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Gerald Diaz, MD

Internal Medicine · San Jose

NPI 1669784443

Medicare standing
Clear
Enrolled, allowed to bill and order, not excluded
Plans that list them
Not verified
Not the same as out of network.
Office
1

Offices

1 location · County of Santa Clara · 1,000 clinicians in this group

Looking this up.

Hospitals listed: Santa Clara Valley Medical Center. 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. Diaz’s office at (408) 885-5000 to ask if they take your plan before you enroll.

California Medical Board record

Licence A126359 · Current

Licensed to practise in California · since 2013 · expires 2028-09-30 · Saint Louis University School of Medicine.

No disciplinary actions, convictions, malpractice judgments or citations in this record.

Checkups this office reported

Medicare did not publish checkup rates for this clinician.

Medicare’s overall office score
80.6 / 100
Scores the office’s reporting and systems. It is not a grade for how the doctor treats you.

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.

  • Santa Clara Valley Medical CenterSan Jose, CAAcute Care Hospital · Government - Local · Has an emergency department · Birthing-friendlyPart of Santa Clara Valley Health and Hospital System, which runs 3 hospitalsPatients rate it 3 of 5 · 70% would definitely recommend it
    Overall rating: 2 of 5 starsWorse than the national rate — SSI - Colon Surgery: 2.572, Oct 2024 – Sep 2025Better than the national rate — Central Line Associated Bloodstream Infection (ICU + select Wards): 0.563, Oct 2024 – Sep 2025Better than the national rate — Clostridium Difficile (C.Diff): 0.256, Oct 2024 – Sep 2025Better than the national rate — MRSA Bacteremia: 0.369, Oct 2024 – Sep 2025
See every measure and the patient survey for Santa Clara Valley Medical Center

Behind the star rating — Deaths: 2 better, 6 the same, 0 worse of 8 measures. Safety: 2 better, 5 the same, 1 worse of 8 measures. Readmissions: 0 better, 10 the same, 1 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 Santa Clara Valley Medical Center
SSI - Colon SurgeryInfections2.572WorseOct 2024 – Sep 2025
Central Line Associated Bloodstream Infection (ICU + select Wards)Infections0.563BetterOct 2024 – Sep 2025
Clostridium Difficile (C.Diff)Infections0.256BetterOct 2024 – Sep 2025
MRSA BacteremiaInfections0.369BetterOct 2024 – Sep 2025
Abdominopelvic accidental puncture or laceration rateComplications and deaths1.25 (0.3 to 2.2) · 1,535 casesNo differentJul 2022 – Jun 2024
CMS Medicare PSI 90: Patient safety and adverse events compositeComplications and deaths1.07 (0.76 to 1.38)No differentJul 2022 – Jun 2024
Death rate among surgical inpatients with serious treatable complicationsComplications and deaths214.59 (167.38 to 261.8) · 108 casesNo differentJul 2022 – Jun 2024
Death rate for CABG surgery patientsComplications and deaths2.8 · 41 casesNoneJul 2022 – Jun 2025
Death rate for COPD patientsComplications and deaths6 · 141 casesNoneJul 2022 – Jun 2025
Death rate for heart attack patientsComplications and deaths10.2 · 124 casesNoneJul 2022 – Jun 2025
Death rate for heart failure patientsComplications and deaths8.3 · 501 casesNoneJul 2022 – Jun 2025
Death rate for pneumonia patientsComplications and deaths14.9 · 653 casesNoneJul 2022 – Jun 2025
Death rate for stroke patientsComplications and deaths10.1 · 348 casesNoneJul 2023 – Jun 2025
Hybrid Hospital-Wide All-Cause Risk Standardized Mortality RateComplications and deaths3 · 4,502 casesNoneJul 2024 – Jun 2025
Iatrogenic pneumothorax rateComplications and deaths0.24 (0.04 to 0.43) · 9,014 casesNo differentJul 2022 – Jun 2024
In-hospital fall-associated fracture rateComplications and deaths0.34 (0.15 to 0.52) · 9,216 casesNo differentJul 2022 – Jun 2024
Perioperative pulmonary embolism or deep vein thrombosis rateComplications and deaths4.54 (2.51 to 6.58) · 1,421 casesNo differentJul 2022 – Jun 2024
Postoperative acute kidney injury requiring dialysis rateComplications and deaths1.54 (0 to 3.2) · 288 casesNo differentJul 2022 – Jun 2024
Postoperative hemorrhage or hematoma rateComplications and deaths2.11 (0.66 to 3.56) · 1,446 casesNo differentJul 2022 – Jun 2024
Postoperative respiratory failure rateComplications and deaths11.61 (4.09 to 19.14) · 294 casesNo differentJul 2022 – Jun 2024
Postoperative sepsis rateComplications and deaths7.29 (3.39 to 11.2) · 299 casesNo differentJul 2022 – Jun 2024
Postoperative wound dehiscence rateComplications and deaths1.9 (0.45 to 3.36) · 333 casesNo differentJul 2022 – Jun 2024
Pressure ulcer rateComplications and deaths0.23 (0 to 0.78) · 7,538 casesNo differentJul 2022 – Jun 2024
Rate of complications for hip/knee replacement patientsComplications and deaths5.4 · 94 casesNoneApr 2023 – Mar 2025
Catheter Associated Urinary Tract Infections (ICU + select Wards)Infections0.735No differentOct 2024 – Sep 2025
SSI - Abdominal HysterectomyInfections2.573No differentOct 2024 – Sep 2025
Acute Myocardial Infarction (AMI) 30-Day Readmission RateUnplanned return visits14.6 · 185 casesNoneJul 2023 – Jun 2025
Heart failure (HF) 30-Day Readmission RateUnplanned return visits22.1 · 951 casesNoneJul 2023 – Jun 2025
Hospital return days for heart attack patientsUnplanned return visits56.3 · 128 casesNoneJul 2022 – Jun 2025
Hospital return days for heart failure patientsUnplanned return visits6.4 · 644 casesNoneJul 2022 – Jun 2025
Hospital return days for pneumonia patientsUnplanned return visits1.3 · 699 casesNoneJul 2022 – Jun 2025
Pneumonia (PN) 30-Day Readmission RateUnplanned return visits16.3 · 921 casesNoneJul 2023 – Jun 2025
Rate of emergency department (ED) visits for patients receiving outpatient chemotherapyUnplanned return visits5.7 (3.9 to 8.1) · 226 casesNo differentJan 2024 – Dec 2024
Rate of inpatient admissions for patients receiving outpatient chemotherapyUnplanned return visits12.6 (9.4 to 16.5) · 226 casesNo differentJan 2024 – Dec 2024
Rate of readmission after hip/knee replacementUnplanned return visits5.4 · 94 casesNoneJul 2023 – Jun 2025
Rate of readmission for CABGUnplanned return visits11.4 · 54 casesNoneJul 2023 – Jun 2025
Rate of readmission for chronic obstructive pulmonary disease (COPD) patientsUnplanned return visits20.3 · 242 casesNoneJul 2023 – Jun 2025
Rate of unplanned hospital visits after colonoscopy (per 1,000 colonoscopies)Unplanned return visits13.2 (9.9 to 17.4) · 702 casesNo differentJan 2022 – Dec 2024
Ratio of unplanned hospital visits after hospital outpatient surgeryUnplanned return visits1 (0.7 to 1.4) · 195 casesNo differentJan 2024 – Dec 2024

What patients said (4,032 patients answered, 29% of those asked)

Patient survey stars by topic at Santa Clara Valley Medical Center
Cleanliness3
Nurse communication3
Doctor communication3
Communication about medicines3
Discharge information2
Overall hospital rating3
Quietness2
Recommend hospital4
Share of patients giving the best answer at Santa Clara Valley Medical Center
Room was "always" clean70%
Nurses "always" communicated well73%
Doctors "always" communicated well76%
Staff "always" explained57%
Yes, staff "did" give patients this information82%
Yes, staff "did" give patients information about help after discharge82%
Doctors "always" explained things so they could understand71%
Doctors "always" listened carefully74%
Doctors "always" treated them with courtesy and respect82%
Patients who gave a rating of "9" or "10" (high)67%
Staff "always" explained new medications71%
Nurses "always" explained things so they could understand71%
Nurses "always" listened carefully69%
Nurses "always" treated them with courtesy and respect80%
"Always" quiet at night43%
"YES", patients would definitely recommend the hospital70%
Staff "always" explained possible side effects44%
Yes, staff "did" give patients information about possible symptoms83%

Original Medicare doctor bills

$63,093

Medicare paid this office $63,093 for 418 people.

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

Largest Original Medicare bills
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes343$44,082$69
Hospital discharge day management, more than 30 minutes108$11,192$104
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes42$4,809$115
Subsequent hospital care with straightforward or low level of medical decision making, per day at least 25 minutes18$972$40

Who their Medicare patients are

418 Original Medicare patients in 2024. Average age 75 · Under 65 14% · 85 and older 20% · Women 45% · Also on Medicaid 75% · Health risk score 3.14. Sicker patients than 9 in 10 peers; the typical internal medicine clinician is at 1.76.

Conditions among them: High blood pressure 75% · Diabetes 59% · Coronary heart disease 47% · Heart failure 47% · Chronic kidney disease 47% · Atrial fibrillation 38% · Depression 35% · COPD 33% · Dementia 32% · Stroke 25% · Cancer 16%.

The office billed $648,601, Medicare allowed $81,471 and paid $63,093; for 837 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
2024418837753.14$648,601$63,093
20234321,105742.87$782,391$86,024
2022356817742.68$702,881$79,205
2021332759762.61$590,810$70,343
2020196530722.57$363,189$43,225
2019219591693.81$248,689$48,740
2018302947723.70$317,220$80,906
2017290830703.34$278,750$72,818
2016107336693.39$100,406$27,250

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: 4 services

Original Medicare services billed in 2023
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes332$56,940$76
Hospital discharge day management, more than 30 minutes136$14,916$109
Subsequent hospital care with straightforward or low level of medical decision making, per day at least 25 minutes94$7,026$45
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes54$6,336$117

2022: 6 services

Original Medicare services billed in 2022
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes236$45,468$108
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes107$14,724$73
Hospital discharge day management, more than 30 minutes90$10,192$113
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes25$3,559$132
Hospital observation care on day of discharge17$1,347$75
Subsequent hospital care with straightforward or low level of medical decision making, per day at least 25 minutes22$1,282$40

2021: 6 services

Original Medicare services billed in 2021
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes153$26,447$74
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes112$20,376$113
Hospital discharge day management, more than 30 minutes90$10,356$115
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes46$6,827$145
Hospital observation care on day of discharge26$2,105$81
Subsequent hospital care with straightforward or low level of medical decision making, per day at least 25 minutes15$831$36

2020: 4 services

Original Medicare services billed in 2020
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes132$26,200$74
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes45$6,660$148
Hospital discharge day management, more than 30 minutes47$5,127$109
Subsequent hospital care with straightforward or low level of medical decision making, per day at least 25 minutes12$1,443$38

2019: 8 services

Original Medicare services billed in 2019
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes69$16,861$85
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes57$11,395$63
Initial hospital care with moderate level of medical decision making at least 75 minutes39$6,448$165
Hospital discharge day management, more than 30 minutes39$3,555$91
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes24$2,866$119
Hospital discharge day management, 30 minutes or less28$1,643$57
Initial hospital care with straightforward or low level of medical decision making, per day at least 40 minutes11$864$79
Hospital observation care on day of discharge12$792$66

2018: 8 services

Original Medicare services billed in 2018
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes170$44,617$85
Hospital discharge day management, more than 30 minutes108$9,728$88
Initial hospital care with moderate level of medical decision making at least 75 minutes52$8,745$165
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes29$6,436$59
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes15$1,665$111
Follow-up observation care per day, typically 35 minutes13$1,456$86
Hospital discharge day management, 30 minutes or less16$959$60
Hospital observation care on day of discharge13$779$60

2017: 7 services

Original Medicare services billed in 2017
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes117$31,860$84
Initial hospital care with moderate level of medical decision making at least 75 minutes81$13,464$164
Hospital discharge day management, more than 30 minutes80$7,112$88
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes34$5,685$59
Initial hospital care with straightforward or low-level medical decision making at least 55 minutes36$3,898$108
Hospital discharge day management, 30 minutes or less26$1,540$59
Initial hospital care with straightforward or low level of medical decision making, per day at least 40 minutes15$1,225$82

2016: 3 services

Original Medicare services billed in 2016
Subsequent hospital care with moderate levelof medical decision making at least 50 minutes71$17,358$84
Hospital discharge day management, more than 30 minutes43$3,758$87
Subsequent hospital care with moderate levelof medical decision making at least 35 minutes13$2,455$58

Medicaid work

$12,693 in 2024

Medicaid paid $12,693 for 1,182 billed services this clinician did in 2024, up to 77 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
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES1,015$9,984
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter167$2,709
Medicaid work by year
20241,182277$12,693
20231,540498$15,532
20221,102372$19,941
2021888452$16,856
2020824339$13,858
2019343335$5,933
201819113$831
See the largest Medicaid services in earlier years

2023

Largest Medicaid services in 2023
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES1,106$10,728
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter209$3,013
SBSQ HOSPITAL IP/OBS CARE SF/LOW MDM 25 MINUTES211$1,494
1ST HOSPITAL IP/OBS CARE MODERATE MDM 55 MINUTES14$297

2022

Largest Medicaid services in 2022
SBSQ HOSPITAL IP/OBS CARE HIGH MDM 50 MINUTES734$13,454
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter182$3,856
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES186$2,631

2021

Largest Medicaid services in 2021
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES451$7,378
SBSQ HOSPITAL IP/OBS CARE HIGH MDM 50 MINUTES330$7,195
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter78$1,954
1ST HOSPITAL IP/OBS CARE MODERATE MDM 55 MINUTES29$329

2020

Largest Medicaid services in 2020
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES651$10,218
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter133$2,641
1ST HOSPITAL IP/OBS CARE MODERATE MDM 55 MINUTES40$999

2019

Largest Medicaid services in 2019
SBSQ HOSPITAL IP/OBS CARE MOD MDM 35 MINUTES290$4,929
1ST HOSPITAL IP/OBS CARE MODERATE MDM 55 MINUTES26$673
Hospital inpatient or observation discharge day management; more than 30 minutes on the date of the encounter27$331

2018

Largest Medicaid services in 2018
SBSQ HOSPITAL IP/OBS CARE HIGH MDM 50 MINUTES19$831

Drugs they prescribed that Part D paid

$31,888

Pharmacies billed $31,888 in 2024.

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

Opioids were 5% of their Part D prescriptions (11 of 247) in 2024. Above the middle of the specialty; the typical internal medicine clinician is at 1%.

181 generic and fewer than 11 brand-name prescriptions · $31,888 in drug cost · 29 antibiotic prescriptions to 25 people.

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
Eliquis22$15,091$686
Pantoprazole16$93$6
Metoprolol12$90$7
Atorvastatin15$86$6
Tamsulosin11$52$5

Year by year

Part D prescribing by year
2024247815% (11)None$31,888
20232871205% (13)None$37,389
20222891056% (17)None$25,085
2021202857% (14)None$10,077
202017748NoneNone$16,785
201911137NoneNone$17,014
2018257797% (19)None$16,755
201719770NoneNone$14,679
20167551158% (63)33%$86,830
201581014814% (116)23%$75,137
20144688819% (90)None$37,461
2013972814% (14)None$6,472

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

See the drugs prescribed each year

2023: 5 drugs

Part D drugs prescribed in 2023
Eliquis14$11,941$853
Metoprolol12$160$13
Pantoprazole11$148$13
Furosemide16$129$8
Amlodipine Besylate11$47$4

2022: 3 drugs

Part D drugs prescribed in 2022
Atorvastatin19$232$12
Metoprolol12$212$18
Furosemide12$65$5

2021: 4 drugs

Part D drugs prescribed in 2021
Atorvastatin15$162$11
Pantoprazole11$128$12
Carvedilol11$44$4
Hydrocodone-Acetaminophen11$37$3

2019: 1 drug

Part D drugs prescribed in 2019
Eliquis12$7,468$622

2018: 4 drugs

Part D drugs prescribed in 2018
Atorvastatin17$180$11
Bisoprolol14$126$9
Furosemide22$64$3
Carvedilol13$53$4

2017: 1 drug

Part D drugs prescribed in 2017
Advair Diskus13$4,766$367

2016: 27 drugs

Part D drugs prescribed in 2016
Lantus Solostar16$9,261$579
Lantus15$3,812$254
Incruse Ellipta11$2,984$271
Dexilant12$2,728$227
Hydrocodone-Acetaminophen45$1,299$29
Voltaren13$1,053$81
Potassium Chloride19$881$46
Proair Hfa13$717$55
Bd Ultra-Fine Pen Needle18$683$38
Polyethylene Glycol 335017$662$39
Levothyroxine20$451$23
Metoprolol13$408$31
Insulin13$395$30
Valsartan16$392$25
Atorvastatin27$386$14
Gabapentin14$195$14
Tamsulosin12$137$11
Omeprazole14$131$9
Fluticasone Propionate14$131$9
Carvedilol33$130$4
Losartan18$118$7
Pantoprazole16$116$7
Hydrochlorothiazide13$69$5
Furosemide32$55$2
Metformin17$55$3
Ranitidine12$43$4
Lisinopril11$39$4

2015: 20 drugs

Part D drugs prescribed in 2015
Oxycontin13$9,132$702
Dexilant15$3,035$202
Hydrocodone-Acetaminophen67$2,128$32
Proair Hfa17$857$50
Potassium Chloride28$755$27
Bd Ultra-Fine Pen Needle15$598$40
Metoprolol26$567$22
Hydralazine20$491$25
Atorvastatin44$454$10
Polyethylene Glycol 335014$393$28
Gabapentin16$388$24
Omeprazole14$134$10
Carvedilol20$108$5
Prednisone16$95$6
Amlodipine Besylate17$67$4
Metoprolol11$60$5
Ranitidine14$59$4
Metformin12$53$4
Furosemide14$42$3
Lisinopril13$40$3

2014: 12 drugs

Part D drugs prescribed in 2014
Spiriva14$4,105$293
Hydrocodone-Acetaminophen43$1,310$30
Metoprolol30$705$23
Atorvastatin25$291$12
Gabapentin15$282$19
Hydralazine14$179$13
Omeprazole15$176$12
Levothyroxine11$158$14
Tramadol13$107$8
Famotidine12$74$6
Lisinopril15$52$3
Hydrochlorothiazide11$27$2

Money from drug and device companies

$14 in 2025

Industry payments by year
202511None$14
202212None$38

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
Hologic Sales and ServiceMyosure Tissue Removal Device$14
1 payment
  • Meals for Myosure Tissue Removal Device · 2025-05-17 · $14
See the published payment
Every published payment
Hologic Sales and ServiceMeals · 2025-05-17Myosure Tissue Removal Device$14
See earlier years (2022)

2022: $38

Payments by company in 2022
Integra LifeSciencesIntegra$38
2 payments
  • Meals for Integra · 2022-12-30 · $18
  • Meals for Integra · 2022-12-07 · $21

Professional record

NPI
1669784443
Licence
CA A126359California A126359: Current · expires 2028-09-30
Trained
Saint Louis University School of Medicine, 2010
Gender
Male
More record details
Sole proprietor
No
Taxonomy
Internal medicine (207R00000X)
Mailing address
751 S Bascom Ave, San Jose, CA, 95128
NPI first listed
2010-07-08
NPI last updated
2021-03-18
NPI record certified
2021-03-18

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

Extra NPI addresses: 2799 W. Grand Boulevard, Detroit, MI, 48202