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Tristan Tham Yong Ren, MD

Otolaryngology · Stanford

NPI 1225590979

Medicare standing
Clear
Enrolled, allowed to bill and order, not excluded
Plans that list them
13
2 carriers
Office
1

Offices

1 location · 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.

Plans that list them

13 plans · 2 carriers

A missing listing does not mean out of network. Directories change, and a listing does not cover every office. Call Dr. Ren’s office at (650) 723-4000 to confirm they take your plan. Ask about the office you use, its medical group, referrals and appointments.

13 of 13 plans

Plans whose provider directory lists this clinician
Alignment Health BreathEasy (HMO C-SNP)Alignment Health PlanListedOct 3, 2026
Alignment Health Clarity (HMO C-SNP)Alignment Health PlanListedOct 3, 2026
Alignment Health Harmony (HMO)Alignment Health PlanListedOct 3, 2026
Alignment Health Heart & Diabetes (HMO C-SNP)Alignment Health PlanListedOct 3, 2026
Alignment Health Heart & Diabetes CalPlus (HMO C-SNP)Alignment Health PlanListedOct 3, 2026
Alignment Health Heart & Diabetes Care (HMO C-SNP)Alignment Health PlanListedSep 28, 2026
Alignment Health Heart & Diabetes Choice (HMO C-SNP)Alignment Health PlanListedSep 28, 2026
Alignment Health Honor+ Plan (HMO)Alignment Health PlanListedOct 3, 2026
Alignment Health My Choice CalCare (HMO)Alignment Health PlanListedOct 3, 2026
Alignment Health Silicon (HMO C-SNP)Alignment Health PlanListedOct 3, 2026
Alignment Health smartHMO (HMO)Alignment Health PlanListedOct 3, 2026
Alignment Health the ONE (HMO)Alignment Health PlanListedOct 3, 2026
DualConnect (HMO D-SNP)Santa Clara Family Health PlanListedSep 1, 2026

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

$62,203

Medicare paid this office $62,203 for 172 people.

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

Largest Original Medicare bills
Diagnostic exam of nasal passages using an endoscope39$8,668$197
New patient visit (45+ min)31$4,926$159
New patient visit (30+ min)42$4,405$105
Diagnostic exam of voice box using a flexible endoscope26$3,535$131
New patient visit (45+ min)19$2,272$120
See all 11 services
Every Original Medicare service billed
Diagnostic exam of nasal passages using an endoscope39$8,668$197
New patient visit (45+ min)31$4,926$159
New patient visit (30+ min)42$4,405$105
Diagnostic exam of voice box using a flexible endoscope26$3,535$131
New patient visit (45+ min)19$2,272$120
Return visit (30+ min)17$2,103$124
Long return visit (40+ min)12$1,899$158
Short return visit (20+ min)16$1,323$83
New patient visit (30+ min)16$1,170$73
Removal of impacted ear wax27$1,090$40
Diagnostic exam of voice box using a flexible endoscope11$717$65

Procedures Medicare counted

Procedure volume Medicare published
Skin biopsy1-10None

Who their Medicare patients are

172 Original Medicare patients in 2024. Average age 74 · Under 65 9% · 85 and older 13% · Women 59% · Also on Medicaid 19% · Health risk score 1.09. At or below the middle of the specialty; the typical otolaryngology clinician is at 1.19.

Conditions among them: High blood pressure 66% · Diabetes 28% · Coronary heart disease 26% · Chronic kidney disease 22% · Cancer 16% · Depression 16% · Atrial fibrillation 15% · Heart failure 12% · COPD 12% · Stroke 12%.

The office billed $326,514, Medicare allowed $78,453 and paid $62,203; for 373 services of 40 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.

Drugs they prescribed that Part D paid

$1,714

Pharmacies billed $1,714 in 2024.

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

83 generic and fewer than 11 brand-name prescriptions · $1,714 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
Azelastine17$919$40
Fluticasone Propionate16$195$9

Year by year

Part D prescribing by year
20248451NoneNone$1,714
20231816None0%$183
2022492735% (17)None$859
2021563334% (19)None$1,100
2020432335% (15)None$1,179

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

See the drugs prescribed each year

2022: 1 drug

Part D drugs prescribed in 2022
Oxycodone-Acetaminophen11$33$3

2021: 1 drug

Part D drugs prescribed in 2021
Oxycodone-Acetaminophen13$66$5

Money from drug and device companies

$1,395 in 2025

Industry payments by year
2025315None$1,395
2024324None$1,187

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
Aerin MedicalVivaer Stylus$1,299
11 payments
  • Meals for Vivaer Stylus · 2025-04-01 · $26
  • Travel for Vivaer Stylus · 2025-04-01 · $243
  • Meals for Vivaer Stylus · 2025-04-01 · $38
  • Meals for Vivaer Stylus · 2025-04-01 · $92
  • Meals for Vivaer Stylus · 2025-04-01 · $54
  • Meals for Vivaer Stylus · 2025-04-01 · $76
  • Meals for Vivaer Stylus · 2025-04-01 · $123
  • Meals for Vivaer Stylus · 2025-03-31 · $13
  • Travel for Vivaer Stylus · 2025-03-31 · $303
  • Travel for Vivaer Stylus · 2025-03-31 · $198
  • Travel for Vivaer Stylus · 2025-03-11 · $133
Inspire Medical SystemsInspire$79
3 payments
  • Meals for Inspire · 2025-09-30 · $20
  • Meals for Inspire · 2025-03-04 · $26
  • Meals for Inspire · 2025-01-21 · $33
Smith+NephewHalo$17
1 payment
  • Meals for Halo · 2025-01-16 · $17
See all 15 published payments
Every published payment
Inspire Medical SystemsMeals · 2025-09-30Inspire$20
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$26
Aerin MedicalTravel · 2025-04-01Vivaer Stylus$243
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$38
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$92
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$54
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$76
Aerin MedicalMeals · 2025-04-01Vivaer Stylus$123
Aerin MedicalMeals · 2025-03-31Vivaer Stylus$13
Aerin MedicalTravel · 2025-03-31Vivaer Stylus$303
Aerin MedicalTravel · 2025-03-31Vivaer Stylus$198
Aerin MedicalTravel · 2025-03-11Vivaer Stylus$133
Inspire Medical SystemsMeals · 2025-03-04Inspire$26
Inspire Medical SystemsMeals · 2025-01-21Inspire$33
Smith+NephewMeals · 2025-01-16Halo$17
See earlier years (2024)

2024: $1,187

Payments by company in 2024
Inspire Medical SystemsInspire$837
22 payments
  • Meals for Inspire · 2024-11-19 · $44
  • Travel for Inspire · 2024-04-28 · $0
  • Travel for Inspire · 2024-04-27 · $4
  • Travel for Inspire · 2024-04-26 · $59
  • Travel for Inspire · 2024-04-26 · $4
  • Travel for Inspire · 2024-04-21 · $0
  • Travel for Inspire · 2024-04-20 · $0
  • Travel for Inspire · 2024-04-19 · $1
  • Travel for Inspire · 2024-04-16 · $0
  • Travel for Inspire · 2024-04-15 · $13
  • Travel for Inspire · 2024-04-14 · $23
  • Travel for Inspire · 2024-04-13 · $7
  • Travel for Inspire · 2024-04-13 · $196
  • Travel for Inspire · 2024-04-12 · $0
  • Travel for Inspire · 2024-04-12 · $5
  • Travel for Inspire · 2024-04-11 · $13
  • Travel for Inspire · 2024-04-09 · $15
  • Travel for Inspire · 2024-04-07 · $5
  • Travel for Inspire · 2024-04-06 · $11
  • Travel for Inspire · 2024-04-05 · $9
  • Travel for Inspire · 2024-04-02 · $8
  • Travel for Inspire · 2024-01-29 · $419
Cambridge InterventionalCrf$240
1 payment
  • Meals for Crf · 2024-05-02 · $240
Aerin MedicalVivaer Stylus$110
1 payment
  • Meals for Vivaer Stylus · 2024-10-29 · $110

Professional record

NPI
1225590979
Video visits
Lists video visits
Gender
Male
More record details
Sole proprietor
No
Taxonomy
Otolaryngology (207Y00000X)
Mailing address
300 Pasteur Dr, Stanford, CA, 94305
NPI first listed
2019-04-02
NPI last updated
2024-10-11
NPI record certified
2024-10-11

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

Extra NPI addresses: 801 Welch Rd, Palo Alto, CA, 94304