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Karen Butterfield, MD

Internal Medicine · Palo Alto

NPI 1619083144

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

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. Butterfield’s office at (650) 321-4121 to ask if they take your plan before you enroll.

California Medical Board record

Licence G69715 · Current

Licensed to practise in California · since 1990 · expires 2028-03-31 · Stanford University School of Medicine.

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

School, training and certification

What this clinician told their state board, medical school and everything before it. Only some states publish this, so nothing here means the state does not say, not that there was no training or certification.

Specialty certification

  • American Board of Internal Medicine - Internal Medicine

Original Medicare doctor bills

$10,979

Medicare paid this office $10,979 for 70 people. Most of that is long return visits and Botox.

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

Largest Original Medicare bills
Long return visit (40+ min)43$6,881$156
Return visit (30+ min)18$1,450$81

Who their Medicare patients are

70 Original Medicare patients in 2024. Average age 78 · Women 73% · Health risk score 0.97. At or below the middle of the specialty; the typical internal medicine clinician is at 1.76.

Conditions among them: High blood pressure 66% · Coronary heart disease 23% · Cancer 20% · Depression 20% · Atrial fibrillation 16%.

The office billed $35,554, Medicare allowed $15,415 and paid $10,979; for 93 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
20247093780.97$35,554$10,979
202385115790.85$38,314$13,844
20224163770.74$17,511$7,781
20212128780.64$7,535$3,288
20203754760.94$11,836$4,452
20191315701.18$3,635$1,009
2018259910750.75$214,235$81,228
2017258824760.80$187,948$74,050
2016267881750.84$190,459$76,384
20152621,053750.83$185,555$89,914
2014268801740.82$146,294$61,210
2013246576740.86$111,395$45,384

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: 3 services

Original Medicare services billed in 2023
Long return visit (40+ min)33$5,349$162
Return visit (30+ min)37$4,477$115
Short return visit (20+ min)13$1,036$80

2022: 2 services

Original Medicare services billed in 2022
Return visit (30+ min)32$4,154$130
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit12$1,869$156

2021: 1 service

Original Medicare services billed in 2021
Return visit (30+ min)12$1,513$126

2020: 1 service

Original Medicare services billed in 2020
Return visit (30+ min)11$831$76

2018: 12 services

Original Medicare services billed in 2018
Return visit (30+ min)197$23,540$86
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit158$20,749$131
Long return visit (40+ min)81$17,165$122
Short return visit (20+ min)60$3,954$56
Pneumococcal vaccine, 13-valent13$2,576$198
Pneumococcal vaccine, 23-valent22$2,323$106
Influenza vaccine split virus, preservative free45$1,987$43
Advance care planning, first 30 minutes17$1,617$85
Administration of influenza virus vaccine47$1,235$26
Administration of pneumococcal vaccine35$901$26
Short return visit11$298$27
Removal of impacted ear wax by washing14$195$14

2017: 9 services

Original Medicare services billed in 2017
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit156$19,874$127
Return visit (30+ min)182$19,647$85
Long return visit (40+ min)89$16,012$126
Short return visit (20+ min)56$3,354$54
Pneumococcal vaccine, 23-valent22$2,070$94
Influenza vaccine split virus, preservative free44$1,892$43
Advance care planning, first 30 minutes17$1,540$86
Administration of influenza virus vaccine44$1,405$32
Administration of pneumococcal vaccine30$911$30

2016: 11 services

Original Medicare services billed in 2016
Return visit (30+ min)196$23,855$85
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit152$19,152$126
Long return visit (40+ min)46$9,113$127
Pneumococcal vaccine, 13-valent35$6,117$175
Short return visit (20+ min)84$5,788$58
Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit14$2,579$184
Influenza vaccine split virus, preservative free47$1,735$36
Administration of influenza virus vaccine54$1,671$30
Administration of pneumococcal vaccine48$1,458$30
Pneumococcal vaccine, 23-valent13$1,139$88
Short return visit11$333$30

2015: 10 services

Original Medicare services billed in 2015
Pneumococcal vaccine, 13-valent169$25,616$152
Return visit (30+ min)152$19,108$91
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit136$17,881$131
Short return visit (20+ min)123$6,963$46
Long return visit (40+ min)37$6,186$132
Administration of pneumococcal vaccine171$5,195$30
Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit16$3,092$193
Influenza vaccine split virus, preservative free39$1,374$35
Administration of influenza virus vaccine42$1,346$31
Short return visit24$795$33

2014: 11 services

Original Medicare services billed in 2014
Short return visit (20+ min)185$13,765$52
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit92$11,540$125
Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit60$11,054$184
Return visit (30+ min)84$10,820$88
Long return visit (40+ min)35$4,965$121
Administration of influenza virus vaccine53$1,610$30
Influenza vaccine split virus, preservative free42$1,373$33
Short return visit37$1,370$35
Pneumococcal vaccine, 23-valent17$1,083$64
Administration of pneumococcal vaccine24$729$30
Influenza vaccine, quadrivalent, preservative free, 0.5 ml dosage12$218$18

2013: 9 services

Original Medicare services billed in 2013
Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit75$13,889$185
Short return visit (20+ min)155$10,710$56
Return visit (30+ min)89$9,227$80
Long return visit (40+ min)23$3,073$114
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit21$2,642$126
Short return visit33$1,265$37
Administration of influenza virus vaccine21$639$30
Administration of vaccine24$457$19
Influenza vaccine, quadrivalent, preservative free, 0.5 ml dosage20$372$19

Drugs they prescribed that Part D paid

$1,777

Pharmacies billed $1,777 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 98) in 2024. At or below the middle of the specialty; the typical internal medicine clinician is at 1%.

94 generic and fewer than 11 brand-name prescriptions · $1,777 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
Losartan13$212$16
Amlodipine Besylate11$29$3

Year by year

Part D prescribing by year
202498310% (0)None$1,777
2023150440% (0)None$3,754
20228932NoneNone$2,990
202180270% (0)24%$2,282
2020241620% (0)None$12,882
20191,007180NoneNone$54,448
20182,7122441% (23)None$119,087
20172,7882452% (43)None$124,570
20162,7012472% (54)None$140,375
20152,6342342% (64)None$117,343
20142,5312283% (69)18%$125,319
20132,9332473% (87)None$167,136

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
Losartan18$205$11
Atorvastatin12$184$15

2022: 1 drug

Part D drugs prescribed in 2022
Atorvastatin11$121$11

2021: 2 drugs

Part D drugs prescribed in 2021
Atorvastatin15$727$48
Levothyroxine14$422$30

2020: 5 drugs

Part D drugs prescribed in 2020
Levothyroxine22$601$27
Atorvastatin27$461$17
Tamsulosin13$249$19
Simvastatin22$202$9
Amlodipine Besylate18$193$11

2019: 20 drugs

Part D drugs prescribed in 2019
Eliquis17$8,145$479
Levothyroxine115$3,046$26
Atorvastatin107$2,226$21
Synthroid18$1,521$85
Omeprazole39$1,168$30
Losartan39$864$22
Amlodipine Besylate68$753$11
Simvastatin77$743$10
Lisinopril49$618$13
Metoprolol25$553$22
Valsartan14$494$35
Metformin14$252$18
Furosemide17$251$15
Potassium Chloride17$241$14
Citalopram Hbr11$208$19
Atenolol15$208$14
Hydrochlorothiazide28$200$7
Benazepril15$183$12
Triamterene-Hydrochlorothiazid14$139$10
Sertraline11$102$9

2018: 52 drugs

Part D drugs prescribed in 2018
Eliquis15$6,431$429
Levothyroxine192$5,138$27
Atorvastatin224$4,322$19
Colchicine12$3,892$324
Omeprazole115$2,275$20
Synthroid30$2,145$71
Metoprolol68$2,118$31
Simvastatin166$1,667$10
Benazepril-Hydrochlorothiazide22$1,578$72
Ipratropium15$1,538$103
Valsartan27$1,444$53
Amlodipine Besylate178$1,329$7
Losartan78$1,099$14
Lisinopril114$1,058$9
Oxybutynin Chloride Er17$1,053$62
Gabapentin40$972$24
Potassium Chloride60$957$16
Bupropion Hcl Sr12$670$56
Polyethylene Glycol 335017$656$39
Pravastatin22$588$27
Paroxetine20$540$27
Triamterene-Hydrochlorothiazid32$505$16
Hydrochlorothiazide65$460$7
Warfarin29$439$15
Nitrofurantoin Mono-Macro22$434$20
Metformin40$433$11
Alprazolam46$429$9
Benazepril37$386$10
Zolpidem58$354$6
Furosemide37$336$9
Valacyclovir12$333$28
Ranitidine22$315$14
Pantoprazole17$297$17
Fluoxetine15$295$20
Atenolol43$284$7
Citalopram Hbr26$276$11
Alendronate30$270$9
Sertraline31$261$8
Lovastatin21$250$12
Fluticasone Propionate12$230$19
Trazodone15$229$15
Felodipine Er13$203$16
Metformin Hcl Er18$172$10
Isosorbide Mononitrate Er12$156$13
Azithromycin27$145$5
Lisinopril-Hydrochlorothiazide22$127$6
Clopidogrel11$125$11
Acyclovir11$120$11
Clonazepam25$115$5
Metoprolol20$86$4
Lorazepam22$81$4
Acetaminophen-Codeine12$76$6

2017: 64 drugs

Part D drugs prescribed in 2017
Advair Diskus18$9,220$512
Levothyroxine191$5,738$30
Tretinoin Microsphere13$4,949$381
Atorvastatin227$4,751$21
Eliquis12$4,737$395
Flovent Hfa14$4,099$293
Colchicine14$4,068$291
Desonide13$3,337$257
Proair Hfa41$2,784$68
Omeprazole116$2,263$20
Synthroid36$2,231$62
Butalbital-Acetaminophen-Caffe13$2,197$169
Metoprolol51$1,664$33
Valsartan19$1,590$84
Amlodipine Besylate150$1,387$9
Simvastatin143$1,336$9
Benazepril-Hydrochlorothiazide19$1,079$57
Gabapentin37$1,024$28
Losartan83$900$11
Lisinopril116$872$8
Potassium Chloride40$764$19
Valsartan-Hydrochlorothiazide14$690$49
Klor-Con 1014$610$44
Warfarin35$603$17
Fluticasone Propionate34$562$17
Hydrochlorothiazide68$531$8
Allopurinol18$514$29
Triamterene-Hydrochlorothiazid33$513$16
Tamsulosin13$452$35
Spironolactone-Hctz12$445$37
Pravastatin19$444$23
Metformin38$444$12
Nitrofurantoin Mono-Macro21$440$21
Polyethylene Glycol 335022$437$20
Nitrostat15$422$28
Alprazolam39$381$10
Paroxetine20$379$19
Pantoprazole17$354$21
Alendronate37$336$9
Benazepril30$310$10
Zolpidem54$293$5
Lisinopril-Hydrochlorothiazide29$288$10
Atenolol44$283$6
Carvedilol21$282$13
Valacyclovir15$274$18
Sertraline30$266$9
Lovastatin27$256$9
Furosemide39$253$6
Hydrocodone-Acetaminophen22$249$11
Fluoxetine29$248$9
Citalopram Hbr36$244$7
Trazodone13$229$18
Lorazepam37$222$6
Metoprolol20$197$10
Isosorbide Mononitrate Er12$180$15
Azithromycin26$158$6
Cartia Xt11$157$14
Acyclovir12$141$12
Felodipine Er11$125$11
Ranitidine15$112$7
Metformin Hcl Er11$110$10
Acetaminophen-Codeine16$100$6
Ciprofloxacin13$77$6
Clopidogrel12$69$6

2016: 59 drugs

Part D drugs prescribed in 2016
Advair Diskus17$8,261$486
Levothyroxine165$5,164$31
Flovent Hfa11$4,163$378
Atorvastatin187$4,095$22
Colchicine12$3,565$297
Estrace13$3,404$262
Proair Hfa44$2,919$66
Synthroid37$2,606$70
Omeprazole121$2,246$19
Simvastatin171$2,160$13
Valsartan18$1,931$107
Benazepril-Hydrochlorothiazide21$1,670$80
Metoprolol37$1,546$42
Amlodipine Besylate140$1,339$10
Losartan81$965$12
Gabapentin35$945$27
Lisinopril118$879$7
Zolpidem62$851$14
Pravastatin20$807$40
Warfarin38$715$19
Hydrocodone-Acetaminophen25$667$27
Hydrochlorothiazide77$629$8
Nitrostat18$564$31
Tamsulosin15$555$37
Klor-Con 1013$522$40
Nitrofurantoin Mono-Macro24$478$20
Metformin43$467$11
Allopurinol21$422$20
Paroxetine22$386$18
Alprazolam43$378$9
Triamterene-Hydrochlorothiazid21$358$17
Alendronate27$358$13
Sertraline28$339$12
Potassium Chloride20$339$17
Trazodone16$334$21
Furosemide41$333$8
Fluticasone Propionate25$329$13
Lovastatin22$308$14
Pantoprazole17$287$17
Citalopram Hbr35$283$8
Metoprolol24$283$12
Atenolol41$271$7
Montelukast12$258$22
Carvedilol15$256$17
Benazepril27$249$9
Isosorbide Mononitrate Er17$231$14
Felodipine Er13$227$17
Lorazepam26$221$8
Lisinopril-Hydrochlorothiazide26$218$8
Fluoxetine18$216$12
Acyclovir14$198$14
Clopidogrel18$190$11
Azithromycin23$174$8
Venlafaxine Hcl Er11$169$15
Amoxicillin21$165$8
Acetaminophen-Codeine17$159$9
Ranitidine18$140$8
Butalbital-Acetaminophen-Caffe12$69$6
Clonazepam12$67$6

2015: 59 drugs

Part D drugs prescribed in 2015
Levothyroxine161$5,060$31
Advair Diskus13$4,695$361
Estrace17$3,827$225
Atorvastatin153$3,667$24
Flovent Hfa13$2,684$206
Synthroid46$2,652$58
Valsartan16$2,568$160
Colcrys13$2,345$180
Omeprazole140$1,850$13
Benazepril-Hydrochlorothiazide21$1,836$87
Metoprolol36$1,712$48
Simvastatin151$1,353$9
Proair Hfa19$1,251$66
Rivastigmine11$1,082$98
Allopurinol27$1,010$37
Gabapentin31$943$30
Pravastatin22$929$42
Tamsulosin17$835$49
Amlodipine Besylate99$817$8
Potassium Chloride28$797$28
Lisinopril99$771$8
Ventolin Hfa16$770$48
Hydrochlorothiazide77$725$9
Hydrocodone-Acetaminophen37$706$19
Losartan87$701$8
Zolpidem42$682$16
Montelukast17$513$30
Fluticasone Propionate38$507$13
Warfarin21$411$20
Metformin45$397$9
Ipratropium12$368$31
Furosemide48$365$8
Lorazepam28$363$13
Pantoprazole16$351$22
Atenolol39$348$9
Isosorbide Mononitrate Er14$345$25
Triamterene-Hydrochlorothiazid24$309$13
Sertraline29$295$10
Lisinopril-Hydrochlorothiazide31$288$9
Lovastatin28$286$10
Felodipine Er14$284$20
Citalopram Hbr30$280$9
Metoprolol25$279$11
Fluoxetine19$271$14
Acetaminophen-Codeine19$267$14
Paroxetine20$257$13
Sumatriptan14$238$17
Trazodone19$227$12
Alprazolam33$215$7
Benazepril29$209$7
Alendronate24$182$8
Azithromycin27$174$6
Donepezil20$167$8
Clopidogrel11$167$15
Ranitidine15$151$10
Amoxicillin17$139$8
Naproxen11$103$9
Ciprofloxacin14$72$5
Clonazepam14$62$4

2014: 61 drugs

Part D drugs prescribed in 2014
Advair Diskus26$9,505$366
Diovan16$6,491$406
Levothyroxine163$3,659$22
Flovent Hfa15$3,578$239
Synthroid56$3,478$62
Montelukast18$2,986$166
Atorvastatin126$2,974$24
Colcrys15$2,846$190
Estrace17$2,779$163
Simvastatin187$1,976$11
Omeprazole109$1,692$16
Metoprolol25$1,384$55
Benazepril-Hydrochlorothiazide19$1,275$67
Losartan73$1,143$16
Nifedipine Er14$1,057$76
Gabapentin44$1,047$24
Proair Hfa17$1,000$59
Amlodipine Besylate102$939$9
Fluticasone Propionate39$844$22
Lisinopril86$802$9
Pravastatin19$738$39
Hydrocodone-Acetaminophen37$726$20
Potassium Chloride23$615$27
Klor-Con 1020$568$28
Ventolin Hfa13$568$44
Ipratropium11$523$48
Lisinopril-Hydrochlorothiazide38$486$13
Tamsulosin15$462$31
Hydrochlorothiazide51$418$8
Atenolol43$416$10
Allopurinol23$388$17
Zolpidem44$341$8
Metformin31$330$11
Citalopram Hbr36$305$8
Lorazepam48$280$6
Clotrimazole13$279$21
Paroxetine21$277$13
Nitrofurantoin Mono-Macro13$269$21
Furosemide36$247$7
Triamterene-Hydrochlorothiazid17$237$14
Metoprolol18$236$13
Fluoxetine21$223$11
Clonazepam39$223$6
Sertraline21$215$10
Alprazolam24$212$9
Felodipine Er13$210$16
Azithromycin25$207$8
Nitrostat12$199$17
Trazodone15$195$13
Pantoprazole14$193$14
Warfarin11$191$17
Clopidogrel16$187$12
Acetaminophen-Codeine21$168$8
Donepezil16$167$10
Alendronate21$164$8
Naproxen12$145$12
Amoxicillin15$142$9
Ranitidine16$136$9
Benazepril13$112$9
Glipizide11$107$10
Ciprofloxacin13$77$6

2013: 64 drugs

Part D drugs prescribed in 2013
Diovan48$13,182$275
Advair Diskus39$12,507$321
Montelukast39$5,686$146
Atorvastatin119$4,717$40
Celebrex17$4,222$248
Spiriva13$3,564$274
Estrace22$3,141$143
Levothyroxine178$3,061$17
Synthroid52$2,780$53
Flovent Hfa12$2,567$214
Simvastatin181$2,360$13
Colcrys15$2,356$157
Metoprolol34$2,217$65
Omeprazole106$1,596$15
Proair Hfa26$1,534$59
Amlodipine Besylate124$1,251$10
Potassium Chloride55$1,204$22
Fluticasone Propionate41$1,135$28
Pravastatin42$1,091$26
Lisinopril131$1,080$8
Losartan61$1,079$18
Gabapentin44$914$21
Tamsulosin30$830$28
Zolpidem97$805$8
Hydrocodone-Acetaminophen59$798$14
Lisinopril-Hydrochlorothiazide46$691$15
Atenolol59$688$12
Doxycycline Hyclate15$678$45
Klor-Con 1016$660$41
Benazepril-Hydrochlorothiazide20$642$32
Hydrochlorothiazide87$544$6
Ventolin Hfa11$464$42
Metformin35$449$13
Polyethylene Glycol 335014$445$32
Bupropion Hcl Sr12$442$37
Clopidogrel21$395$19
Citalopram Hbr45$387$9
Donepezil19$379$20
Triamterene-Hctz21$378$18
Allopurinol22$375$17
Isosorbide Mononitrate Er19$373$20
Labetalol11$353$32
Levoxyl15$352$23
Amoxicillin18$346$19
Pantoprazole17$339$20
Lovastatin15$315$21
Metoprolol23$288$13
Triamcinolone Acetonide11$283$26
Ranitidine17$267$16
Nitrofurantoin Mono-Macro11$265$24
Lorazepam30$240$8
Furosemide42$233$6
Nitrostat17$213$13
Paroxetine16$208$13
Alprazolam32$201$6
Alendronate14$193$14
Sertraline16$189$12
Acetaminophen-Codeine19$168$9
Azithromycin15$149$10
Ciprofloxacin21$147$7
Glipizide11$100$9
Fluoxetine16$93$6
Trazodone19$93$5
Clonazepam12$55$5

Professional record

NPI
1619083144
Licence
CA G69715California G69715: Current · expires 2028-03-31
More record details
Sole proprietor
No
Taxonomy
Internal medicine (207R00000X)
Mailing address
2350 W. El Camino Real, 2nd Floor, Mountain View, CA, 94040
NPI first listed
2006-08-21
NPI last updated
2012-01-06

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