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Winona M Tan, MD

Obstetrics/Gynecology · Palo Alto

NPI 1003904350

Medicare standing
Clear
Enrolled, allowed to bill and order, not excluded
Plans that list them
14
2 carriers
Offices
3

Offices

3 locations · Sutter Bay Medical Foundation · 3,783 clinicians in this group

Looking this up.

Plans that list them

14 plans · 2 carriers

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

14 of 14 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 Sutter Advantage +More (HMO)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

California Medical Board record

Licence G80084 · Current

Licensed to practise in California · since 1994 · expires 2028-09-30 · University of California San Francisco School of Medicine.

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

Original Medicare doctor bills

$5,222

Medicare paid this office $5,222 for 45 people.

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

Largest Original Medicare bills
Short return visit (20+ min)11$991$76
Cervical or vaginal cancer screening; pelvic and clinical breast examination17$818$48

Who their Medicare patients are

45 Original Medicare patients in 2024. Average age 75 · Women 100% · Health risk score 0.82. At or below the middle of the specialty; the typical obstetrics & gynecology clinician is at 0.88.

Conditions among them: High blood pressure 49%.

The office billed $21,329, Medicare allowed $6,760 and paid $5,222; for 65 services of 15 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
20244565750.82$21,329$5,222
20234054730.53$20,098$5,293
20223744720.56$9,935$2,723
20214886730.69$26,536$7,251
20203974710.78$24,502$6,100
20196193710.74$23,180$5,983
20185884740.76$26,446$6,073
201760100710.77$25,944$6,707
20164573700.93$29,577$7,486
201571128700.93$38,639$10,485
20145376690.91$23,595$6,419

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: 2 services

Original Medicare services billed in 2023
Short return visit (20+ min)11$890$74
Cervical or vaginal cancer screening; pelvic and clinical breast examination12$587$49

2022: 1 service

Original Medicare services billed in 2022
Cervical or vaginal cancer screening; pelvic and clinical breast examination14$676$48

2021: 3 services

Original Medicare services billed in 2021
Short return visit (20+ min)14$1,237$77
Cervical or vaginal cancer screening; pelvic and clinical breast examination16$784$49
Short return visit12$736$53

2020: 1 service

Original Medicare services billed in 2020
Cervical or vaginal cancer screening; pelvic and clinical breast examination11$539$49

2019: 4 services

Original Medicare services billed in 2019
New patient visit (15+ min)14$881$63
Cervical or vaginal cancer screening; pelvic and clinical breast examination18$854$47
Short return visit (20+ min)14$820$59
Short return visit11$627$39

2018: 1 service

Original Medicare services billed in 2018
Cervical or vaginal cancer screening; pelvic and clinical breast examination22$1,003$46

2017: 1 service

Original Medicare services billed in 2017
Short return visit (20+ min)20$1,592$69

2016: 1 service

Original Medicare services billed in 2016
Cervical or vaginal cancer screening; pelvic and clinical breast examination14$634$45

2015: 3 services

Original Medicare services billed in 2015
Short return visit (20+ min)27$2,051$57
Cervical or vaginal cancer screening; pelvic and clinical breast examination22$1,047$48
Short return visit14$617$39

2014: 1 service

Original Medicare services billed in 2014
Cervical or vaginal cancer screening; pelvic and clinical breast examination18$809$45

Drugs they prescribed that Part D paid

$9,367

Pharmacies billed $9,367 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 79) in 2024. At or below the middle of the specialty; the typical obstetrics & gynecology clinician is at 0%.

58 generic and 21 brand-name prescriptions · $9,367 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
Estradiol12$1,026$49

Year by year

Part D prescribing by year
202479300% (0)27%$9,367
20237023None24%$11,794
202259200% (0)25%$8,883
202151180% (0)39%$10,806
20206221None35%$12,925
201971240% (0)30%$11,166
201891290% (0)36%$16,625
2017112290% (0)50%$18,200
201614131None50%$16,561
201512635None55%$17,888
2014102260% (0)73%$12,984
20138226None50%$9,435

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

See the drugs prescribed each year

2023: 1 drug

Part D drugs prescribed in 2023
Estradiol20$1,725$86

2022: 1 drug

Part D drugs prescribed in 2022
Estradiol12$1,154$96

2020: 1 drug

Part D drugs prescribed in 2020
Estradiol17$2,979$175

2019: 1 drug

Part D drugs prescribed in 2019
Estradiol24$4,988$208

2018: 2 drugs

Part D drugs prescribed in 2018
Estradiol28$5,707$204
Premarin11$5,205$473

2017: 4 drugs

Part D drugs prescribed in 2017
Estrace17$4,875$287
Vagifem18$4,144$230
Estradiol14$2,030$145
Oxybutynin Chloride14$356$25

2016: 3 drugs

Part D drugs prescribed in 2016
Vagifem27$5,768$214
Premarin14$4,508$322
Estradiol36$2,007$56

2015: 4 drugs

Part D drugs prescribed in 2015
Premarin25$7,823$313
Estrace12$2,747$229
Vagifem16$2,626$164
Estradiol17$1,307$77

2014: 5 drugs

Part D drugs prescribed in 2014
Premarin17$4,149$244
Vagifem22$2,921$133
Estrace12$1,887$157
Vivelle-Dot14$1,664$119
Estradiol13$653$50

2013: 3 drugs

Part D drugs prescribed in 2013
Estrace18$2,506$139
Vivelle-Dot11$1,608$146
Vagifem15$1,158$77

Professional record

NPI
1003904350
Licence
CA G80084California G80084: Current · expires 2028-09-30
Trained
University of California, San Francisco School of Medicine, 1993
Video visits
Lists video visits
Gender
Female
More record details
Sole proprietor
No
Taxonomy
Federal specialty code 207V00000X (207V00000X)
Mailing address
325 Distel Cir, Los Altos, CA, 94022
NPI first listed
2006-10-11
NPI last updated
2020-03-04
NPI record certified
2020-03-04

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