NPI registry status
Active
2026 NPPES data Psychiatry Physician NPI 1205854999 M.D.
Verify on CMS → William Baker, M.D.
Psychiatry Physician in Milwaukee, Wisconsin.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 53,171 in Psychiatry Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
1K
Medicare Part D claims · 37 beneficiaries · Psychiatry Physician avg: 1K
Generic prescribing
88%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
William Baker, M.D. filed 1,234 Medicare Part D claims in 2023 as a Psychiatry Physician in Milwaukee, Wisconsin, prescribing 88% generic.
- 1K
- Part D claims, 2023
- 88%
- generic prescribing
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
William Baker, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,234 Top 22% higher than 78% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
William Baker, M.D. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about William Baker, M.D.?
Quality data not reportedPrimary specialty
Psychiatry Physician
Medicare Part D claims
1,234 19% vs specialty avg
Specialty distribution in Wisconsin
How Psychiatry Physician compares to other specialties among Wisconsin providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Psychiatry Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
William Baker, M.D. appears in the CMS NPPES registry as a Psychiatry Physician provider holding M.D. credentials at 1040 S. 70TH ST., Milwaukee, WI, 53214, with a listed phone of (414) 476-9675. NPI 1205854999 was issued on 07/18/2006.
Medicare Part D records for calendar year 2023 show 1,234 prescription claims written by this provider, covering 37 Medicare beneficiaries and totaling roughly $464K in drug spend, split 12% brand-name and 88% generic by claim count.
Psychiatry Physician is a high-volume specialty nationwide, with 53,171 enrolled providers across 56 states and an average of 1,038 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1205854999 |
|---|---|
| Specialty | Psychiatry Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 07/18/2006 |
Brand vs generic prescribing mix · Typical
William Baker, M.D. - brand share 12.0%
Psychiatry Physician average
12% brand-name claims vs 88% generic, on 1,234 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,234
Total Claims
$464K
Total Drug Cost
37
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,354
- Total Day Supply
- 37,832
- Brand vs Generic
- 12% brand / 88% generic
- Brand Drug Cost
- $408K
- Generic Drug Cost
- $57K
Patient Demographics
- Average Patient Age
- 56.5 years
- Avg HCC Risk Score
- 1.18
- Gender Split
- 49% female / 51% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What William Baker, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Aripiprazole
Aripiprazole
116 claims
- Clozapine
Clozapine
85 claims
- Escitalopram Oxalate
Escitalopram Oxalate
83 claims
- Invega Sustenna
Invega Sustenna
81 claims
- Trazodone Hcl
Trazodone Hcl
76 claims
- Clonazepam
Clonazepam
72 claims
- Quetiapine Fumarate
Quetiapine Fumarate
64 claims
- Venlafaxine Hcl Er
Venlafaxine Hcl Er
49 claims
| Drug | Claims |
|---|---|
| Aripiprazole | 116 |
| Clozapine | 85 |
| Escitalopram Oxalate | 83 |
| Invega Sustenna Paliperidone Palmitate | 81 |
| Trazodone Hcl | 76 |
| Clonazepam | 72 |
| Quetiapine Fumarate | 64 |
| Venlafaxine Hcl Er Venlafaxine Hcl | 49 |
| Divalproex Sodium Er Divalproex Sodium | 43 |
| Bupropion Xl Bupropion Hcl | 39 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Psychiatry Physician Overview
How William Baker, M.D. fits within the Psychiatry Physician landscape nationally.
53,171
Psychiatry Physician Providers in US
56
States with Psychiatry Physician
1,038
Avg Claims per Provider
William Baker, M.D.'s 1,234 claims are above the specialty average of 1,038.
Nearby Psychiatry Physician Providers in Wisconsin
Other clinicians with the same primary specialty enrolled in Wisconsin, drawn from the same CMS NPPES roster as Baker.
Dr. Semhal Abbay
MD
Green Bay, WI
Dr. Beth Abramson
M.D.
Milwaukee, WI
Dr. Sean Ackerman
M.D.
Columbus, WI
Dr. Nagwa Agaiby
M.D.
Milwaukee, WI
Dr. Himanshu Agrawal
M.D.
Milwaukee, WI
Compare Psychiatry Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Wisconsin medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Psychiatry Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is William Baker, M.D.'s specialty? ▼
William Baker, M.D. specializes in Psychiatry Physician and practices in Milwaukee, Wisconsin. Credentials: M.D..
How much does William Baker, M.D. prescribe under Medicare Part D? ▼
In 2023, William Baker, M.D. wrote 1,234 Medicare Part D claims totaling $464K in drug costs for 37 beneficiaries.
Where is William Baker, M.D. located? ▼
William Baker, M.D. is located at 1040 S. 70TH ST., Milwaukee, WI, 53214. Phone: (414) 476-9675.
What is William Baker, M.D.'s NPI number? ▼
William Baker, M.D.'s National Provider Identifier (NPI) is 1205854999, issued on 07/18/2006.
Does William Baker, M.D. prescribe more brand-name or generic drugs? ▼
William Baker, M.D.'s prescribing is 12% brand-name and 88% generic drugs by claim count, with $408K in brand drug costs.
How many Psychiatry Physician providers are there in the US? ▼
There are 53,171 Psychiatry Physician providers across 56 states in the US. The average Psychiatry Physician provider writes 1,038 Medicare Part D claims per year.
What drugs does William Baker, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, William Baker, M.D.'s most frequently prescribed drugs include Aripiprazole, Clozapine, Escitalopram Oxalate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Baker, M.D. accept Medicare? ▼
William Baker, M.D. appears in CMS Medicare data with 1,234 Part D claims and 37 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Baker, M.D.'s credentials? ▼
William Baker, M.D.'s NPI is 1205854999 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.