                     FOR PUBLICATION

    UNITED STATES COURT OF APPEALS
         FOR THE NINTH CIRCUIT


 MICHELLE SALISE FORD,                              No. 18-35794
                Plaintiff-Appellant,
                                                      D.C. No.
                      v.                           2:18-cv-00099-
                                                        BAT
 ANDREW M. SAUL, Commissioner of
 Social Security,
                  Defendant-Appellee.                 OPINION


         Appeal from the United States District Court
           for the Western District of Washington
         Brian Tsuchida, Magistrate Judge, Presiding

                  Submitted October 22, 2019*
                     Seattle, Washington

                     Filed February 20, 2020

  Before: Richard R. Clifton and Sandra S. Ikuta, Circuit
       Judges, and Jed S. Rakoff,** District Judge.

                     Opinion by Judge Ikuta


    *
     The panel unanimously concludes this case is suitable for decision
without oral argument. See Fed. R. App. P. 34(a)(2).
    **
       The Honorable Jed S. Rakoff, United States District Judge for the
Southern District of New York, sitting by designation.
2                            FORD V. SAUL

                            SUMMARY***


                           Social Security

    The panel affirmed the district court’s decision affirming
the Social Security Administration’s denial of a claimant’s
application for disability benefits under Titles II and XVI of
the Social Security Act.

    The panel first considered the claimant’s claim that the
administrative law judge (“ALJ”) erred in rejecting the
opinion of her treating physician, Dr. Medani. The panel
concluded that the ALJ provided specific and legitimate
reasons for rejecting the opinion. First, there was a conflict
between the treating physician’s medical opinion and his own
notes. Second, there was a conflict between the treating
physician’s opinion and the claimant’s activity level. Finally,
Dr. Medani’s opinion lacked explanation.

    The panel rejected claimant’s challenge to the ALJ’s
rejection of the opinion of Dr. Zipperman, an examining
physician. The panel concluded that the ALJ gave specific
and legitimate reasons for rejecting the opinion, and the
reasons were supported by substantial evidence. First, Dr.
Zipperman’s opinion regarding claimant’s functioning was
inconsistent with objective evidence in claimant’s record.
Second, Dr. Zipperman’s opinion was inconsistent with
claimant’s performance at work. Finally, the ALJ reasonably
determined that Dr. Zipperman did not provide useful
statements regarding the degree of claimant’s limitations. The

    ***
        This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                        FORD V. SAUL                           3

panel also held that the ALJ’s duty to develop the record was
not triggered where the ALJ had years of claimant’s health
records and multiple medical opinions to inform the ALJ’s
decision.

    The panel next considered claimant’s argument that the
record supported her claim that she met impairment Listings
1.02 and 1.03, which involve impairments that result in an
inability to ambulate effectively. The panel held that the ALJ
did not err in giving no weight to Dr. Medani’s opinions,
which concluded that claimant’s condition met the criteria of
the listings; and therefore, those opinions did not undercut the
ALJ’s ruling that claimant did not meet Listings 1.02 and
1.03. Second, the panel held that although the ALJ made a
factual error in evaluating claimant’s ability to walk, the error
was harmless because there was ample evidence in the record
supporting the ALJ’s conclusion that claimant did not meet
the Listings. Finally, the ALJ did not err by failing to
consider whether a combination of her impairments medically
equaled the criteria of Listings 1.02 or 1.03.

    Finally, the panel rejected claimant’s argument that the
ALJ erred in failing to order the vocational expert to identify
or provide his source material for his testimony on the
number of jobs that existed in the national economy that
claimant could perform. First, the ALJ’s decision not to issue
a subpoena to the vocational expert to produce the underlying
data did not violate the applicable regulations. Second, the
vocational expert’s failure to produce the data underlying her
testimony did not undermine its reliability. The panel held
that the expert’s testimony cleared the low substantial
evidence bar. Given its inherent reliability, the qualified
vocational expert’s testimony as to the number of jobs
existing in the national economy that a claimant can perform
4                       FORD V. SAUL

was ordinarily sufficient by itself to support the ALJ’s finding
at step five of the sequential evaluation process. The panel
affirmed the ALJ’s conclusion at step five that claimant could
perform a significant number of other jobs in the national
economy, and therefore, she was not disabled.


                         COUNSEL

George Andre Fields, Invictus Legal Services, Sacramento,
California, for Plaintiff-Appellant.

Brian T. Moran, United States Attorney; Kerry Jane Keefe,
Assistant United States Attorney; Mathew W. Pile, Acting
Regional Chief Counsel; Christopher J. Brackett, Special
Assistant United States Attorney; Office of the General
Counsel, Social Security Administration, Region X, Seattle,
Washington; for Defendant-Appellee.


                          OPINION

IKUTA, Circuit Judge:

     In this appeal from a decision of the Social Security
Administration, Michelle Ford claims that the administrative
law judge (ALJ) erred in: (1) failing to give weight to the
opinions of two of her physicians; (2) concluding that her
impairments were not per se disabling under the regulatory
listings; and (3) denying her request to subpoena the data
underlying a vocational expert’s testimony. Because the ALJ
properly provided specific and legitimate reasons for
discounting the opinions of Ford’s physicians, correctly
concluded that Ford’s impairments did not meet a listing, and
                           FORD V. SAUL                                5

was entitled to rely on the vocational expert’s testimony
despite the expert’s failure to provide information about the
sources underlying the testimony, we affirm.

                                    I

    To determine whether an individual is disabled within the
meaning of the Social Security Act, and therefore eligible for
benefits, an ALJ follows a five-step sequential evaluation.
See 20 C.F.R. § 404.1520.1 The burden of proof is on the
claimant at steps one through four. See Valentine v. Comm’r
of Soc. Sec. Admin., 574 F.3d 685, 689 (9th Cir. 2009). At
step one, the ALJ must determine if the claimant is presently
engaged in a “substantial gainful activity,”
§ 404.1520(a)(4)(i), defined as “work done for pay or profit
that involves significant mental or physical activities,” Lewis
v. Apfel, 236 F.3d 503, 515 (9th Cir. 2001) (citing
§§ 404.1571–404.1572, 416.971–416.975). At step two, the
ALJ decides whether the claimant’s impairment or
combination of impairments is “severe,” § 404.1520(a)(4)(ii),
meaning that it significantly limits the claimant’s “physical



    1
       Title II of the Social Security Act provides benefits to disabled
individuals who are insured by virtue of working and paying Federal
Insurance Contributions Act (FICA) taxes for a certain amount of time.
Title XVI of the Social Security Act is a needs-based program funded by
general tax revenues designed to help disabled individuals who have low
or no income. Ford brought claims under both programs. Although each
program is governed by a separate set of regulations, the regulations
governing disability determinations are substantially the same for both
programs. Compare 20 C.F.R. §§ 404.1501–1599 (governing disability
determinations under Title II) with 20 C.F.R. §§ 416.901–999d (governing
disability determinations under Title XVI). For convenience, we cite only
the regulations governing disability determinations under Title II.
6                         FORD V. SAUL

or mental ability to do basic work activities,” § 404.1522(a);
see Webb v. Barnhart, 433 F.3d 683, 686 (9th Cir. 2005).

     At step three, the ALJ evaluates whether the claimant has
an impairment, or combination of impairments, that meets or
equals the criteria of any of the impairments listed in the
“Listing of Impairments” (referred to as the “listings”). See
§ 404.1520(a)(4)(iii); 20 C.F.R. Pt. 404 Subpt. P, App. 1
(pt. A). The listings describe impairments that are considered
“to be severe enough to prevent an individual from doing any
gainful activity.” § 404.1525(a). Each impairment is
described in terms of “the objective medical and other
findings needed to satisfy the criteria of that listing.”
§ 404.1525(c)(3). “For a claimant to show that his
impairment matches a listing, it must meet all of the specified
medical criteria. An impairment that manifests only some of
those criteria, no matter how severely, does not qualify.”
Sullivan v. Zebley, 493 U.S. 521, 530 (1990) (footnote
omitted). If an impairment does not meet a listing, it may
nevertheless be “medically equivalent to a listed impairment”
if the claimant’s “symptoms, signs, and laboratory findings
are at least equal in severity to” those of a listed impairment.
§ 404.1529(d)(3).2 But a claimant cannot base a claim of




    2
      “Symptoms means your own description of your physical or mental
impairment.” § 404.1502(i).

     “Signs means one or more anatomical, physiological, or
psychological abnormalities that can be observed, apart from your
statements (symptoms). Signs must be shown by medically acceptable
clinical diagnostic techniques.       Psychiatric signs are medically
demonstrable phenomena that indicate specific psychological
abnormalities, e.g., abnormalities of behavior, mood, thought, memory,
                            FORD V. SAUL                                7

equivalence on symptoms alone. Even if the claimant alleges
pain or other symptoms that makes the impairment more
severe, the clamant’s impairment does not medically equal a
listed impairment unless the claimant has signs and
laboratory findings that are equal in severity to those set forth
in a listing. § 404.1529(d)(3). If a claimant’s impairments
meet or equal the criteria of a listing, the claimant is
considered disabled. § 404.1520(d).

    If the claimant does not meet or equal a listing, the ALJ
proceeds to step four, where the ALJ assesses the claimant’s
residual functional capacity (RFC)3 to determine whether the
claimant can perform past relevant work, § 404.1520(e),
which is defined as “work that [the claimant has] done within
the past 15 years, that was substantial gainful activity, and
that lasted long enough for [the claimant] to learn to do it,”
§ 404.1560(b)(1). If the ALJ determines, based on the RFC,
that the claimant can perform past relevant work, the claimant
is not disabled. § 404.1520(f).

    At step five, the burden shifts to the agency to prove that
“the claimant can perform a significant number of other jobs


orientation, development, or perception, and must also be shown by
observable facts that can be medically described and evaluated.”
§ 404.1502(g).

     “Laboratory findings means one or more anatomical, physiological,
or psychological phenomena that can be shown by the use of medically
acceptable laboratory diagnostic techniques. Diagnostic techniques
include chemical tests (such as blood tests), electrophysiological studies
(such as electrocardiograms and electroencephalograms), medical imaging
(such as X-rays), and psychological tests.” § 404.1502(c).
    3
      A claimant’s RFC is defined as “the most [the claimant] can still do
despite [the claimant’s] limitations.” § 404.1545(a)(1).
8                           FORD V. SAUL

in the national economy.” Thomas v. Barnhart, 278 F.3d 947,
955 (9th Cir. 2002). To meet this burden, the ALJ may rely
on the Medical-Vocational Guidelines found at 20 C.F.R.
Pt. 404 Subpt. P, App. 2,4 or on the testimony of a vocational
expert. Tackett v. Apfel, 180 F.3d 1094, 1101 (9th Cir. 1999).
“[A] vocational expert or specialist may offer expert opinion
testimony in response to a hypothetical question about
whether a person with the physical and mental limitations
imposed by the claimant’s medical impairment(s) can meet
the demands of the claimant’s previous work, either as the
claimant actually performed it or as generally performed in
the national economy.” § 404.1560(b)(2). An ALJ may also
use “other resources, such as the ‘Dictionary of Occupational
Titles’ and its companion volumes and supplements,
published by the Department of Labor.” Id.

    Throughout the five-step evaluation, the ALJ “is
responsible for determining credibility, resolving conflicts in
medical testimony, and for resolving ambiguities.” Andrews
v. Shalala, 53 F.3d 1035, 1039 (9th Cir. 1995).

                                    II

    We now turn to the facts of this case. On October 24,
2008, Michelle Ford applied for disability benefits under Title
II and XVI. Her first disability application was denied in

    4
      The Medical-Vocational Guidelines “relieve the Secretary of the
need to rely on vocational experts by establishing through rulemaking the
types and numbers of jobs that exist in the national economy.” Heckler
v. Campbell, 461 U.S. 458, 461 (1983). The Guidelines “consist of a
matrix of the four factors identified by Congress—physical ability, age,
education, and work experience—and set forth rules that identify whether
jobs requiring specific combinations of these factors exist in significant
numbers in the national economy.” Id. at 461–62 (footnotes omitted).
                        FORD V. SAUL                         9

2011; the ALJ found that Ford was not disabled for the period
between August 2007 and March 2011, and that decision
became final when Ford declined to appeal it further. Ford
then filed a second application for benefits, claiming that she
became disabled on March 26, 2011, due to a variety of
physical and mental impairments. In January 2015, an ALJ
held that Ford was disabled as of November 1, 2012, but not
before that date. The Appeals Council vacated the decision
and remanded for a new hearing, which the ALJ conducted in
November 2016. At the hearing, Ford introduced evidence
regarding both her physical and mental impairments. In
March 2017, the ALJ ruled that Ford was not disabled for the
period from March 26, 2011 to January 2, 2016. The Appeals
Council denied Ford’s request for review, and the district
court affirmed. This appeal followed.

                              A

    The following evidence regarding Ford’s alleged physical
impairments, adduced at the November 2016 hearing, is
relevant to this appeal. Over the course of 2011, Ford
routinely visited Dr. Ignatius Medani, her primary care
physician. She typically reported back pain, shoulder pain,
nausea, and anxiety. Dr. Medani’s notes, however, showed
few objective findings related to her pain and no consistent
abnormalities, outside of a diagnosis of “very mild” carpal
tunnel syndrome. He frequently prescribed pain medications
at Ford’s request. In October 2011, a non-examining
physician examined Ford’s medical record as part of her
application for benefits. His report concluded that Ford was
not disabled because her RFC allowed her to perform
sedentary work.
10                             FORD V. SAUL

    In April 2012, Ford had surgery on her right foot for heel
spurs and Achilles tendinitis. In December 2012, another
non-examining physician reviewed Ford’s medical record and
concluded that Ford was not disabled. Ford’s condition
continued to improve over the course of 2013 and 2014. In
September 2014, Ford had surgery to remove a bunion and a
soft tissue mass on her right toe. During recovery, she used
a scooter to avoid putting weight on the affected foot. In
August and September 2014, Ford saw Dr. Medani several
times for medication refills. The examinations at these visits
were unremarkable, and Dr. Medani made few notes. Other
than a finding of reduced lumbar range of motion, Dr. Medani
noted no abnormalities.

   In late September 2014, Dr. Medani filled out an
“Arthritis Residual Functional Capacity Questionnaire.” The
questionnaire set out the disability criteria of Listings 1.02
and 1.03 from the “Listings of Impairments.”

    Listing 1.02 is entitled “Major dysfunction of a joint(s)
(due to any cause),” and describes that impairment as
“[c]haracterized by gross anatomical deformity” and
involving a “major peripheral weight bearing joint (i.e., hip,
knee or ankle), resulting in inability to ambulate effectively,
as defined in 1.00B2b.” 20 C.F.R. Pt. 404, Subpt. P, App. 1
§ 1.02.5

     5
         Listing 1.02 provides, in full:

           Major dysfunction of a joint(s) (due to any cause):
           Characterized by gross anatomical deformity (e.g.,
           subluxation, contracture, bony or fibrous ankylosis,
           instability) and chronic joint pain and stiffness with
           signs of limitation of motion or other abnormal motion
           of the affected joint(s), and findings on appropriate
                              FORD V. SAUL                               11

    Listing 1.03 is entitled “Reconstructive surgery or
surgical arthrodesis of a major weight-bearing joint,” and the
impairment is characterized by “inability to ambulate
effectively, as defined in 1.00B2b.” 20 C.F.R. Pt. 404, Subpt.
P, App. 1 § 1.03.6

    Section 1.00(B)(2)(b) provides a detailed definition of the
term “inability to ambulate effectively.” See 20 C.F.R. Pt.
404, Subpt. P, App. 1 § 1.00(B)(2)(b)(1). According to the
definition section, “[i]nability to ambulate effectively means
an extreme limitation of the ability to walk; i.e., an
impairment(s) that interferes very seriously with the
individual’s ability to independently initiate, sustain, or
complete activities.” Id. Further, “[i]neffective ambulation


          medically acceptable imaging of joint space narrowing,
          bony destruction, or ankylosis of the affected joint(s).
          With:

          A. Involvement of one major peripheral weight-bearing
          joint (i.e., hip, knee, or ankle), resulting in inability to
          ambulate effectively, as defined in 1.00B2b;

          or

          B. Involvement of one major peripheral joint in each
          upper extremity (i.e., shoulder, elbow, or wrist-hand),
          resulting in inability to perform fine and gross
          movements effectively, as defined in 1.00B2c.
   6
       Listing 1.03 provides, in full:

          Reconstructive surgery or surgical arthrodesis of a
          major weight-bearing joint, with inability to ambulate
          effectively, as defined in 1.00B2b , and return to
          effective ambulation did not occur, or is not expected to
          occur, within 12 months of onset.
12                      FORD V. SAUL

is defined generally as having insufficient lower extremity
functioning . . . to permit independent ambulation without the
use of a hand-held assistive device(s) that limits the
functioning of both upper extremities.” Id. The definition
also states that “examples of ineffective ambulation include,
but are not limited to, the inability to walk without the use of
a walker, two crutches or two canes . . . .” 20 C.F.R. Pt. 404,
Subpt. P, App. 1 § 1.00(B)(2)(b)(2).

    After quoting the criteria for these listings, the
questionnaire asked, “In your opinion to a degree of medical
certainty, does Ms. Ford’s condition meet or equal the above
criteria?” Dr. Medani answered “Yes.” In response to the
next question, “Please explain,” he wrote only, “Condition is
permanent.”

    The questionnaire also provided a series of check boxes
allowing the doctor to indicate the severity of Ford’s
conditions. Dr. Medani checked boxes expressing the
following opinions: (1) Ford could not sit or stand for more
than five minutes at a time or more than two hours in a
workday; (2) Ford needed to shift positions at will and take
unscheduled breaks every five minutes; (3) Ford needed to
elevate her legs for 80% of the day; (4) Ford could rarely lift
less than ten pounds and never lift more than ten pounds or
engage in actions such as climbing stairs, crouching, or
stooping; (5) Ford could perform manipulative actions for no
more than 5% of a workday; (6) Ford would miss more than
four days of work a month; and (7) Ford was incapable of
even low-stress jobs.

    From 2015 to 2016, Ford’s physical examinations were
routinely normal, and she saw Dr. Medani only to have pain
medications refilled.
                       FORD V. SAUL                        13

                              B

    In addition to this evidence regarding her physical
condition, Ford also provided the following evidence
regarding her mental condition. In August 2011, she received
counseling at Valley Cities Counseling & Consultation
(“Valley Cities”). She reported feeling depressed and
anxious, and admitted to taking more medication than
prescribed to cope with these feelings. Ford canceled or
failed to show up for at least five appointments at Valley
Cities over the next four months. In October 2011, a non-
examining psychiatrist concluded that Ford could perform
simple tasks and familiar complex tasks, attend work within
customary tolerances, and complete a normal workday. In
June and September 2012, Ford returned to Valley Cities to
have her medication refilled. At each visit, she reported
increased depression, stress, and anxiety. In September, the
counselor diagnosed her with a depressive disorder with
psychotic features, but flagged the possibility of substance-
induced mood disorder. The counselor also reported her
objective observations that Ford was well groomed, alert and
oriented as to person, place, time, and situation, her speech
was regular in rate and rhythm, and there was no evidence of
psychosis.

    In November 2012, Ford saw examining psychiatrist
Michelle Zipperman for a consultation. In her report, Dr.
Zipperman diagnosed Ford with post-traumatic stress
disorder, psychosis, depression with psychotic features, and
panic disorder. She also indicated that Ford’s ability to
function in the workplace was “limited.” Although Dr.
Zipperman noted that “the claimant’s ability to accept
instructions from supervisors is fair” and “[t]he claimant’s
ability to interact with coworkers in the public is fair,” she
14                     FORD V. SAUL

concluded that “claimant’s ability to maintain attention and
concentration is limited,” her “ability to maintain regular
attendance in the workplace is limited,” and “her ability to
deal with the usual stress encountered in the workplace is
poor to limited.”

    Later in November 2012, Ford returned to Valley Cities,
and reported a depressed mood, panic attacks, and
hallucinations. Again, the counselor found Ford had regular
speech, thought, and orientation. Ford missed or cancelled
three of her next four appointments. In December 2012, a
non-examining psychiatrist again concluded that Ford
remained capable of attending work within customary
tolerances, working within a routine, and completing simple
tasks and familiar complex tasks.

    Ford’s mental health treatments in 2013 were sporadic.
In February 2013, she reported panic attacks, but her
counselor noted that her attention and concentration were
“fair” and that she “[did] not appear psychotic.” Evaluations
from her April 2013 visit also showed no evidence of
psychosis and normal concentration. In May 2013, Ford’s
counselor noted Ford was “alert and oriented in all spheres.”
Ford made occasional mental health visits to Valley Cities
over the course of 2013 through 2015. She frequently
canceled appointments or failed to show up for them. When
she did appear at the scheduled appointments, she showed
normal memory, attention, and concentration. She reported
no paranoia or delusions at her appointment in November
2014.
                        FORD V. SAUL                        15

                              C

    The record also contained information about Ford’s work
history. Ford was able to work in temporary jobs over the
course of 2015, and began working part-time at FedEx in
May 2016. Ford worked approximately 12 to 13 hours a
week at FedEx on tasks that included scanning, labeling and
sorting packages. On some days, her shifts lasted for six to
eight hours. Ford worked by herself and with coworkers. By
July 2017, she had quit her job at FedEx.

                              D

    At the November 2016 hearing, the ALJ called a
vocational expert to testify whether a significant number of
jobs existed in the national economy that a claimant with
Ford’s RFC could perform. The vocational expert testified
that 130,000 addresser and 9,800 ink-printing jobs existed
nationwide and that Ford’s RFC allowed her to perform these
jobs. In response to cross-examination about how he had
derived those estimates, the vocational expert stated “[m]y
numbers come from a variety of sources which include the
Department of Labor and the U.S. Chamber of Commerce
and actually Social Security, itself, the Census Bureau,
through the [International Trade Administration], supply
really good numbers and, believe it or not, the state of Alaska
has good national numbers.” Probing the expert’s conclusion
regarding the number of addresser jobs, Ford’s counsel asked
“[w]hich publication indicated that there were that number of
jobs?” The expert responded, “I don’t have that information
in my notes. I typically average all my sources.” The
counsel then asked, “What were the numbers that you
averaged together to get 130,000?” Again, the expert
responded, “I don’t have that information in my notes,
16                      FORD V. SAUL

either.” The expert explained that he averages the numbers
from his various sources once a year, and then puts those
numbers in his notes. Ford’s counsel then stated he had no
further questions.

    A week after the hearing, Ford’s attorney asked the ALJ
to subpoena the vocational expert’s documentation regarding
the number of jobs available nationwide. The ALJ did not
respond to the subpoena request before rendering a final
decision.

                              E

    In her opinion, the ALJ determined that Ford was not
engaged in substantial gainful activity. At step two, the ALJ
determined that Ford had a number of severe impairments.

    Moving to step three, the ALJ rejected Ford’s argument
that she met or equaled the criteria of any listing. Among
other things, the ALJ concluded that Ford did not have a
severe ambulation problem, and had used a walker and
scooter only during a period of recovery for foot surgery.
Therefore, she did not have an ineffective ability to ambulate,
and her impairments did not “meet or equal” Listings 1.02 or
1.03.

    The ALJ then concluded that Ford had the RFC to
perform sedentary work, as defined, with certain limitations.
In reaching this conclusion, the ALJ declined to give weight
to Dr. Medani’s opinion regarding Ford’s functional
limitations, because it was inconsistent with the objective
evidence and poorly explained. The ALJ also declined to
give weight to Dr. Zipperman’s report, because it included
conflicting statements, was inconsistent with other evidence
                        FORD V. SAUL                         17

in the record, and did not provide useful statements about
Ford’s functional limitations (instead using terms like “fair”
and “limited”). The ALJ also gave no weight to Ford’s own
testimony, finding it to be inconsistent internally and
inconsistent with objective medical evidence in the record.
Among other things, the ALJ noted that Ford’s self-reports
were undermined by her propensity to exaggerate her
symptoms, her improving physical state, and her poor follow-
through with mental health treatment.

    Turning to step five, the ALJ concluded that a significant
number of jobs existed in the national economy that Ford
could perform based on the vocational expert’s testimony.
Accordingly, the ALJ concluded that Ford was not disabled
prior to January 2, 2016. Beginning on that date, however,
Ford’s age category changed from “younger person” to
“person closely approaching advanced age,” § 404.1563
(c)–(d), and based on the same RFC, the regulations directed
a finding that she was disabled as of that date.

                              III

     On appeal, Ford argues that the ALJ erred in: (1) giving
little or no weight to the opinions of two of her physicians,
Dr. Medani and Dr. Zipperman; (2) concluding that Ford did
not have an impairment that meets or medically equals the
severity of the impairments in Listings § 1.02 and 1.03; and
(3) failing to grant Ford’s request to subpoena the data
underlying the vocational expert’s testimony. We address
each of these alleged errors in turn.

    We have jurisdiction under 28 U.S.C. § 1291. “We
review the district court’s order affirming the ALJ’s denial of
social security benefits de novo, and will disturb the denial of
18                      FORD V. SAUL

benefits only if the decision ‘contains legal error or is not
supported by substantial evidence.’” Tommasetti v. Astrue,
533 F.3d 1035, 1038 (9th Cir. 2008) (citation omitted)
(quoting Orn v. Astrue, 495 F.3d 625, 630 (9th Cir. 2007)).
“Substantial evidence . . . is ‘more than a mere scintilla,’” and
means only “such relevant evidence as a reasonable mind
might accept as adequate to support a conclusion.” Biestek v.
Berryhill, 139 S. Ct. 1148, 1154 (2019) (quoting Consol.
Edison Co. v. NLRB, 305 U.S. 197, 229 (1938)). If the
evidence “is susceptible to more than one rational
interpretation, it is the ALJ’s conclusion that must be
upheld.” Burch v. Barnhart, 400 F.3d 676, 679 (9th Cir.
2005). We may affirm the ALJ’s decision even if the ALJ
made an error, so long as the error was harmless, meaning it
was “inconsequential to the ultimate nondisability
determination.” Tommasetti, 533 F.3d at 1038 (quoting
Robbins v. Soc. Sec. Admin., 466 F.3d 880, 885 (9th Cir.
2006)). An ALJ’s denial of a subpoena is reviewed for abuse
of discretion. See Solis v. Schweiker, 719 F.2d 301, 302 (9th
Cir. 1983).

                               A

    We first consider Ford’s claim that the ALJ erred in
rejecting the opinion of her treating physician, Dr. Medani.

    As a general rule, a treating physician’s opinion is entitled
to “substantial weight.” Embrey v. Bowen, 849 F.2d 418, 422
(9th Cir. 1988). Nevertheless, the ALJ need not accept the
opinion of a treating physician. If a treating physician’s
opinion is not contradicted by other evidence in the record,
the ALJ may reject it only for “clear and convincing” reasons
supported by substantial evidence in the record. See Ryan v.
Comm’r of Soc. Sec. Admin., 528 F.3d 1194, 1198 (9th Cir.
                        FORD V. SAUL                        19

2008). But “if the treating doctor’s opinion is contradicted by
another doctor,” the ALJ may discount the treating
physician’s opinion by giving “specific and legitimate
reasons” that are supported by substantial evidence in the
record. Lester v. Chater, 81 F.3d 821, 830 (9th Cir. 1995).
“The ALJ need not accept the opinion of any physician,
including a treating physician, if that opinion is brief,
conclusory, and inadequately supported by clinical findings.”
Thomas, 278 F.3d at 957.

    Because Dr. Medani’s opinions regarding Ford’s
functional capacity were contradicted by the reports of two
non-examining physicians, the ALJ could reject the opinions
by giving “specific and legitimate reasons” for doing so. See
Bayliss v. Barnhart, 427 F.3d 1211, 1216 (9th Cir. 2005).
According to Ford, the ALJ erred because Dr. Medani’s
opinions were supported by the record, and the ALJ failed to
give adequate reasons for discounting them. We disagree.
Among other reasons, the ALJ stated that Dr. Medani’s
opinion regarding Ford’s functional capacity was inconsistent
with medical evidence, including previous medical opinions
contained in his own notes. This conclusion was supported
by substantial evidence in the record. For example,
Dr. Medani’s opinion indicates that Ford could perform
manipulative movements with her hands for only five percent
of the day, but his treatment notes state that Ford had “very
mild” carpal tunnel syndrome. A conflict between a treating
physician’s medical opinion and his own notes is a “clear and
convincing reason for not relying on the doctor’s opinion,”
and therefore is also a specific and legitimate reason for
rejecting it. Id.

    The ALJ also stated that Dr. Medani’s opinion was
inconsistent with Ford’s activity level. This reason was
20                      FORD V. SAUL

likewise supported by substantial evidence. Dr. Medani
checked a box stating that Ford could not sit or stand for more
than five minutes at a time or two hours in a workday, yet
Ford worked six to eight hour shifts at FedEx in 2016 where
she was required to sit and stand for long periods of time. A
conflict between a treating physician’s opinion and a
claimant’s activity level is a specific and legitimate reason for
rejecting the opinion. See Rollins v. Massanari, 261 F.3d
853, 856 (9th Cir 2001).

    Finally, the ALJ noted that Dr. Medani’s opinion lacked
explanation. An ALJ is not required to take medical opinions
at face value, but may take into account the quality of the
explanation when determining how much weight to give a
medical opinion. See Orn, 495 F.3d at 631; 20 C.F.R.
§ 404.1527(c)(3). While an opinion cannot be rejected merely
for being expressed as answers to a check-the-box
questionnaire, Popa v. Berryhill, 872 F.3d 901, 907 (9th Cir.
2017), “the ALJ may permissibly reject check-off reports that
do not contain any explanation of the bases of their
conclusions,” Molina v. Astrue, 674 F.3d 1104, 1111 (9th Cir.
2012) (cleaned up) (quoting Crane v. Shalala, 76 F.3d 251,
253 (9th Cir.1996)). When Dr. Medani was asked in the
questionnaire to explain why Ford met the criteria of Listings
1.02 and 1.03, which require specific medical diagnoses, he
wrote only, “Condition is permanent,” which does not explain
the basis for Dr. Medani’s conclusion.             Moreover,
Dr. Medani’s conclusion that Ford met these listings is
contradicted by the medical record, which does not contain
any reference to a “gross anatomical deformity” (as required
by Listing 1.02) or “[r]econstructive surgery or surgical
                           FORD V. SAUL                              21

arthrodesis of a major weight-bearing joint” (as required by
Listing 1.03).7

                                   B

    Ford also challenges the ALJ’s rejection of the opinion of
Dr. Zipperman, an examining physician. “The opinion of an
examining physician is . . . entitled to greater weight than the
opinion of a nonexamining physician.” Lester v. Chater,
81 F.3d 821, 830 (9th Cir. 1995). If the opinion of an
examining doctor is contradicted by another doctor, it “can
only be rejected for specific and legitimate reasons that are
supported by substantial evidence in the record.” Id. at
830–31. An ALJ needs less substantial evidence to reject an
examining physician’s opinion than to reject an treating
physician’s opinion. Id. at 831 n.8.

    7
       Ford also challenges the ALJ’s rejection of Dr Medani’s diagnoses
of chronic pain syndrome and fibromyalgia. The ALJ based her
conclusion on the ground that Dr Medani failed to document the bases for
such diagnoses (such as identifying the requisite tender points or ruling
out other causes). Under the social security rules, a physician may
diagnose fibromyalgia if the patient meets the 1990 or 2010 criteria
established by the American College of Rheumatology (ACR). See SSR
12-2P, 2012 WL 3104869 (July 25, 2012). According to Ford, the ALJ
erred because the ALJ rejected Dr. Medani’s diagnosis of fibromyalgia
solely on the ground that Dr. Medani did not explain how Ford’s condition
satisfied the 1990 criteria, and failed to recognize that the medical
documentation and opinions from Dr. Medani demonstrate that Ford’s
condition met the 2010 criteria. This argument fails. Dr. Medani’s
diagnosis consisted only of the single word “fibromyalgia,” and did not
explain how Ford met either the 1990 or the 2010 criteria. Nor does Ford
point to evidence in the record satisfying the 2010 criteria. Moreover,
because both the 1990 and 2010 criteria require a physician to rule out
other possible causes of a claimant’s pain, SSR 12-2P(II)(A)(3), (B)(3),
the ALJ’s determination that Dr. Medani failed to do so establishes that
Dr. Medani’s fibromyalgia diagnosis does not meet either criterion.
22                      FORD V. SAUL

    Ford claims that the ALJ erred in rejecting
Dr. Zipperman’s opinion because the ALJ’s reasons for doing
so were not supported by the record. Again, we disagree.
Here, Dr. Zipperman’s opinion was contradicted by the
opinions of other physicians, and so the ALJ was required to
give only “specific and legitimate” reasons for rejecting the
opinion. The ALJ did so, and her reasons were supported by
substantial evidence.

    First, the ALJ concluded that Dr. Zipperman’s opinion
regarding Ford’s functioning was inconsistent with objective
evidence in Ford’s record. Substantial evidence supports this
conclusion. For instance, Dr. Zipperman concluded that Ford
was highly distractible and her ability to concentrate was
limited, but other mental health professionals found that Ford
had normal concentration and thought processes. Although
Ford argues that the ALJ failed to recognize the inherently
variable nature of mental illness, “[t]he court will uphold the
ALJ’s conclusion when the evidence is susceptible to more
than one rational interpretation.” Tommasetti, 533 F.3d
at 1038.

    The ALJ also found that Dr. Zipperman’s opinion was
inconsistent with Ford’s performance at work. This finding
is also supported by substantial evidence. Dr. Zipperman
concluded that Ford’s ability to maintain regular work
attendance was limited, her ability to deal with usual
workplace stress was poor to limited, and her ability to
perform work duties at a sufficient pace was poor. This
conclusion was inconsistent with Ford’s work for FedEx,
which demonstrated an ability to sustain a work schedule,
tolerate work-related stress, and perform simple tasks. An
ALJ may consider any work activity, including part-time
work, in determining whether a claimant is disabled, see
                             FORD V. SAUL                               23

Drouin v. Sullivan, 966 F.2d 1255, 1258 (9th Cir. 1992), and
here Ford’s own testimony established that she was able to
work occasional eight-hour shifts.

    Finally, the ALJ determined that Dr. Zipperman did not
provide useful statements regarding the degree of Ford’s
limitations. Here, the ALJ found that Dr. Zipperman’s
descriptions of Ford’s ability to perform in the workplace as
“limited” or “fair” were not useful because they failed to
specify Ford’s functional limits. Therefore, the ALJ could
reasonably conclude these characterizations were inadequate
for determining RFC. Ford contends that the ALJ should
have recontacted Dr. Zipperman to further develop the record
regarding the meaning of “fair” and “limited” in Zipperman’s
opinions. See 20 C.F.R. § 404.1520b(b)(2)(i). But “[a]n
ALJ’s duty to develop the record further is triggered only
when there is ambiguous evidence or when the record is
inadequate to allow for proper evaluation of the evidence.”
Mayes v. Massanari, 276 F.3d 453, 459–60 (9th Cir. 2001).
Given that the ALJ had years of Ford’s mental health records
and multiple opinions from non-examining psychiatrists to
inform her decision, this duty was not triggered.8

                                    C

    We next turn to Ford’s argument that the record supports
her claim that she meets Listings 1.02 and 1.03, and the



    8
      Because the ALJ provided specific and legitimate reasons supported
by substantial evidence to justify her rejection of Dr. Zipperman’s opinion,
we do not address Ford’s argument that other reasons provided by the ALJ
were not supported by the record. See Carmickle v. Comm’r, Soc. Sec.
Admin., 533 F.3d 1155, 1162 (9th Cir. 2008).
24                          FORD V. SAUL

ALJ’s conclusion to the contrary was not supported by
substantial evidence.

    In making this argument, Ford relies primarily on
Dr. Medani’s conclusion that her condition meets the criteria
of these two listings. For the reasons explained above,
however, the ALJ did not err in giving Dr. Medani’s opinions
no weight, and therefore, these opinions do not undercut the
ALJ’s ruling.9

    Ford also argues that the ALJ made both a legal and
factual error that undermine the conclusion that her condition
does not meet the listings. First, she claims that the ALJ
made a legal error in mistakenly concluding that a claimant
cannot meet either listing unless the claimant uses an assistive
device. This argument mischaracterizes the ALJ’s opinion.
The ALJ did not state or suggest that use of an assistive
device was necessary to prove ineffective ability to ambulate.
Rather, the ALJ stated that Ford did not use “any assistive
device for long-term” in connection with her observation that
Ford had used a walker and scooter on a temporary basis
during recovery from foot surgery, but otherwise did not
require such devices. Moreover, the ALJ’s determination that
the record was devoid of evidence that Ford lacked the ability
to ambulate or had any severe ambulation problem was based
on other evidence in the record, such as Ford’s “self-reports
or remarks by providers.”



     9
        Even if the ALJ had decided to credit Dr. Medani’s opinion, the
applicable regulations instruct that such a “[s]tatement[] about whether or
not [the claimant’s] impairment(s) meets or medically equals any listing
in the Listing of Impairments” would be “neither valuable nor persuasive.”
20 C.F.R. § 404.1520b(c)(3)(iv).
                          FORD V. SAUL                             25

    Second, Ford argues that the ALJ erred in evaluating
Ford’s ability to walk. Ford points to the “Function Report -
Adult” that she filled out in August 2011 as part of her claims
process. In response to the question, “How far can you walk
before needing to stop and rest?” Ford responded “maybe 1/4
of a block.”10 The ALJ, however, mistakenly characterized
these reports as stating that Ford “could walk maybe 1/4
mile.” Although the ALJ made a factual error on this point,
the misstatement is harmless because there is ample evidence
in the record supporting the ALJ’s conclusion that Ford did
not meet Listing 1.02 or 1.03. Among other things, there is
no evidence in the record that Ford suffered a gross
anatomical deformity, one of the required criteria to meet
Listing 1.02, nor any evidence that she had reconstructive
surgery of a major weight-bearing joint, one of the required
criteria to meet Listing 1.03. Because a claimant’s
impairment does not match a listing unless it meets “all of the
specified medical criteria,” Sullivan, 493 U.S. at 530, the
ALJ’s error in considering how far Ford could walk is
“inconsequential to the ultimate nondisability determination,”
Tommasetti, 533 F.3d at 1038 (citation omitted).

    Finally, Ford argues that the ALJ erred by failing to
consider whether a combination of her impairments medically
equalled the criteria of Listings 1.02 or 1.03. This argument
also fails, because “[a]n ALJ is not required to discuss the
combined effects of a claimant’s impairments or compare
them to any listing in an equivalency determination, unless
the claimant presents evidence in an effort to establish
equivalence.” Burch, 400 F.3d at 683; see also Lewis,
236 F.3d at 514. While Ford’s attorney made passing

     10
        A non-examining physician repeated Ford’s claim that her “walk
tolerance is 1/4 block.”
26                      FORD V. SAUL

reference to a “combination of impairments” at the
administrative hearing before the ALJ, he did not argue or
explain how such a combination was medically equal to a
gross anatomical deformity under Listing 1.02 or a
reconstructive surgery of a major weight-bearing joint under
Listing 1.03. Because the ALJ did not have an obligation to
discuss medical equivalency sua sponte, the ALJ did not err
in failing to do so. See Burch, 400 F.3d at 683.

                              D

    Finally, Ford argues that the ALJ erred in failing to order
the vocational expert to identify or provide his source
material for his testimony on the number of jobs that exist in
the national economy that Ford could perform. Ford first
claims that she needed the underlying data to make a
meaningful challenge to the vocational expert’s testimony.
According to Ford, the ALJ’s failure to issue a subpoena
requiring the vocational expert to produce the underlying data
violated the applicable regulations and procedural rules, and
violated her due process rights. Second, Ford argues that the
vocational expert’s failure to produce the data underlying his
testimony undermined its reliability, and therefore the
testimony did not constitute substantial evidence supporting
the ALJ’s determination at step five.

     We disagree on both points. First, the ALJ’s decision not
to issue a subpoena to the vocational expert did not violate
the applicable regulations. Under the regulations, “[w]hen it
is reasonably necessary for the full presentation of a case” a
party may request that the ALJ issue subpoenas “for the
production of books, records, correspondence, papers, or
other documents that are material to an issue at the hearing.”
20 C.F.R § 404.950(d)(1). To obtain such a subpoena, a party
                          FORD V. SAUL                             27

“must file a written request for the issuance of a subpoena
with the administrative law judge . . . at least 5 business days
before the hearing date” unless the party shows that it has an
“unusual, unexpected, or unavoidable circumstance” beyond
the party’s control, as listed in § 404.935(b), which prevented
the party from doing so. 20 C.F.R. § 404.950(d)(2) (2013).11
Here, Ford made her request for a subpoena a week after the
hearing. Therefore, she did not meet the regulatory
requirement that such requests be made “at least 5 days
before the hearing date.” Ford does not point to any authority
entitling a claimant to make a post-hearing request or
requiring an ALJ to consider issuing a post-hearing subpoena.
Nor does she argue that an “unusual, unexpected, or
unavoidable circumstance” prevented her from making her
request at least 5 days before the hearing date. Accordingly,
the ALJ did not violate the applicable regulations.

    Nor is there any “free-standing procedural rule under
which a vocational expert would always have to produce [her
underlying data] upon request.” Biestek, 139 S. Ct. at 1154.
In federal court, “an expert witness must produce all data she
has considered in reaching her conclusions,” but “no similar
requirement applies in SSA hearings.” Id. (citing Fed. R.
Civ. P. 26(a)(2)(B)). We have likewise held that “[t]he
requirements for the admissibility of expert testimony under
Federal Rule of Evidence 702 . . . do not apply to the
admission of evidence in Social Security administrative
proceedings.” Bayliss, 427 F.3d at 1218 n.4. Rather, “[a
vocational expert]’s recognized expertise provides the



    11
       This regulation was subsequently amended to require the request
for a subpoena to be made 10 days prior to the hearing. 20 C.F.R.
§§ 404.950(d)(2), 416.1450(d)(1).
28                          FORD V. SAUL

necessary foundation for his or her testimony” and “no
additional foundation is required.” Id. at 1281.12

    Second, Ford argues that the vocational expert’s failure to
produce the data underlying her testimony undermined its
reliability. Therefore, Ford contends, the expert’s testimony
did not constitute substantial evidence of the number of jobs
that exist in the national economy. This argument also fails.
Our review of an ALJ’s fact-finding for substantial evidence
is deferential, and “[t]he threshold for such evidentiary
sufficiency is not high.” Biestek, 139 S. Ct at 1154.
Substantial evidence is “more than a mere scintilla” and
means only “such relevant evidence as a reasonable mind
might accept as adequate to support a conclusion.” Id.
(citation omitted). Moreover, our inquiry “defers to the
presiding ALJ, who has seen the hearing up close.” Id. at
1157.

    Given our deferential substantial evidence review, there
is no “categorical rule, applying to every case in which a
vocational expert refuses a request for underlying data,”
which would make an expert’s testimony per se unreliable.

     12
        Ford did not argue to the district court that the ALJ’s failure to
obtain the vocational expert’s underlying data violated her due process
rights; therefore, she forfeited this issue. See United States v. Flores-
Montano, 424 F.3d 1044, 1047 (9th Cir. 2005). In any event, this
argument is meritless. “The fundamental requirement of due process is
the opportunity to be heard ‘at a meaningful time and in a meaningful
manner.’” Mathews v. Eldridge, 424 U.S. 319, 333 (1976) (quoting
Armstrong v. Manzo, 380 U.S. 545, 552 (1965)). Here, Ford had a
meaningful opportunity to present her case to the ALJ, to cross-examine
witnesses, and even to submit rebuttal evidence after her hearing. See
Shaibi v. Berryhill, 883 F.3d 1102, 1110 (9th Cir. 2017). Due process
does not require any further procedural protections in this context. Cf.
Richardson v. Perales, 402 U.S. 389, 402 (1971).
                           FORD V. SAUL                              29

Id. Rather, “the inquiry, as is usually true in determining the
substantiality of evidence, is case-by-case,” id., and the court
must consider the evidence in the record in each individual
case.    In some cases, the “expert’s withholding of
[underlying] data, when combined with other aspects of the
record, will prevent [the expert’s] testimony from qualifying
as substantial evidence.”13 Id. This could occur, for instance,
if the expert’s testimony lacks “markers of reliability,” and
“the expert has no good reason to keep the data private.” Id.
Likewise, the expert’s “withholding of data may count
against” the expert’s opinion, such as where the expert lacked
strong qualifications and offered only “testimony that is so
feeble, or contradicted, that it would fail to clear the
substantial-evidence bar.” Id. at 1155–56. But in many of
cases, where the expert is qualified and presents cogent
testimony that does not conflict with other evidence in the
record, “the expert’s testimony still will clear (even handily
so) the more-than-a-mere-scintilla threshold” even when the
expert declines to provide the underlying data. Id. at 1157.

    Here, the expert’s testimony cleared the low substantial
evidence bar. Ford points to no indicia of unreliability in the
expert’s testimony—she does not argue that the expert lacked
the necessary qualifications, that his testimony was
untrustworthy, or that the testimony was contradicted by


     13
        Although Ford points to a social security handbook that advises
vocational experts to bring the sources supporting their estimates to the
Social Security hearing, see Social Security Administration, Vocational
Expert Handbook, 37 (Aug. 2017), an expert’s failure to comply with such
a best practice does not, without more, make the testimony untrustworthy,
see Biestek, 139 S. Ct. at 1155 (noting that an expert’s unsupported
testimony may constitute substantial evidence even though the expert’s
“testimony would be even better” if the expert had produced supporting
data, which is a “best practice for the SSA and its experts”).
30                           FORD V. SAUL

other evidence in the record.14 Moreover, unlike the expert in
Biestek, the expert here did not decline to supply his
underlying sources; rather, he merely stated that he did not
have the information in his notes. Ford does not contend that
the vocational expert’s estimate is in “obvious or apparent”
conflict with estimates provided in the Dictionary of
Occupational Titles (DOT), see Lamear v. Berryhill, 865 F.3d
1201, 1205 (9th Cir. 2017), or contradicts the Medical-
Vocational Guidelines, see Swenson v. Sullivan, 876 F.2d
683, 689 (9th Cir. 1989), which would oblige the ALJ to sua
sponte investigate and resolve the conflict. Indeed, Ford fails
to identify any ambiguity or gap in the expert’s testimony,
and so the ALJ’s duty to develop the record was not
triggered. Cf. Mayes, 276 F.3d at 459–60.

    Ford does not identify any evidence undermining the
vocational expert’s testimony. We have long held that “in the
absence of any contrary evidence, a [vocational expert’s]
testimony is one type of job information that is regarded as
inherently reliable; thus, there is no need for an ALJ to assess


     14
        Contrary to Ford’s argument that without access to the expert’s
methodology and data she cannot rebut the expert’s testimony, Ford could
have challenged the expert’s testimony in several ways. A claimant may
challenge evidence on the ground that it conflicts with the DOT or the
Medical-Vocational Guidelines, or on the ground that it differs from those
provided by the County Business Patterns (CBP) or Occupational Outlook
Handbook (OOH). The ALJ must consider the weight of such challenges
as it makes its finding at step five. See Shaibi, 883 F.3d at 1110.
Alternatively, a claimant may request to “submit supplemental briefing or
interrogatories contrasting the [vocational expert]’s specific job estimates
with estimates of the claimant’s own.” Id. If the ALJ declines this
request, “the claimant may raise new evidence . . . before the Appeals
Council, provided that evidence is both relevant and ‘relates to the period
on or before the ALJ’s decision.’” Id. (quoting Brewes v. Comm’r of Soc.
Sec. Admin., 682 F.3d 1157, 1162 (9th Cir. 2012)).
                        FORD V. SAUL                         31

its reliability.” Buck v. Berryhill, 869 F.3d 1040, 1051 (9th
Cir. 2017). Given its inherent reliability, a qualified
vocational expert’s testimony as to the number of jobs
existing in the national economy that a claimant can perform
is ordinarily sufficient by itself to support an ALJ’s step-five
finding. See Tackett, 180 F.3d at 1100 (“[T]he Commissioner
[can] meet the burden of showing that there is other work in
‘significant’ numbers in the national economy that [a]
claimant can perform . . . by the testimony of a vocational
expert.”) (citation omitted); Barker v. Sec’y of Health and
Human Servs., 882 F.2d 1474, 1479–80 (9th Cir. 1989).
Therefore, we conclude that the expert’s testimony here is
“the kind of evidence—far more than a mere scintilla—that
a reasonable mind might accept as adequate to support a
finding about job availability.” Biestek, 139 S. Ct. at 1155
(cleaned up). Accordingly, we affirm the ALJ’s conclusion
at step five.

   AFFIRMED.
