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Katherine A Warner, OD

Optometry · Stanford

NPI 1750418075

Medicare standing
Clear
Enrolled, allowed to bill and order, not excluded
Plans that list them
Not verified
Not the same as out of network.
Offices
2

Offices

2 locations · Stanford Health Care · 3,152 clinicians in this group

Looking this up.

Hospitals listed: Stanford Health Care. That is not proof they admit you there this week.

Plan participation

Not verified

We could not verify current plan participation for this doctor. This does not mean they are out of network. Call Dr. Warner’s office to ask if they take your plan before you enroll.

Hospitals they work in

1 hospital

These rate the hospital, not this clinician. Most measures at most hospitals are no different from the national rate.

  • Stanford Health CareStanford, CAAcute Care Hospital · Voluntary non-profit - Private · Has an emergency departmentPart of Stanford Health Care, which runs 3 hospitalsHome of Stanford Cancer Institute, a National Cancer Institute designated comprehensive cancer centrePatients rate it 4 of 5 · 83% would definitely recommend it
    Overall rating: 5 of 5 starsWorse than the national rate — Perioperative pulmonary embolism or deep vein thrombosis rate: 5.31 (4.24 to 6.37) · 8,661 cases, Jul 2022 – Jun 2024Worse than the national rate — Rate of inpatient admissions for patients receiving outpatient chemotherapy: 14.1 (12.7 to 15.7) · 2,191 cases, Jan 2024 – Dec 2024Better than the national rate — Postoperative respiratory failure rate: 4.08 (1.95 to 6.21) · 5,296 cases, Jul 2022 – Jun 2024Better than the national rate — Catheter Associated Urinary Tract Infections (ICU + select Wards): 0.317, Oct 2024 – Sep 2025Better than the national rate — Clostridium Difficile (C.Diff): 0.446, Oct 2024 – Sep 2025Better than the national rate — SSI - Colon Surgery: 0.241, Oct 2024 – Sep 2025Better than the national rate — Ratio of unplanned hospital visits after hospital outpatient surgery: 0.7 (0.6 to 0.9) · 3,348 cases, Jan 2024 – Dec 2024
See every measure and the patient survey for Stanford Health Care

Behind the star rating — Deaths: 5 better, 3 the same, 0 worse of 8 measures. Safety: 3 better, 5 the same, 0 worse of 8 measures. Readmissions: 2 better, 5 the same, 4 worse of 11 measures. The star rating is worked out from an earlier period than the measures below, so the two can disagree.

Every scored measure at Stanford Health Care
Perioperative pulmonary embolism or deep vein thrombosis rateComplications and deaths5.31 (4.24 to 6.37) · 8,661 casesWorseJul 2022 – Jun 2024
Rate of inpatient admissions for patients receiving outpatient chemotherapyUnplanned return visits14.1 (12.7 to 15.7) · 2,191 casesWorseJan 2024 – Dec 2024
Postoperative respiratory failure rateComplications and deaths4.08 (1.95 to 6.21) · 5,296 casesBetterJul 2022 – Jun 2024
Catheter Associated Urinary Tract Infections (ICU + select Wards)Infections0.317BetterOct 2024 – Sep 2025
Clostridium Difficile (C.Diff)Infections0.446BetterOct 2024 – Sep 2025
SSI - Colon SurgeryInfections0.241BetterOct 2024 – Sep 2025
Ratio of unplanned hospital visits after hospital outpatient surgeryUnplanned return visits0.7 (0.6 to 0.9) · 3,348 casesBetterJan 2024 – Dec 2024
Abdominopelvic accidental puncture or laceration rateComplications and deaths1.06 (0.45 to 1.67) · 5,374 casesNo differentJul 2022 – Jun 2024
CMS Medicare PSI 90: Patient safety and adverse events compositeComplications and deaths0.86 (0.72 to 1)No differentJul 2022 – Jun 2024
Death rate among surgical inpatients with serious treatable complicationsComplications and deaths166.09 (137.88 to 194.3) · 470 casesNo differentJul 2022 – Jun 2024
Death rate for CABG surgery patientsComplications and deaths1.1 · 192 casesNoneJul 2022 – Jun 2025
Death rate for COPD patientsComplications and deaths6.4 · 146 casesNoneJul 2022 – Jun 2025
Death rate for heart attack patientsComplications and deaths9.7 · 253 casesNoneJul 2022 – Jun 2025
Death rate for heart failure patientsComplications and deaths6.3 · 880 casesNoneJul 2022 – Jun 2025
Death rate for pneumonia patientsComplications and deaths10.3 · 935 casesNoneJul 2022 – Jun 2025
Death rate for stroke patientsComplications and deaths8.7 · 501 casesNoneJul 2023 – Jun 2025
Hybrid Hospital-Wide All-Cause Risk Standardized Mortality RateComplications and deaths2.1 · 7,730 casesNoneJul 2024 – Jun 2025
Iatrogenic pneumothorax rateComplications and deaths0.13 (0 to 0.27) · 20,799 casesNo differentJul 2022 – Jun 2024
In-hospital fall-associated fracture rateComplications and deaths0.28 (0.14 to 0.43) · 23,182 casesNo differentJul 2022 – Jun 2024
Postoperative acute kidney injury requiring dialysis rateComplications and deaths0.94 (0.2 to 1.68) · 5,694 casesNo differentJul 2022 – Jun 2024
Postoperative hemorrhage or hematoma rateComplications and deaths2.36 (1.54 to 3.19) · 7,846 casesNo differentJul 2022 – Jun 2024
Postoperative sepsis rateComplications and deaths5.2 (3.76 to 6.64) · 5,603 casesNo differentJul 2022 – Jun 2024
Postoperative wound dehiscence rateComplications and deaths1.38 (0.23 to 2.53) · 2,211 casesNo differentJul 2022 – Jun 2024
Pressure ulcer rateComplications and deaths0.52 (0.21 to 0.83) · 19,915 casesNo differentJul 2022 – Jun 2024
Rate of complications for hip/knee replacement patientsComplications and deaths3.6 · 416 casesNoneApr 2023 – Mar 2025
Central Line Associated Bloodstream Infection (ICU + select Wards)Infections0.869No differentOct 2024 – Sep 2025
MRSA BacteremiaInfections0.857No differentOct 2024 – Sep 2025
SSI - Abdominal HysterectomyInfections0.368No differentOct 2024 – Sep 2025
Acute Myocardial Infarction (AMI) 30-Day Readmission RateUnplanned return visits16.2 · 247 casesNoneJul 2023 – Jun 2025
Heart failure (HF) 30-Day Readmission RateUnplanned return visits20.5 · 1,021 casesNoneJul 2023 – Jun 2025
Hospital return days for heart attack patientsUnplanned return visits47.8 · 258 casesNoneJul 2022 – Jun 2025
Hospital return days for heart failure patientsUnplanned return visits-1.6 · 990 casesNoneJul 2022 – Jun 2025
Hospital return days for pneumonia patientsUnplanned return visits20.8 · 976 casesNoneJul 2022 – Jun 2025
Pneumonia (PN) 30-Day Readmission RateUnplanned return visits16.5 · 959 casesNoneJul 2023 – Jun 2025
Rate of emergency department (ED) visits for patients receiving outpatient chemotherapyUnplanned return visits5.2 (4.4 to 6.2) · 2,191 casesNo differentJan 2024 – Dec 2024
Rate of readmission after hip/knee replacementUnplanned return visits5.1 · 425 casesNoneJul 2023 – Jun 2025
Rate of readmission for CABGUnplanned return visits9.6 · 158 casesNoneJul 2023 – Jun 2025
Rate of readmission for chronic obstructive pulmonary disease (COPD) patientsUnplanned return visits19.6 · 183 casesNoneJul 2023 – Jun 2025
Rate of unplanned hospital visits after colonoscopy (per 1,000 colonoscopies)Unplanned return visits12.7 (10.4 to 15.4) · 4,578 casesNo differentJan 2022 – Dec 2024

What patients said (6,810 patients answered, 25% of those asked)

Patient survey stars by topic at Stanford Health Care
Cleanliness4
Nurse communication4
Doctor communication4
Communication about medicines3
Discharge information4
Overall hospital rating4
Quietness2
Recommend hospital5
Share of patients giving the best answer at Stanford Health Care
Room was "always" clean75%
Nurses "always" communicated well82%
Doctors "always" communicated well81%
Staff "always" explained63%
Yes, staff "did" give patients this information89%
Yes, staff "did" give patients information about help after discharge89%
Doctors "always" explained things so they could understand76%
Doctors "always" listened carefully80%
Doctors "always" treated them with courtesy and respect87%
Patients who gave a rating of "9" or "10" (high)79%
Staff "always" explained new medications76%
Nurses "always" explained things so they could understand77%
Nurses "always" listened carefully79%
Nurses "always" treated them with courtesy and respect88%
"Always" quiet at night53%
"YES", patients would definitely recommend the hospital83%
Staff "always" explained possible side effects50%
Yes, staff "did" give patients information about possible symptoms90%

Original Medicare doctor bills

$27,880

Medicare paid this office $27,880 for 484 people.

This is what Medicare paid the clinician — not Medicare Advantage, and not the pharmacy.

Largest Original Medicare bills
Established patient problem focused exam of visual system200$9,751$43
Established patient complete exam of visual system119$7,482$62
New patient complete exam of visual system62$4,420$71
New patient problem focused exam of visual system111$4,326$39
Exam of visual field with extended testing31$725$23
See all 7 services
Every Original Medicare service billed
Established patient problem focused exam of visual system200$9,751$43
Established patient complete exam of visual system119$7,482$62
New patient complete exam of visual system62$4,420$71
New patient problem focused exam of visual system111$4,326$39
Exam of visual field with extended testing31$725$23
Imaging of optic nerve42$715$17
Ct scan of cornea17$307$18

Who their Medicare patients are

484 Original Medicare patients in 2024. Average age 74 · Under 65 7% · 85 and older 12% · Women 66% · Also on Medicaid 24% · Health risk score 1.17. Above the middle of the specialty; the typical optometry clinician is at 0.97.

Conditions among them: High blood pressure 62% · Diabetes 28% · Coronary heart disease 22% · Chronic kidney disease 17% · Depression 16% · Cancer 15% · Atrial fibrillation 13% · Heart failure 12% · COPD 9% · Stroke 7% · Dementia 5%.

The office billed $107,829, Medicare allowed $39,233 and paid $27,880; for 618 services of 10 kinds.

Original Medicare patients only. A risk score of 1.0 is the average Medicare patient; higher means sicker. Any count under 11 is hidden.

Year by year

Original Medicare by year
2024484618741.17$107,829$27,880
2023349464751.10$81,494$21,804
2022380453751.03$77,488$20,296
2021410496751.11$84,879$22,442
2020308404741.03$62,519$17,460
2019360471741.16$72,726$22,802
2018337434751.18$67,510$20,507
2017296381731.18$60,512$17,624
2016281400741.07$66,170$18,493
2015239314731.08$54,654$16,089
2014269358711.15$63,765$18,202
2013216266710.90$48,861$13,757

Original Medicare only. A service billed for fewer than 11 people in a year is hidden, so the lines can add up to less than the year's total.

See the services billed each year

2023: 7 services

Original Medicare services billed in 2023
Established patient problem focused exam of visual system137$6,995$46
Established patient complete exam of visual system90$5,916$66
New patient complete exam of visual system48$3,646$76
New patient problem focused exam of visual system83$3,466$42
Imaging of optic nerve42$799$19
Exam of visual field with extended testing23$515$22
Ct scan of cornea15$242$16

2022: 6 services

Original Medicare services billed in 2022
Established patient problem focused exam of visual system167$8,091$45
Established patient complete exam of visual system83$4,764$57
New patient problem focused exam of visual system107$4,220$39
New patient complete exam of visual system35$2,391$68
Imaging of optic nerve22$356$16
Ct scan of cornea14$208$15

2021: 6 services

Original Medicare services billed in 2021
Established patient problem focused exam of visual system186$9,111$44
New patient problem focused exam of visual system117$4,873$42
Established patient complete exam of visual system73$4,406$60
New patient complete exam of visual system40$2,964$74
Imaging of optic nerve26$443$17
Exam of visual field with extended testing13$287$22

2020: 6 services

Original Medicare services billed in 2020
Established patient problem focused exam of visual system175$9,280$45
Established patient complete exam of visual system73$4,327$58
New patient complete exam of visual system26$1,710$66
New patient problem focused exam of visual system42$1,164$28
Imaging of optic nerve26$431$17
Exam of visual field with extended testing17$322$19

2019: 6 services

Original Medicare services billed in 2019
Established patient problem focused exam of visual system159$8,255$45
Established patient complete exam of visual system86$5,638$64
New patient complete exam of visual system55$4,466$81
New patient problem focused exam of visual system77$3,115$40
Imaging of optic nerve26$520$19
Exam of visual field with extended testing22$516$22

2018: 6 services

Original Medicare services billed in 2018
Established patient problem focused exam of visual system141$7,082$42
Established patient complete exam of visual system92$5,782$63
New patient complete exam of visual system60$4,165$69
New patient problem focused exam of visual system53$2,242$42
Imaging of optic nerve26$469$18
Exam of visual field with extended testing16$304$17

2017: 6 services

Original Medicare services billed in 2017
Established patient problem focused exam of visual system130$6,609$44
Established patient complete exam of visual system92$5,639$61
New patient complete exam of visual system35$2,391$68
New patient problem focused exam of visual system43$1,862$43
Exam of visual field with extended testing19$469$22
Imaging of optic nerve22$316$14

2016: 7 services

Original Medicare services billed in 2016
Established patient problem focused exam of visual system141$7,568$44
Established patient complete exam of visual system106$6,574$60
New patient complete exam of visual system27$1,924$71
Imaging of optic nerve30$686$22
New patient problem focused exam of visual system15$658$44
Exam of visual field with extended testing24$623$26
Ct scan of cornea14$281$18

2015: 6 services

Original Medicare services billed in 2015
Established patient complete exam of visual system84$5,363$63
Established patient problem focused exam of visual system102$5,288$45
New patient complete exam of visual system49$4,008$82
Imaging of optic nerve18$444$25
Exam of visual field with extended testing16$390$23
Ct scan of cornea16$244$15

2014: 5 services

Original Medicare services billed in 2014
Established patient complete exam of visual system91$5,810$63
New patient complete exam of visual system71$5,288$74
Established patient problem focused exam of visual system102$5,259$44
Exam of visual field with extended testing28$654$22
Imaging of optic nerve21$480$23

2013: 5 services

Original Medicare services billed in 2013
New patient complete exam of visual system58$4,458$77
Established patient complete exam of visual system72$4,404$61
Established patient problem focused exam of visual system83$3,756$43
Imaging of optic nerve19$415$22
Exam of visual field with extended testing17$409$23

Medicaid work

$2,645 in 2024

Medicaid paid $2,645 for 209 billed services this clinician did in 2024, up to 28 people in a month for one service.

Medicaid and CHIP claims where this clinician did the service, fee-for-service and managed care together. Any month with fewer than 11 patients is hidden, so small Medicaid practices undercount.

Largest Medicaid services in 2024
DETERMINATION REFRACTIVE STATE128$1,087
INTRM OPH EXAM NEW PATIENT40$849
Ophthalmological services: medical examination and evaluation, with initiation or continuation of diagnostic and treatment program; intermediate, established patient41$709
Medicaid work by year
2024209328$2,645
2023133320$1,650
2022116219$1,060
202197329$1,001
202058117$393
2019133121$865
2018148122$1,102
See the largest Medicaid services in earlier years

2023

Largest Medicaid services in 2023
DETERMINATION REFRACTIVE STATE107$977
INTRM OPH EXAM NEW PATIENT12$385
Ophthalmological services: medical examination and evaluation, with initiation or continuation of diagnostic and treatment program; intermediate, established patient14$289

2022

Largest Medicaid services in 2022
DETERMINATION REFRACTIVE STATE91$707
Ophthalmological services: medical examination and evaluation, with initiation or continuation of diagnostic and treatment program; intermediate, established patient25$353

2021

Largest Medicaid services in 2021
DETERMINATION REFRACTIVE STATE73$528
Ophthalmological services: medical examination and evaluation, with initiation or continuation of diagnostic and treatment program; intermediate, established patient12$263
INTRM OPH EXAM NEW PATIENT12$210

2020

Largest Medicaid services in 2020
DETERMINATION REFRACTIVE STATE58$393

2019

Largest Medicaid services in 2019
DETERMINATION REFRACTIVE STATE133$865

2018

Largest Medicaid services in 2018
DETERMINATION REFRACTIVE STATE148$1,102

Drugs they prescribed that Part D paid

$20,782

Pharmacies billed $20,782 in 2024.

This is pharmacy cost, not the office bill, and not what patients paid.

Opioids were 0% of their Part D prescriptions (0 of 47) in 2024. Too few prescriptions to compare fairly with other clinicians.

0 generic and 47 brand-name prescriptions · $20,782 in drug cost.

Part D prescriptions only. The opioid rate is opioid prescriptions as a share of all this clinician's Part D prescriptions; surgeons and pain specialists run higher than others, so it is shown against the same specialty.

Largest Part D drug costs
Xiidra16$11,041$690
Cyclosporine22$2,887$131

Year by year

Part D prescribing by year
202447140% (0)100%$20,782
202382290% (0)29%$17,092
202280240% (0)44%$27,102
2021115330% (0)54%$28,234
2020110320% (0)66%$18,005
2019108400% (0)66%$22,617
201885250% (0)42%$11,428
201785290% (0)35%$11,373
201666260% (0)56%$11,028
201575300% (0)72%$14,094
201453200% (0)89%$7,609
201335140% (0)83%$4,920

Part D prescriptions only. A drug prescribed to fewer than 11 people in a year is hidden.

See the drugs prescribed each year

2023: 2 drugs

Part D drugs prescribed in 2023
Restasis15$11,745$783
Olopatadine50$864$17

2022: 3 drugs

Part D drugs prescribed in 2022
Restasis20$16,370$818
Xiidra15$9,803$654
Olopatadine40$814$20

2021: 3 drugs

Part D drugs prescribed in 2021
Restasis19$12,813$674
Xiidra20$12,090$605
Olopatadine65$1,591$24

2020: 2 drugs

Part D drugs prescribed in 2020
Restasis19$9,932$523
Olopatadine72$2,236$31

2019: 2 drugs

Part D drugs prescribed in 2019
Xiidra17$9,153$538
Olopatadine62$3,677$59

2018: 2 drugs

Part D drugs prescribed in 2018
Xiidra14$7,588$542
Olopatadine56$2,574$46

2017: 1 drug

Part D drugs prescribed in 2017
Olopatadine53$2,474$47

2016: 2 drugs

Part D drugs prescribed in 2016
Pataday14$2,261$162
Olopatadine30$2,178$73

2015: 2 drugs

Part D drugs prescribed in 2015
Patanol38$10,436$275
Pataday13$2,051$158

2014: 1 drug

Part D drugs prescribed in 2014
Patanol37$6,018$163

2013: 1 drug

Part D drugs prescribed in 2013
Patanol18$3,237$180

Money from drug and device companies

$88 in 2024

Industry payments by year
202411None$88
202011None$21
201911None$124

Paid work is consulting, speaking, honoraria and royalties, as opposed to meals and travel.

A payment is not proof that care is biased.

Payments by company
CooperVisionSynergeyes Contact Lens$88
1 payment
  • Meals for Synergeyes Contact Lens · 2024-01-25 · $88
See the published payment
Every published payment
CooperVisionMeals · 2024-01-25Synergeyes Contact Lens$88
See earlier years (2020, 2019)

2020: $21

Payments by company in 2020
Johnson & Johnson Vision CareAcuvue$21
1 payment
  • Meals for Acuvue · 2020-12-08 · $21

2019: $124

Payments by company in 2019
AllerganRestasis$124
1 payment
  • Meals for Restasis · 2019-02-28 · $124

Checkups this office reported

Medicare did not publish checkup rates for this clinician.

Medicare’s overall office score
76.5 / 100
Scores the office’s reporting and systems. It is not a grade for how the doctor treats you.

Professional record

NPI
1750418075
Licence
CA SD11448
Gender
Female
More record details
Sole proprietor
No
Medicaid ID
CA SD0114480
Taxonomy
Federal specialty code 152W00000X (152W00000X)
Mailing address
300 Pasteur Dr, Stanford, CA, 94305
NPI first listed
2007-02-27
NPI last updated
2019-03-19

This is when the NPI record was last certified, not a medical board exam.