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William K Marek

Clinical Psychologist · Mill Valley

NPI 1851560544

Medicare standing
Clear
Enrolled, allowed to bill and order, not excluded
Plans that list them
4
1 carrier
Offices
2

Offices

2 locations · Sud Specialty Group - CA · 519 clinicians in this group

Looking this up.

Plans that list them

4 plans · 1 carrier

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

Plans whose provider directory lists this clinician
Kaiser Permanente Dual Complete North P2 (HMO D-SNP)Kaiser PermanenteListedSep 1, 2026
Kaiser Permanente Dual Complete North P23 (HMO D-SNP)Kaiser PermanenteListedSep 1, 2026
Kaiser Permanente Sr Adv Basic Santa Clara (HMO)Kaiser PermanenteListedSep 1, 2026
Kaiser Permanente Sr Adv Enhanced Santa Clara (HMO)Kaiser PermanenteListedSep 1, 2026

Original Medicare doctor bills

$148,339

Medicare paid this office $148,339 for 176 people.

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

Largest Original Medicare bills
Psychotherapy, 30 minutes157$115,720$66
Evaluation of psychological test, first hour88$16,550$89
Psychiatric diagnostic evaluation104$15,473$145

Who their Medicare patients are

176 Original Medicare patients in 2024. Average age 79 · Women 55% · Also on Medicaid 79% · Health risk score 2.23. Above the middle of the specialty; the typical psychologist, clinical clinician is at 1.25.

Conditions among them: High blood pressure 75% · Depression 75% · Dementia 56% · Chronic kidney disease 48% · Heart failure 41% · Diabetes 38% · Coronary heart disease 37% · COPD 35% · Atrial fibrillation 32% · Stroke 19% · Cancer 15%.

The office billed $288,755, Medicare allowed $187,280 and paid $148,339; for 2,049 services of 5 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
20241762,049792.23$288,755$148,339
20231741,912782.07$269,105$129,889
20221511,932772.21$272,815$132,570
20211282,094762.45$293,780$150,962
2020941,101763.82$151,495$68,103
20191422,682753.60$352,685$161,250
2018801,901763.11$249,200$103,552
2017932,226743.28$291,300$120,322
2016932,146773.35$281,035$110,641
2015672,040793.44$266,065$103,680
2014922,079783.06$272,210$112,758
2013722,137783.14$279,105$72,548

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
Psychotherapy, 30 minutes151$100,494$62
Evaluation of psychological test, first hour95$15,060$88
Psychiatric diagnostic evaluation88$11,810$134

2022: 3 services

Original Medicare services billed in 2022
Psychotherapy, 30 minutes118$112,700$64
Psychiatric diagnostic evaluation80$10,702$132
Evaluation of psychological test, first hour50$9,082$90

2021: 3 services

Original Medicare services billed in 2021
Psychotherapy, 30 minutes116$117,463$66
Evaluation of psychological test, first hour84$18,767$92
Psychiatric diagnostic evaluation94$14,435$152

2020: 3 services

Original Medicare services billed in 2020
Psychotherapy, 30 minutes91$58,463$58
Evaluation of psychological test, first hour28$5,555$91
Psychiatric diagnostic evaluation32$3,960$116

2019: 3 services

Original Medicare services billed in 2019
Psychotherapy, 30 minutes129$130,884$55
Evaluation of psychological test, first hour83$18,663$90
Psychiatric diagnostic evaluation93$10,861$116

2018: 3 services

Original Medicare services billed in 2018
Psychotherapy, 30 minutes77$90,043$52
Psychological testing with interpretation and report by psychologist or physician per hour42$6,922$67
Psychiatric diagnostic evaluation43$4,636$105

2017: 3 services

Original Medicare services billed in 2017
Psychotherapy, 30 minutes91$105,677$52
Psychological testing with interpretation and report by psychologist or physician per hour53$8,478$65
Psychiatric diagnostic evaluation53$5,563$105

2016: 6 services

Original Medicare services billed in 2016
Psychotherapy, 30 minutes83$78,915$49
Psychotherapy, 30 minutes59$17,421$51
Psychological testing with interpretation and report by psychologist or physician per hour46$7,184$65
Psychiatric diagnostic evaluation44$4,542$101
Psychiatric diagnostic evaluation11$1,158$105
Psychological testing with interpretation and report by psychologist or physician per hour12$1,153$64

2015: 3 services

Original Medicare services billed in 2015
Psychotherapy, 30 minutes67$96,336$50
Psychological testing with interpretation and report by psychologist or physician per hour30$4,599$63
Psychiatric diagnostic evaluation27$2,745$98

2014: 3 services

Original Medicare services billed in 2014
Psychotherapy, 30 minutes89$99,952$52
Psychological testing with interpretation and report by psychologist or physician per hour43$7,237$66
Psychiatric diagnostic evaluation51$5,375$105

2013: 3 services

Original Medicare services billed in 2013
Psychotherapy, 30 minutes70$64,840$32
Psychological testing with interpretation and report by psychologist or physician per hour30$4,256$60
Psychiatric diagnostic evaluation32$3,001$94

Professional record

NPI
1851560544
Licence
CA PSY 14791
Video visits
Lists video visits
Gender
Male
More record details
Sole proprietor
Yes
Taxonomy
Federal specialty code 103T00000X (103T00000X)
Mailing address
105 Reflections Dr, Apt. 18, San Ramon, CA, 94583
NPI first listed
2008-02-27
NPI last updated
2008-02-27

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