO; DANIEL
BOADO; ANTHONY CALLA; LESLIE
CAMARILLO; YOLANDA CAMPOS;
STEFANY CARRANZA; JENNIFER
COOPER; EDWARD DANG; LUIS
DORADO; LUZ DUARTE; MIGUEL
DUENAS; JIM ESCALERA; HIRAM
ESCOBAR; JAIME ESCOBAR; MARTIN
L. ESPINOSA; CAROLINA ESTRADA;
GUADALUPE ESTRADA; CHRISTINE
FIERRO; JOSE FUENTES; MICHELLE
GALLEGOS; ALBERT GARCIA;
ANTHONY GARCIA; ARTURO
GARCIA; EDWARD GARCIA; CAESAR
GONZALEZ; JUAN GONZALEZ; RAUL
GUZMAN; DAVID HERNANDEZ;
JESUS HERNANDEZ; PAUL
HERNANDEZ; GINO HIJAR; JUN KOO;
ROCIO D. LEZA; CHRISTOPHER
MACIAS; ANGEL MALDONADO;
ARTURO MARES; DANIEL MARQUEZ;
PEDRO MARTINEZ; SAUL MARTINEZ;
YVONNE MARTINEZ; JUAN
MATAMOROS; YARETH MIRELES;
GABRIEL MOLINA; ARTURO
MONTERO; CARLOS MONTESINOS;
CECILIA MORALES; JESUS
MORALES; YVETTE MOREHEAD;
NORMA MUNIZ; SANDRA NERIA;
HERNAN NEVAREZ; ERICA NIETO;
ERIK ONTIVEROS; GARY LEE
OROZCO; LUIS ORTIZ; ROBERT
ORTIZ; DAVID PADILLA; JUAN
PARRA; VERONICA PENA; CARLOS
PONCE; JORGE PORTILLO; OSCAR
PORTILLO; JOSE I. PROSPERO; ISELA
QUEZADA; EDGAR RAMIREZ;
MIGUEL RAMIREZ; YGNACIO
RAMIREZ; GUSTAVO RAMON;
RODOLFO RINCON, SR.; RODOLFO
RINCON, JR.; ALBERTO RIVERA;
JENNIFER RIVERA; DANIEL
RODRIGUEZ; OSCAR RODRIGUEZ;
RUBEN RODRIGUEZ; VINCE ROMAN;
CARLOS ROSALES; ABEL SAENZ;
LILA SAENZ; BELINDA SANCHEZ;
DAVID SANCHEZ; ABRAHAM
SANDOVAL; GABRIELA SIFUENTES;
SALVADOR SIFUENTES; IRMA SOTO;
IRENE TERRAZAS-RUBIO; MANUEL
VASQUEZ; ADRIANA VILLALOBOS;
KARINA VILLALOBOS; SASHA
VILLALVA; MEAGAN VILLIGAN,

     Plaintiffs - Appellants,

v.

MANAGEMENT & TRAINING

                                2
 CORPORATION, d/b/a MTC,

       Defendant - Appellee.
                      _________________________________

                    Appeal from the United States District Court
                          for the District of New Mexico
                        (D.C. No. 2:16-CV-00050-WJ-GJF)
                      _________________________________

John P. Mobbs, El Paso, Texas, for Plaintiffs-Appellants.

Aaron C. Viets, Rodey, Dickason, Sloan, Akin & Robb, P.A., Albuquerque, New Mexico
(Charles J. Vigil, with him on the brief), for Defendant-Appellee.
                         _________________________________

Before BACHARACH, EBEL, and MORITZ, Circuit Judges.
                 _________________________________

MORITZ, Circuit Judge.
                    _________________________________

      A group of 122 detention officers (the officers) who work or worked at Otero

County Prison near Chaparral, New Mexico, allege that their employer, Management

& Training Corporation (MTC), fails to pay them for certain activities that they

engage in before they arrive at, when they arrive at, and after they leave their posts

within the prison. According to the officers, these activities constitute compensable

work, so MTC’s failure to pay violates both the Fair Labor Standards Act (FLSA) of

1938, 29 U.S.C. §§ 201–19, and the New Mexico Minimum Wage Act, N.M. Stat.

Ann. §§ 50-4-1 to 50-4-33.1


      1
         Below, the district court concluded that the officers “concede[d] that if
summary judgment was granted to their federal claims, it would also apply to the
state law claims.” App. vol. 5, 1184. The officers take a different position on appeal,
insisting that state and federal law treat compensability differently, such that even if
                                            3
       As explained below, we conclude that in this context, these activities

constitute compensable work. Further, we reject MTC’s arguments that (1) the time

the officers devote to these activities is de minimis and (2) it need not pay the

officers for these activities because it did not know the officers were engaging in

them. Additionally, we conclude that the officers’ rounding claim survives summary

judgment. As such, we reverse the district court’s order awarding summary judgment

to MTC and remand for further proceedings.

                                       Background

       The officers are “[r]esponsible for the custody and discipline of detainees.”

App. vol. 3, 573. Among other duties, the officers “[s]earch for contraband and

provide security”; “[c]ount, feed[,] and supervise detainees in housing, work[,] and

other areas”; and “prepare and maintain records, forms[,] and reports.” Id. The

officers generally work eight-hour shifts, five days a week. There are three shifts,

beginning at 6 a.m., 2 p.m., and 10 p.m. Each officer is typically assigned to work his

or her shift at a specific post, and there are more than 30 posts within the prison.

       Because this case concerns the activities that the officers engage in before they

arrive at and after they leave their posts, as well as one activity at post, we begin by

briefly outlining the officers’ undisputed daily routine. (We will later describe certain

of these activities in greater detail, as necessary to our analysis.)



their federal claims fail, their state claims survive summary judgment. Because we
ultimately find in the officers’ favor under federal law, we need not address the
officers’ argument on appeal or separately discuss their state-law claims.
                                             4
      When the officers arrive at the prison, they initially undergo a security

screening. Then—in what the parties characterize as a “pre[]shift briefing”—some

officers receive post assignments from a supervisor. App. vol. 5, 1158. During the

preshift briefing, officers sometimes receive paperwork or additional information

about their post for that day. Next, some officers obtain the keys they need for the

day’s post from a fingerprint-activated box. And some or most officers collect any

equipment they need for the day, such as handcuffs, a radio, or pepper spray, from

the prison’s inventory-control system. The officers then walk to their posts, where

they receive a “pass[]down briefing” from the officer leaving the post. Aplt. Br. 5.

After working their shifts, departing officers complete several of the same tasks in

reverse: they provide a passdown briefing to an incoming officer, walk back from

their post, and return their keys and equipment to the fingerprint-activated box and

the prison’s inventory-control system, respectively.2

      MTC requires the officers to use a time clock to precisely record their arrival

and departure times; officers clock in after undergoing the security screening and

clock out after returning their keys and equipment. Nevertheless, MTC generally

pays the officers based on their scheduled eight-hour shifts rather than on the precise

times at which they clock in and out. The one exception to this policy is the ten-

minute adjustment rule: if an officer clocks in or out more than ten minutes before or


      2
         The precise amount of time the officers devote to these activities is disputed.
The district court concluded that the officers devote no more than eight minutes per
shift to completing these activities; the officers contend that the time exceeds ten
minutes per day. But as we explain later, this dispute is not material to our analysis.
                                           5
after his or her shift start or end time, MTC will pay the officer based on the time

clock rather than on his or her scheduled shift. That is, if an officer clocks in for a 6

a.m. shift at 5:58 a.m. and clocks out at 2:09 p.m., MTC will pay that officer for the

eight-hour shift (i.e., from 6:00 a.m. to 2:00 p.m.); but if an officer clocks in for that

same shift at 5:45 a.m. and clocks out at 1:49 p.m., MTC will pay that officer based

on the time clock (i.e., for eight hours and four minutes). This rule applies on either

end of the shift time, so that if an officer clocks in at 5:49 a.m. and clocks out at 1:56

p.m., MTC will pay that officer for time worked from 5:49 a.m., the clock-in time, to

2 p.m., the shift-end time (i.e., for eight hours and 11 minutes). In addition, MTC

provides officers with time-adjustment forms, which the officers can complete to

request payment if they devote time outside of their scheduled shift to compensable

work.

        The officers contend that MTC’s compensation system deprives them of

overtime pay in two ways. First, they allege that because MTC typically pays them

based on shift time rather than clock time, it fails to pay them for the time they

devote to undergoing the security screening, receiving the preshift briefing, checking

keys and equipment in and out, walking to and from post, and conducting passdown

briefings. Second, the officers allege that MTC’s ten-minute adjustment rule

routinely rounds down their work time, resulting in systematic underpayment.

        Following discovery, MTC moved for summary judgment. It argued that

officers do not perform compensable work under the FLSA when they undergo the

security screening, receive the preshift briefing, check keys and equipment in and

                                             6
out, walk to and from post, and conduct passdown briefings. Further, MTC

alternatively argued that if any of that time was compensable, it was de minimis and

thus not recoverable. See 29 C.F.R. § 785.47 (providing that “insubstantial or

insignificant periods of time beyond the scheduled working hours, which cannot as a

practical administrative matter be precisely recorded for payroll purposes, may be

disregarded”). MTC additionally (1) insisted that it did not impermissibly round off

the officers’ working time and (2) raised an estoppel defense, arguing that it need not

pay the officers because it did not know the officers were engaging in these activities.

      The district court ruled that of the activities the officers described, only the

passdown briefing was integral and indispensable to the officers’ principal activities

and therefore compensable. But the district court ultimately concluded the officers

were not entitled to compensation for the time devoted to conducting passdown

briefings because that time was de minimis. It further rejected the officers’ rounding

claim. As such, the district court granted MTC summary judgment on all of the

officers’ claims (without reaching MTC’s estoppel defense). The officers appeal.

                                       Analysis

      “We review the district court’s summary[-]judgment decision de novo,

applying the same standards as the district court.” Punt v. Kelly Servs., 862 F.3d

1040, 1046 (10th Cir. 2017). “Under these standards, ‘[s]ummary judgment is proper

if, viewing the evidence in the light most favorable to the non[]moving party, there is

no genuine dispute as to any material fact and the movant is entitled to judgment as a



                                            7
matter of law.’” Id. (first alteration in original) (quoting Peterson v. Martinez, 707

F.3d 1197, 1207 (10th Cir. 2013)).

I.    Compensable Work

      The FLSA requires an employer to pay employees for their work, but it does

not define what kinds of activities qualify as compensable work. See 29 U.S.C.

§§ 206–07; Integrity Staffing Sols., Inc. v. Busk, 574 U.S. 27, 31 (2014). Confronting

that absence, the Supreme Court initially defined compensable work as “all time

during which an employee is necessarily required to be on the employer’s premises,

on duty or at a prescribed workplace.” Busk, 574 U.S. at 31 (quoting Anderson v. Mt.

Clemens Pottery Co., 328 U.S. 680, 690–691 (1946)). But Congress narrowed that

definition when it enacted the Portal-to-Portal Act of 1947, 29 U.S.C. §§ 251–62,

which carves out two exclusions from the FLSA’s definition of compensable work.

See Busk, 574 U.S. at 32–33. First, the Act provides that the time an employee

devotes to “walking, riding, or traveling to and from the actual place of performance

of the principal activity or activities which such employee is employed to perform” is

not compensable. 29 U.S.C. § 254(a)(1). Second, the Act provides that the time

devoted to “activities which are preliminary to or postliminary to [the employee’s]

principal activity or activities” is not compensable. § 254(a)(2).

      Determining whether an activity is “preliminary to or postliminary to . . . [a]

principal activity or activities” requires deciding what constitutes an employee’s

“principal activity or activities.” Id. Courts have defined this phrase to include both

the principal activities themselves and “all activities which are an ‘integral and

                                            8
indispensable part of the principal activities.’” Busk, 574 U.S. at 33 (quoting IBP,

Inc. v. Alvarez, 546 U.S. 21, 29–30 (2005)); see also 29 C.F.R. § 790.8(b), (c). In

turn, an activity is “integral and indispensable . . . if it is an intrinsic element of those

[principal] activities and one with which the employee cannot dispense if [the

employee] is to perform his [or her] principal activities.” Busk, 574 U.S. at 33.

Critically, the integral-and-indispensable inquiry does not turn on whether the

employer requires the activity or whether the activity benefits the employer.3 Id. at

36. Instead, the question is “tied to the productive work that the employee is

employed to perform.” Id.

       Here, the parties agree that the officers’ principal activities include

maintaining “the custody and discipline of inmates,” “supervising detainees,”

“searching for contraband[,] and providing security.” App. vol. 3, 446. But the

officers argue that the district court erred when it concluded that the officers’

activities before they reach their posts and after they leave their posts are



       3
        Before the Supreme Court decided Busk, courts routinely decided the
integral-and-indispensable issue by asking these two questions: whether the employer
required the activity or whether the activity benefited the employer. See, e.g., Whelan
Sec. Co. v. United States, 7 Cl. Ct. 496, 498–99 (1985). But the Busk court
specifically rejected those approaches as “overbroad.” Busk, 574 U.S. at 36.
Accordingly, Busk effected a change in the law. Thus, to the extent a pre-Busk case
turned on these now-disapproved rationales, its analysis of the integral-and-
indispensable issue is inapposite. See Bridges v. Empire Scaffold, L.L.C., 875 F.3d
222, 227–28 (5th Cir. 2017) (rejecting reliance on pre-Busk cases whose rationales
were no longer applicable). However, to the extent that a pre-Busk case did not turn
on these now-disapproved rationales, it remains on point. So, throughout this
opinion, we disclaim reliance on pre-Busk cases that turned on these now-
disapproved rationales but continue to rely on pre-Busk cases that did not.
                                              9
noncompensable preliminary and postliminary activities that are not integral or

indispensable to these principal activities. For the reasons explained below, we

conclude that all these activities—undergoing the security screening, receiving the

preshift briefing, picking up and returning keys and equipment, and walking to and

from post—are integral and indispensable to the officers’ principal activities.4

      A.     Preshift Activities5

      We begin with the first activity of the officers’ day: the security screening.

During the security screening—which occupies between three and eleven minutes—

the officers empty their pockets, remove their jackets and all metal, sometimes

remove their boots, present any briefcases, lunchboxes, or bags for inspection, and

walk through a metal detector before reclaiming their possessions. MTC requires and

conducts the security screening to ensure “the overall safety of the prison” and to

prevent officers from inadvertently or intentionally bringing contraband like weapons

or cell phones into the prison. App. vol. 3, 559.

      The district court determined that the screening was “a preliminary security

measure” that was not integral or indispensable to the officers’ principal activities.

App. vol. 5, 1158. In reaching this conclusion, the district court relied on Busk, in



      4
         We also conclude, albeit for a different reason than the district court did, that
the one activity occurring at post, the passdown briefing, is integral and
indispensable to the officers’ principal activities.
       5
         For ease of reference, we refer to the security screening, preshift briefing,
key and equipment pickup, walk to post, and preshift passdown briefing as “preshift
activities.” Likewise, we refer to the postshift passdown briefing, walk back from
post, and key and equipment return as “postshift activities.”
                                            10
which the Supreme Court held that a postshift security screening was not

compensable under the FLSA. See 574 U.S. at 36. Busk involved warehouse

employees whose job functions included “retriev[ing] products from warehouse

shelves and packag[ing] those products for shipment.” Id. at 35. To deter theft, the

employer required the employees to undergo a postshift security screening. Id. The

Supreme Court held that the screening was not compensable work because it was not

integral or indispensable to the employees’ principal activity of retrieving and

packaging items from warehouse shelves. Id. In fact, the employer “could have

eliminated the screenings altogether without impairing the employees’ ability to

complete their work.” Id.

      But as the officers point out, Busk did not hold that a security screening can

never be compensable. Instead, the Court explained that whether an activity is

compensable depends on “the productive work that the employee is employed to

perform.” Id. at 36. And that “productive work” marks the critical distinction

between Busk and this case. Id. There, the theft-prevention, postshift security

screening was not “tied to” the work of retrieving items from warehouse shelves. Id.

Indeed, there was no connection at all between the work and the screening.

      We cannot say the same here. MTC conducts the security screening to prevent

weapons and other contraband from entering the prison. And keeping weapons and

other contraband out of the prison is necessarily “tied to” the officers’ work of

providing prison security and searching for contraband. Id. Indeed, the security

screening and the officers’ work share the same purpose.

                                           11
       MTC resists this connection, encouraging us to adopt the district court’s

reliance on Busk’s suggestion that neither “searches conducted for the safety of the

employees [nor] those conducted for the purpose of preventing theft” were integral or

indispensable. Id. This statement in Busk concerned an opinion letter issued by the

Department of Labor in 1951. Id. at 35. The Department’s letter explained that for

employees in a rocket-powder plant, neither a preshift search aimed at preventing

matches and cigarette lighters from entering the plant nor a postshift search aimed at

preventing theft was compensable. Id. So, the Busk court reasoned, the Department

drew no distinction between searches for employee safety and searches to prevent

theft. Id. at 35–36.

       But the Department based its opinion letter on significantly different

circumstances than those presented here. The screenings here are obviously not

aimed at preventing theft. Neither are they necessarily analogous to the safety

searches at the rocket-powder plant. And notably, neither the Department’s opinion

letter nor the Court in Busk clearly outlined the principal activities of the employees

at the rocket-powder plant. But the Busk Court explained that the plant’s preshift

search was aimed at “the safety of employees.” Id. Standing on its own, an

employer’s general desire to keep its employees safe has no clear or obvious

connection to the particular activities those employees are employed to perform.

Here, by contrast, the officers’ principal duties include “searching for contraband and

providing security.” App. vol. 3, 446. So even if this security screening relates in part

to overall prison safety, what matters is that the screening is “tied to” the productive

                                           12
work that MTC employs the officers to perform, rendering it integral and

indispensable to those duties.6 Busk, 574 U.S. at 36.

      Moreover, unlike the employer in Busk, MTC could not “have eliminated the

screenings altogether without impairing the employees’ ability to complete their

work.” Id. at 35; see also id. at 37–38 (Sotomayor, J., concurring) (explaining that

the question is whether employees “could not dispense with [the security screening]

without impairing [their] ability to perform the[ir] principal activit[ies] safely and

effectively”). Arguing against this conclusion, MTC contends that an officer “can

obviously maintain custody and discipline of inmates whether or not the officer

walked through a metal detector earlier.” Aplee. Br. 17. But indispensability does not

depend upon whether the officers could perform some aspect of their jobs in the

absence of the activity; the question is whether the employer “could have eliminated

the screenings altogether without impairing the employees’ ability to complete their

work,” Busk, 574 U.S. at 35; see also id. at 37–38 (Sotomayor, J., concurring).




      6
         MTC also urges us to adopt the district court’s distinction between
“searching for contraband” and “being searched for contraband.” App. vol. 5, 1157.
But we find this distinction immaterial. Both “searching for” and “being searched
for” contraband involve keeping contraband out of the prison and maintaining a
secure prison environment. Id. Moreover, if MTC means to suggest that the officers
are not performing work simply because they are passively undergoing screening
rather than actively performing some duty, we reject that suggestion as well. The
Court could have relied on such a distinction in Busk, but it did not—likely because
such a distinction simply is not relevant to the integral-and-indispensable issue.
Indeed, exertion typically is not part of the compensability analysis. See Alvarez, 546
U.S. at 25.
                                           13
       Here, if MTC were to forego officer screening, officers could inadvertently or

intentionally bring weapons or other contraband into the prison. The introduction of

weapons or other contraband into the prison would most certainly result in a less

secure prison. But more importantly, it would “impair[]” the officers’ ability to

provide security and search for contraband, id. at 35, as well as their ability to do so

“safely and effectively,” id. at 37–38 (Sotomayor, J., concurring); see also Steiner v.

Mitchell, 350 U.S. 247, 249–53, 255–56 (1956) (holding that time spent changing

clothes and showering was compensable because without doing so, battery-plant

workers could not safely perform principal activity of producing batteries in highly

toxic environment); Mitchell v. King Packing Co., 350 U.S. 260, 262–63 (1956)

(holding that time spent sharpening knives was compensable because butchers could

not effectively cut meat without sharpening). Stated more plainly, an officer cannot

safely and effectively maintain “custody and discipline of inmates” and “provid[e]

security” while also bringing weapons or contraband into the prison. App. vol. 3,

446; see also Busk, 574 U.S. at 37–38 (Sotomayor, J., concurring). The security

screening in this case is therefore indispensable to the officers’ principal activities.

       Additionally, preventing weapons or other contraband from entering the

prison, by way of the security screening, is “an intrinsic element of” the officers’

security work. Busk, 574 U.S. at 33. Again, the security screening and the officers’

work share the same goal: maintaining a secure prison environment by preventing

contraband from inadvertently or intentionally entering the prison. Thus, under these

factual circumstances, we conclude that the screening is an integral part of what

                                            14
MTC employed the officers to do. See id. And because the screening is both integral

and indispensable to the officers’ principal activities, the district court erred in ruling

otherwise and in granting summary judgment to the officers on this issue.

       Because the time the officers devote to undergoing the security screening is

integral and indispensable to their principal activities, that activity begins their

workday. See id. at 33 (defining principal activities to include those activities that are

integral and indispensable to principal activities); Alvarez, 546 U.S. at 28 (noting that

workday begins with commencement of principal activities). And under the

continuous-workday rule, “[o]nce the work[]day starts, all activity is ordinarily

compensable until the work[]day ends.” Castaneda v. JBS USA, LLC, 819 F.3d 1237,

1243 (10th Cir. 2016); see also 29 C.F.R. § 790.6(a) (providing that Portal-to-Portal

Act does not apply to activities performed “after the employee commences to

perform the first principal activity on a particular workday and before [the employee]

ceases the performance of the last principal activity on a particular workday”). Thus,

we further hold that the time the officers devote to receiving the preshift briefing,

picking up keys and equipment, walking to post, and conducting the preshift

passdown briefing is also compensable under the FLSA.

       B.     Postshift Activities

       Because the continuous-workday rule makes compensable all activities that

occur from the moment that “the work[]day starts . . . until the work[]day ends,”

Castaneda, 819 F.3d at 1243, we begin our postshift analysis with the last activity of



                                            15
the officers’ day: returning keys and equipment. If that activity is compensable, then

so is the walk from post and the postshift passdown briefing. See id.

      Not every officer returns keys and equipment, but many do. The district court

found that “the number of officers who pick up equipment at central control [and

therefore must return it] varies from less than 50% . . . to less than 83%.” App. vol. 5,

1162. The keys are stored in a fingerprint-activated box, and MTC maintains a key

log indicating who possesses each key and when the keys are checked in and out.

Access to the equipment is similarly controlled; officers use “individualized metal

coins, called ‘chits’” to record who checks particular pieces of equipment in and out.

App. vol. 3, 957. Importantly, these processes help ensure that inmates do not obtain

possession of keys or equipment and thus are necessary to maintain the security of

the prison.

      The district court found that the keys and equipment were “to be sure, useful

and helpful to the officers in doing their jobs.” App. vol. 5, 1168. In particular, the

district court specifically noted that the officers “use keys to guard the inmates and to

lock and unlock doors to ensure security”; “use radios to communicate with officers

at their posts and to give them directions and instructions throughout the day”; and

use “[h]and restraints and pepper spray . . . as both a deterrent and if necessary, to

control unruly inmates.” Id. at 1164. Based on these findings, we have little difficulty

concluding that picking up and returning the keys and equipment is indispensable to

the officers’ ability to perform their work. If MTC were to eliminate the keys and

equipment (or the corresponding inventory-control systems), the officers’ ability to

                                           16
maintain custody and discipline of inmates and provide security in the prison would

be “impair[ed].” Busk, 574 U.S. at 35; see also id. at 37–38 (Sotomayor, J.,

concurring). Indeed, an officer “cannot dispense” with the keys and equipment “if

[the officer] is to perform his [or her] principal activities” of maintaining custody and

discipline of inmates and providing security. Id. at 37.

       Despite this indispensability, the district court concluded that picking up and

returning keys and equipment was not “an ‘intrinsic element’ of the officers’

principal activities.” App. vol. 5, 1168 (quoting Busk, 574 U.S. at 35). The district

court began its analysis by distinguishing or rejecting each of the cases that the

officers cited in support of finding compensability. In so doing, it emphasized that

“the type of tools and equipment carried by the officers are small in size and not

burdensome to carry.” Id. Then, without additional analysis, the district court

concluded that although “certain pre[]shift activities are necessary for employees to

engage in their principal activities,” that fact “does not mean that those preshift

activities are ‘integral and indispensable’ to a ‘principal activity.’” Id. (quoting

Alvarez, 546 U.S. at 40).

       On appeal, the officers argue that checking keys and equipment in and out is

integral and indispensable to their principal activities. In support, they first cite a

variety of cases in which courts have held that picking up equipment is a

compensable activity. See Von Friewalde v. Boeing Aerospace Operations, Inc., 339

F. App’x 448, 454–55 (5th Cir. 2009) (unpublished); Whelan Sec., 7 Cl. Ct. at 498–

99; Baylor v. United States, 198 Ct. Cl. 331, 357–58 (1972); U.S. Dep’t of Justice v.

                                            17
Am. Fed’n of Gov’t Emps. Local 919, 59 F.L.R.A. 593, 597–98 (2004). But each of

these cases was decided before the Busk Court refined the integral-and-indispensable

test by rejecting formulations of this test that turn solely on whether “an employer

required a particular activity” or “whether the activity is for the benefit of the

employer.” 574 U.S. at 36. And each of these cases turn specifically on one or both

rejected rationales. See Von Friewalde, 339 F. App’x at 454–55 (finding that

“checking specialized tools in and out of the tool crib” was compensable activity for

airplane mechanics because it was for employer’s benefit); Whelan Sec., 7 Cl. Ct. at

498–99 (finding time that security guards spent picking up weapons was

compensable because it was for employer’s benefit); Baylor, 198 Ct. Cl. at 357–58

(same); Am. Fed’n of Gov’t Emps., 59 F.L.R.A. at 597–98 (finding that time federal

correctional officers spent picking up keys and equipment was compensable because

employer required such activities). Thus, we do not rely on these cases because their

reasoning does not survive Busk. See Bridges, 875 F.3d at 227–28; supra, note 3.

       But the officers’ argument extends beyond these superseded cases. The

officers contend that “when an employee must pick up specialized equipment from

his [or her] employer to perform his [or her] duties, that [activity] is part of his [or

her] principal work activity.” Aplt. Br. 34 (emphasis added). In support, they rely on

Brantley v. Ferrell Electric, Inc., 112 F. Supp. 3d 1348 (S.D. Ga. 2015), and

Alvarado v. Skelton, No. 3:16-3030, 2017 WL 2880396 (M.D. Tenn. July 6, 2017)

(unpublished). In Brantley, the district court held that “collecting and loading the

specific parts necessary to complete” electrical work was “intrinsic in installing,

                                            18
servicing, and repairing electrical equipment.” 112 F. Supp. 3d at 1371. And in

Alvarado, the district court found that time spent picking up and loading required

landscaping tools and equipment onto work trucks triggered the start of the workday

for landscaping employees. See 2017 WL 2880396, at *5.

      Here, as in Brantley and Alvarado, the close connection between (1) the keys

and equipment and (2) the nature of the officers’ work convinces us that checking out

and returning these items is “an intrinsic element” of providing security in the prison.

Busk, 574 U.S. at 37; see also Peterson v. Nelnet Diversified Sols., LLC, 400 F. Supp.

3d 1122, 1135 (D. Colo.) (“Court[s] have long held that pre[]shift preparation of

tools or equipment is considered integral and indispensable to the principal activities

when the use of such tools in a readied or activated state is an integral part of the

performance of the employee’s principal activities.”), appeal docketed, No. 19-1348

(10th Cir. Sept. 17, 2019). In particular, we note that the specialized nature of the

keys and equipment ties the act of picking them up and returning them more closely

to the officers’ productive work. See D A & S Oil Well Servicing, Inc. v. Mitchell,

262 F.2d 552, 554–55 (10th Cir. 1958) (“[E]mployees who transport equipment

without which well servicing could not be done[] are performing an activity which is

so closely related to the work which they and the other employees perform[] that it

must be considered an integral and indispensable part of their principal activities.”);

cf. Smith v. Aztec Well Servicing, Inc., 462 F.3d 1274, 1289 (10th Cir. 2006) (finding

that activity of putting personal, nonspecialized equipment into van was not

compensable activity).

                                           19
      Moreover, the specialized nature of the keys and equipment in this case is

further reinforced by the mandatory procedures that each officer must comply with

when obtaining or returning keys and equipment. Recall that in the interest of overall

prison safety, the keys are stored in a fingerprint-activated box, and MTC maintains a

log of when each key is checked out, who checks it out, and when it is returned.

Further, in order to check in or out particular pieces of equipment, officers must use

individualized metal coins—or “chits”—that record who possesses the equipment.

App. vol. 5, 957.

      Not only does this inventory-control system emphasize the specialized nature

of keys and equipment in the prison context, it further buttresses our conclusion that

the process of checking the keys and equipment in and out is intrinsic to the officers’

principal activities of maintaining custody and discipline of inmates and providing

security. Similar to the security screening, the inventory controls exist to ensure the

overall safety of the prison environment. Indeed, “inmates are never allowed access

to keys for security reasons,” and the equipment-monitoring system exists “to

monitor the equipment and make sure it does not get into the hands of inmates.” App.

vol. 5, 956–57. So the keys and equipment are not just necessary to the officers’

work—the time devoted to checking those items in and out of the inventory-control

systems is also closely aligned with their principal activities of maintaining custody

and discipline of inmates and providing security. Cf. Peterson, 400 F. Supp. 3d at

1130 (noting that “activities which are necessary to perform one’s work but not



                                           20
substantively connected to the actual performance of such work are not considered

compensable”).

       Not to be deterred, MTC argues that we should find this activity not

compensable based on the distinction the district court drew between the easy-to-

carry keys and equipment at issue here and the heavy and burdensome equipment at

issue in cases like Brantley and D A & S Oil Well Servicing. But exertion is not

typically considered as part of the compensability analysis. See Alvarez, 546 U.S. at

25 (noting that “‘exertion’ [i]s not in fact necessary for an activity to constitute

‘work’ under the FLSA” (quoting Armour & Co. v. Wantock, 323 U.S. 126, 132

(1944))). Nevertheless, MTC argues “the case[]law suggests that the simpler, faster,

and easier it is to get and carry the items, the more likely these actions are to be

preliminary” and not compensable. See, e.g., D A & S, 262 F.2d at 555 n.5 (citing

with approval regulation that distinguished between carrying power saw versus

carrying “ordinary hand tools”); Clay v. Huntington Ingalls, Inc., No. 09-7625, 2011

WL 13205917, at *10 (E.D. La. Sept. 29, 2011) (unpublished) (“[T]he act of merely

retrieving and toting a pair of pliers and a screwdriver is not going to trigger the start

of the continuous workday.”).

       But MTC’s argument overlooks the distinct circumstances of this case:

although the keys and equipment may be easy to carry, they are not simple or easy to

obtain; officers must collect the keys from a fingerprint-protected box, check the

equipment out using chits, and maintain responsibility for those items until they are

checked back in at the end of the shift. And perhaps more importantly, this easy-

                                            21
versus-burdensome distinction is not particularly helpful in determining the

connection between the tools and the work the officers are employed to perform. See

Busk, 574 U.S. at 36 (noting that integral-and-indispensable question turns on

whether activity “is tied to” work employee performs); D A & S Oil Servicing, 262

F.2d at 555 (noting that transporting tools was integral and indispensable because

tools were “closely related” to work performed).

      We thus decline MTC’s implicit invitation to stray from the Supreme Court’s

direction in Busk. That direction requires us to determine whether an activity is

integral and indispensable by considering how closely the activity “is tied to the

[employee’s] productive work.” 574 U.S. at 36. Generic tools and equipment like

screwdrivers and paperwork are common to a variety of jobs and therefore play no

specialized role in most types of work, no matter how necessary they might be to a

particular job. But items like handcuffs, pepper spray, and prison-door keys are

closely connected to the work of providing prison security.

      Indeed, the district court specifically noted that some of the officers’ “essential

functions” were to “[t]ransfer and transport detainees”; “[r]estrain and secure

assaultive detainees”; and “perform use of force procedures, including the use of

chemical agents to control detainees.” App. vol. 5, 1168. It seems obvious that an

officer could not effectively complete these “essential functions” if the officer had

not checked out the keys needed to move a detainee, the handcuffs needed to restrain

or secure a detainee, or the pepper spray used to control a detainee. Id.; see also King

Packing Co., 350 U.S. at 262 (holding that time butchers spent sharpening knives

                                           22
was compensable because dull knives would “slow down production,” affect meat

quality, and lead to “accidents”). Further, the inventory-control system from which

the officers obtain the keys and equipment is essential to the officers’ principal

activities of providing prison security because it prevents inmates’ access to the keys

and equipment.

       As such, because of the specialized nature of the keys and equipment, the

inventory-control systems, and the officers’ principal activities in the prison

environment, we hold that checking keys and equipment in and out of the prison’s

inventory-control systems is integral and indispensable to the officers’ principal

activities of maintaining custody and discipline of the inmates and providing security.

See Busk, 574 U.S. at 37. And because returning the keys and equipment is the last

principal activity in the officers’ workday, the postshift activities that take place

before that—the postshift passdown briefing and walking back from post—are also

compensable. See Castaneda, 819 F.3d at 1243. Thus, the district court erred in

granting summary judgment to MTC on this issue.

II.    De Minimis Doctrine

       We next consider whether the amount of time that the officers devote to these

compensable pre- and postshift activities is de minimis and therefore not

compensable. But before undertaking this analysis, we pause to note that MTC’s

briefing on the de minimis issue assumes that only the passdown briefings are

compensable. As such, MTC never makes the argument necessarily presented by our

conclusion that all the pre- and postshift activities are compensable: that the de

                                            23
minimis doctrine applies even in these circumstances. Accordingly, because MTC did

not address this argument in its prinicpal brief, we could decline to consider the de

minimis doctrine at all. See Bronson v. Swensen, 500 F.3d 1099, 1104 (10th Cir.

2007). Yet assuming MTC did make such an argument, we reject it on the merits for

the reasons explained below. See Kellar v. Summit Seating Inc., 664 F.3d 169, 176

(7th Cir. 2011) (noting that employer bears the burden of establishing that de minimis

doctrine applies).

      The de minimis doctrine provides that “insubstantial or insignificant periods of

time beyond the scheduled working hours, which cannot as a practical administrative

matter be precisely recorded for payroll purposes, may be disregarded.” § 785.47. At

the same time, “[a]n employer may not arbitrarily fail to count as hours worked any

part, however small, of the employee’s fixed or regular working time or practically

ascertainable period of time [the employee] is regularly required to spend on duties

assigned to [the employee].” Id. The de minimis doctrine applies to “the amount of

daily time spent on the additional work.” Reich v. Monfort, 144 F.3d 1329, 1333

(10th Cir. 1998) (emphasis added) (quoting Lindow v. United States, 738 F.2d 1057,

1062 (9th Cir. 1984)); see also Hootselle v. Mo. Dep’t of Corrs., No. WD 82229,

2019 WL 4935933, at *4 & n.6 (Mo. Ct. App. Oct. 8, 2019) (aggregating, for

purposes of de minimis analysis, time devoted to compensable pre- and postshift

activities). We apply a three-factor test to determine whether work time is de minimis

and therefore not compensable: “(1) the practical administrative difficulty of

recording the additional time; (2) the size of the claim in the aggregate; and

                                           24
(3) whether the [employees] performed the work on a regular basis.” Castaneda, 819

F.3d at 1243 (quoting Monfort, 144 F.3d at 1333–34).

       Before applying the three factors, we must first estimate the amount of time at

issue. Monfort, 144 F.3d at 1333 n.1. “There is no precise amount of time that may be

denied compensation as de minimis.” Id. at 1333. And we have approvingly cited

cases finding that “as little as ten minutes of working time goes beyond the level of

de minimis.” Id. (quoting Reich v. IBP, Inc., 38 F.3d 1123, 1126 (10th Cir. 1994)).

       Here, the amount of time that officers spend daily on compensable pre-and

post-shift activities is not entirely clear. The district court concluded that the amount

of time was “substantially less than . . . eight minutes per shift.” App. vol. 5, 1181.

The district court appears to have derived that number from the parties’ summary-

judgment briefing: MTC calculated eight minutes per shift as the most favorable

number for the officers, and the officers likewise estimated eight minutes per shift

(although they elsewhere argued that the amount of time was more than ten minutes).

Because the district court concluded that only the passdown briefing was

compensable, it accordingly found that the time was “substantially less than . . . eight

minutes per shift.” Id. (emphasis added). But because we have concluded that all of

the officers’ pre- and postshift activities are compensable, we assume that the amount

of time is at least eight minutes per shift.7


       7
         Indeed, it is likely more than eight minutes per shift. As MTC acknowledges,
its ten-minute adjustment rule is based on the approximate amount of time it takes to
get from the time clock—immediately following the security screening—to the posts.
And because those ten minutes occur at both ends of an officer’s shift, the amount of
                                             25
         The first de minimis factor, “the practical administrative difficulty of

recording the additional time,” weighs in the officers’ favor—the time clock already

tracks most of the time at issue.8 Monfort, 144 F.3d at 1334 (quoting Reich v. N.Y.C.

Transit Auth., 45 F.3d 646, 652 (2d Cir. 1995)). The time clock is located just past

the metal detector and captures all of the compensable activities except the screening

itself. Further, it is possible to estimate the average time the officers devote to

screening. See Kellar, 664 F.3d at 176–77 (noting that because employees performed

the same activities every day, “it would have been possible to compute how much

time” employee spent on them); Rutti v. Lojack Corp., Inc., 596 F.3d 1046, 1059 (9th

Cir. 2010) (noting that even though “it may be difficult to determine the actual time”

at issue, “it may be possible to reasonably determine or estimate the average time”).

Thus, because MTC already records the majority of the time at issue and could

reasonably estimate the time that it does not record, this factor weighs in the officers’

favor.

         Next, “the aggregate amount of compensable time”—a factor that considers

both the aggregate claim for each individual officer as well as the aggregate claim for

all the officers combined—also weighs in the officers’ favor. Monfort, 144 F.3d at



time could be as much as 20 minutes. (It is likely not more than 20 minutes because
if an officer works more than ten additional minutes on either end of a shift, MTC
pays him or her for that time under the ten-minute adjustment rule.)
       8
         The district court found otherwise, but that is because it considered only the
passdown briefing. We reach a different conclusion on this factor because we
consider all of the officers’ compensable activities, beginning with the security
screening and ending with the return of keys and equipment.
                                             26
1334. The district court did not make an express finding about the aggregate amount

of compensable time; instead, it concluded that the aggregate claim for all the

officers combined was substantially less than the amount that MTC provided in its

summary-judgment motion, $355,478, because that number included compensation

for time devoted to noncompensable activities.9 The district court then weighed that

finding in MTC’s favor because a number less than $355,478 was substantially less

than the $1.6 million that we weighed in the plaintiffs’ favor in Monfort.

      But we cannot rely upon the district court’s less-than-$355,478 conclusion

because that conclusion turned on the underlying determination that only the

passdown briefing was compensable. Because we have concluded that all of the

officers’ pre- and postshift activities are compensable, we assume that the aggregate

claim is at least $355,478.10

      And more importantly, the district court erred in treating Monfort as if it set a

baseline below which all claims are negligible; rather, the court there merely noted


      9
         MTC calculated this amount based on an officer who worked eight additional
overtime minutes per shift, five days a week, for three years, and then multiplied that
figure by 122 plaintiffs.
       10
          Indeed, as with the amount of time at issue, the aggregate claim could be
higher. On appeal, the officers provide a higher per-officer claim estimate “[b]ased
on a representative sample of 15% of the officers” over “the four-year time period
covered by this suit.” Aplt. Br. 56. According to the officers, each officer’s back-pay
claim for this four-year time period averages $7,093.28. Although the officers do not
provide an estimated aggregate amount in their briefing, multiplying their per-officer
estimate by 122 plaintiffs results in an estimated total aggregate claim of
$865,380.16. We need not accept this estimate to complete our analysis here. But we
acknowledge it in order to emphasize both that (1) we base our de minimis analysis
on assumptions and estimates, rather than definitive numbers, and (2) those
assumptions and estimates are arguably conservative.
                                          27
that a $1.6 million claim “was very large.” Monfort, 144 F.3d at 1334. In fact, more

moderately sized claims are not automatically negligible. See Perez v. Mountaire

Farms, Inc., 650 F.3d 350, 374 (4th Cir. 2011) (noting that in case involving 280

employees, individual claims for $425 per year or $2,550 over six years were

“significant”); Lindow, 738 F.2d at 1063 (suggesting $1 per week for 50 weeks

would not be de minimis claim). Indeed, MTC cites no cases in which a court

weighed a claim of this size in the employer’s favor. Thus, we conclude that the

aggregate size of the officers’ claims is substantial and weighs in their favor.

       As to the third factor, we conclude that the regularity with which the officers

perform this work also favors the officers. See Monfort, 144 F.3d at 1334. The

district court found that this factor balanced equally between the parties because

(1) “[i]t is apparent that all officers receive pass[]down briefing[s],” but (2) “there is

no fixed time any of them must show up on post for these briefings.” App. vol. 5,

1182. We, of course, look at more than just the passdown briefings. And it seems

clear that most officers perform most of these activities during most shifts. Indeed,

MTC requires both the security screening and the passdown briefings, and it designed

the ten-minute adjustment rule to account for the time it takes to get from the security

screening to post. See Monfort, 144 F.3d at 1334 (weighing regularity factor in

employees’ favor where activities took about ten minutes each day); Jimenez v. Bd. of

Cty. Comm’rs of Hidalgo Cty., 697 F. App’x 597, 599 (10th Cir. 2017) (unpublished)

(rejecting de minimis doctrine for required five-minute briefing period because time

was regular and ascertainable). As such, we weigh this factor in the officers’ favor.

                                            28
       In sum, and contrary to the district court’s conclusions, all three factors weigh

in favor of the officers: MTC already records most of the time at issue, the aggregate

claim is substantial, and the officers regularly engage in these activities. As such, we

find that the time at issue is not de minimis and conclude that the district court erred

in granting summary judgment to MTC on this basis. See Monfort, 144 F.3d at 1334

(finding that time was not de minimis based on size of claim and regularity of work

and despite administrative difficulty of recording time).

III.   Suffer or Permit to Work

       Next, MTC argues that even if the officers’ activities are compensable, the

officers should not be allowed to claim compensation for them because MTC did not

know that the officers were doing this work. The district court did not reach this

argument because it ruled against the officers on compensability. But we have

reached the opposite conclusion. Thus, we address—but ultimately reject—MTC’s

position that it need not compensate the officers because it did not know the officers

were engaging in this work.

       The FLSA requires employers to pay employees when the employers “suffer or

permit [employees] to work.” 29 U.S.C. § 203(g); see also Mencia v. Allred, 808

F.3d 463, 470 (10th Cir. 2015). This provision creates a kind of FLSA estoppel

doctrine: if an employer does not know that an employee is doing certain work, then

the employer is not required to pay the employee for that work. See Mencia, 808 F.3d

at 470. But if the employer is aware of the work and therefore “suffer[s] or permit[s]”

the work, it must pay the employee. § 203(g); see also Mencia, 808 F.3d at 470.

                                           29
Stated differently, “[a]n employer who is armed with [knowledge that an employee is

working overtime] cannot stand idly by and allow an employee to perform overtime

work without proper compensation, even if the employee does not make a claim for

the overtime compensation.” Fairchild v. All Am. Check Cashing, Inc., 815 F.3d 959,

964 (5th Cir. 2016) (second alteration in original) (quoting Harvill v. Westward

Commc’ns, L.L.C., 433 F.3d 428, 441 (5th Cir. 2005)).

       Here, MTC argues that it did not know the officers were working outside of

their scheduled shifts because the officers (1) did not complete time-adjustment

forms to request overtime pay and (2) signed an acknowledgement form included

with each paycheck stating that they submitted such a form for any overtime work

conducted before or after their shift. In other words, MTC maintains that it does not

owe the officers compensation because it did not know they were working before and

after their shift times. But as the officers point out, the facts here do not permit a

logical leap from the absence of time-adjustment forms to MTC’s lack of knowledge.

       Indeed, the cases that MTC cites to support its position—that an employee’s

failure to use an overtime-compensation system always means that the employer does

not know about the work being done—involve an employer’s constructive

knowledge. See White v. Baptist Mem’l Health Care Corp., 699 F.3d 869, 873–77

(6th Cir. 2012) (discussing whether employer should have known employee was

working during lunch break); Hertz v. Woodbury Cty, 566 F.3d 775, 781–82 (8th Cir.

2009) (discussing appropriateness of jury instruction about whether employer should

have known, based on nonpayroll records, that employees were working during

                                            30
commutes and meal breaks); Newton v. City of Henderson, 47 F.3d 746, 748–50 (5th

Cir. 1995) (discussing whether employer should have known employee was working

overtime despite employer’s express denial of overtime authorization and employee’s

failure to report overtime). These cases are not relevant here because, as the officers

point out, this case involves MTC’s actual knowledge that the officers are engaging

in these activities. In particular, MTC requires both the security screening and the

passdown briefing. It cannot simultaneously require an activity and claim to be

unaware that employees are engaging in that activity. Further, it is undisputed that

MTC often has supervisors conduct the preshift briefing; knows the officers check

out keys and equipment because the officers use the inventory-control procedures;

and knows they walk to and from their posts because they show up for work.

      In sum, MTC pays the officers for the eight hours they are at their posts. But it

knows that the officers are working outside those eight hours, on their way to and

from post. And MTC “cannot stand idly by and allow [the officers] to perform

overtime work without proper compensation, even if” the officers did not claim

overtime compensation using the time-adjustment forms or sign acknowledgment

forms. Fairchild, 815 F.3d at 964 (quoting Harvill, 433 F.3d at 441). We therefore

reject MTC’s contention that it did not “suffer or permit” the officers’ work on their

way to and from their posts. § 203(g).

IV.   Rounding

      Finally, we consider the officers’ rounding claim, in which they allege that

MTC’s ten-minute adjustment rule routinely rounds down their work time, resulting

                                           31
in systematic underpayment. Rounding is the practice of “recording the employees’

starting time and stopping time to the nearest [five] minutes, or to the nearest one-

tenth or quarter of an hour,” or to some other consistent time increment. § 785.48(b);

see also McDonald v. Kellogg Co., No. 2011 WL 6180499, at *12–13 (D. Kan. Dec.

13, 2011) (unpublished) (considering rounding claim based on ten-minute adjustment

rule); Russell v. Ill. Bell Tel. Co., 721 F. Supp. 2d 804, 819–20 (N.D. Ill. 2010)

(considering rounding claim based on eight-minute adjustment rule). Federal

regulation permits rounding as long as “it will not result, over a period of time, in

failure to compensate the employees properly for all the time they have actually

worked.” Id.; see also Corbin v. Time Warner Entm’t-Advance/Newhouse P’ship, 821

F.3d 1069, 1075 (9th Cir. 2016) (noting that federal regulation has endorsed use of

rounding for over 50 years). Stated differently, a valid rounding policy must be

“neutral, both facially and as applied.” Corbin, 821 F.3d at 1076 (quoting See’s

Candy Shops, Inc. v. Superior Court, 148 Cal. Rptr. 3d 690, 701 (Cal. Ct. App.

2012)). It must allow for rounding both up and down, so that an employee is

sometimes compensated for time not spent working, and sometimes not compensated

for time spent working. See id. at 1077.

      Recall that under MTC’s ten-minute-adjustment rule, if an officer clocks in or

out more than ten minutes before or after his or her shift time, MTC will pay the

officer based on the time clock rather than on his or her scheduled shift. But if an

officer clocks in or out fewer than ten minutes before or after his or her start time,

MTC will pay the officer based on his or her scheduled eight-hour shift rather than

                                           32
the clock time—in other words, MTC rounds this time off. This rule is facially

neutral because it rounds both up and down. See id. That is, an officer assigned to a 6

a.m. shift who clocks in at 5:51 a.m. and clocks out at 2:09 p.m. will be paid for eight

hours, even though he or she worked at least an 18 additional minutes (nine on either

side). Similarly, an officer who clocks in at 6:09 a.m. and out at 1:51 p.m. will also

be paid for eight hours, even though he or she worked 18 fewer minutes (nine on

either side).

       But the officers presented evidence suggesting that the ten-minute adjustment

rule is not neutrally applied. In particular, they submitted a representative sample

showing that about 94% of the time, the officers were clocked in—and therefore were

performing compensable pre- and postshift activities—for longer than their eight-

hour shift time. And a rounding policy that works in the employer’s favor 94% of the

time is probably not neutrally applied.

       Yet the district court rejected the officers’ rounding claim. The basis for its

decision is not entirely clear, but it concluded that because the officers are paid for

their scheduled shifts under the ten-minute adjustment rule, their “theory of

‘rounding’ . . . violations is incongruous with” their other claims. App. vol. 5, 1155.

In other words, the district court appears to have decided that because this case

involves claims for overtime compensation—that is, for work completed outside of




                                           33
the eight-hour shift—MTC’s ten-minute adjustment rule “does not constitute

‘rounding’ as that concept is used in wage[-]and[-]hour law.”11 Id.

      We disagree that rounding can never be relevant when considering claims for

overtime compensation. The district court cited no authority to support this

proposition, and we have found at least some authority to the contrary. Specifically,

in Russell, the district court denied summary judgment to the employer defendant on

the employees’ rounding claim because if the employer’s “time[-]rounding and

log[-]out policies often caused [employees] to work unpaid overtime in increments of

under eight minutes, then these company-wide practices may have resulted in unpaid

overtime work.” 721 F. Supp. 2d at 820 (emphases added).

      Indeed, the district court’s conclusion that rounding is never relevant to

overtime claims appears to bypass the ultimate issue in this case. We are not

concerned here with whether MTC pays the officers for their full eight-hour shifts;

instead, we are concerned with whether MTC compensates them for work completed

outside of those eight-hour shifts. And if the ten-minute adjustment rule routinely

rounds off that compensable overtime, as the officers’ evidence suggests, then the

officers’ rounding theory remains viable.



      11
         The district court’s ruling may also have turned at least in part on its
conclusion that the officers’ activities after clocking in but before arriving at their
posts were not compensable: the district court noted that “under a true rounding
system, employees are working immediately upon clocking in.” App. vol. 5, 1154.
Yet because we conclude here that these activities are compensable, the district
court’s rounding ruling is flawed to the extent that it turned on its compensability
ruling.
                                            34
      At this stage of the litigation, MTC has not countered the officers’ evidence on

the non-neutrality of its ten-minute adjustment rule. Indeed, MTC’s only argument

against the rounding claim, both below and on appeal, is that the ten-minute

adjustment rule does not amount to rounding because the officers are not doing

compensable work during the time that is rounded off the time clock. We have found

to the contrary. Thus, although “employees who voluntarily come in before their

regular starting time or remain after their closing time[] do not have to be paid for

such periods” as long as “they do not engage in any work,” those are not the facts of

this case. § 785.48(a). And because it appears that the officers have met their initial

burden to show that they are routinely paid only for their shift time even though they

regularly arrive early, leave late, and do work during that time, the district court erred

in granting summary judgment to MTC on the officers’ rounding claim.

                                      Conclusion

      For these detention officers, undergoing the security screening and checking

specialized keys and equipment in and out of a centralized inventory-control system

are integral and indispensable parts of the principal activities that they are employed

to perform: maintaining custody of inmates, searching for contraband, and providing

security. As such, those two activities are compensable under the FLSA, and they

begin and end the officers’ workday. Accordingly, the pre- and postshift activities

that occur in between—the preshift briefing, walking to and from post, and the

passdown briefings—are part of the officers’ continuous workday and are therefore

compensable.

                                           35
       The officers devote at least eight minutes per shift to conducting these pre- and

postshift activities—more than a de minimis amount of time under all the relevant

factors. Further, at least two of these activities, the security screening and the

passdown briefings, are required by MTC policy, so MTC knows that the officers are

engaging in this work. Additionally, because MTC’s compensation system appears to

routinely round down the time that the officers are working, the officers’ rounding

claim survives summary judgment. Accordingly, we reverse the district court’s order

awarding summary judgment to MTC and remand for further proceedings.




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