2026 NPPES data Internal Medicine Physician NPI 1811912892 MD
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PETER BOSAK, MD

Internal Medicine Physician in AUBURN, Washington. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
10K
Medicare Part D claims · 758 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
91%
generic claims · 9% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

PETER BOSAK, MD filed 9,968 Medicare Part D claims in 2023 as a Internal Medicine Physician in AUBURN, Washington, prescribing 91% generic.

10K
Part D claims, 2023
91%
generic prescribing
Likely
board-certified (heuristic)

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.

PETER BOSAK, MD's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

9,968 Top 2% higher than 98% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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 certification likely (heuristic — not verified)

PETER BOSAK, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 3 hospital affiliations — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about PETER BOSAK, MD?

Quality data not reported

NPI registry status

Active

Issued 07/12/2006

NPI 1811912892

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

9,968 267% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Washington

How Internal Medicine Physician compares to other specialties among Washington providers

Washington providers

Internal Medicine Physician share within Washington

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within Washington

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Internal Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

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).

PETER BOSAK, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 202 N DIVISION ST, AUBURN, WA, 98001, with a listed phone of (253) 876-7997. NPI 1811912892 was issued on 07/12/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what BOSAK most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 9,968 prescription claims written by this provider, covering 758 Medicare beneficiaries and totaling roughly $687K in drug spend, split 9% brand-name and 91% generic by claim count, with an opioid prescribing rate of 4.7%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

202 N DIVISION ST
AUBURN, WA 98001

Provider Details

NPI 1811912892
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 07/12/2006

Hospital and facility affiliations

Facilities where PETER BOSAK, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

MULTICARE HEALTH SYSTEM
AUBURN, WA
SELECT OUTPATIENT SERVICES INC
GLENVIEW, IL
SELECT REHABILITATION, LLC
GLENVIEW, IL

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — Washington WMC 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~34K Washington medical licensees in 2023 — they are NOT specific to PETER BOSAK, MD. To verify PETER BOSAK, MD's current license status, search the WMC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

88
Total board actions, Washington 2023
Across 85 cases
2.59
Actions per 1,000 licensees
Washington statewide rate
probation
Most common action type
31 cases

WMC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Washington disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Generic-heavy

PETER BOSAK, MD — brand share 9.0%
Specialty average (est.)

9% brand-name claims vs 91% generic, on 9,968 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.

9,968
Total Claims
$687K
Total Drug Cost
758
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
23,789
Total Day Supply
700,927
Brand vs Generic
9% brand / 91% generic
Brand Drug Cost
$505K
Generic Drug Cost
$177K
Opioid Claims
465 (4.7% rate)
Antibiotic Claims
101

Patient Demographics

Average Patient Age
75.7 years
Avg HCC Risk Score
1.28
Gender Split
44% female / 56% male
Age Distribution
<65: 54, 65-74: 282, 75-84: 290, 85+: 132

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What PETER BOSAK, MD prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
574
Lisinopril
518
Amlodipine Besylate
442
Losartan Potassium
300
Levothyroxine Sodium
298
Gabapentin
291
Metformin Hcl
286
Simvastatin
257
Tamsulosin Hcl
231
Metoprolol Succinate
229

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Internal Medicine Physician Overview

How PETER BOSAK, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

PETER BOSAK, MD's 9,968 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Washington

Other clinicians with the same primary specialty enrolled in Washington, drawn from the same CMS NPPES roster as BOSAK.

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is PETER BOSAK, MD's specialty?
PETER BOSAK, MD specializes in Internal Medicine Physician and practices in AUBURN, Washington. Credentials: MD.
How much does PETER BOSAK, MD prescribe under Medicare Part D?
In 2023, PETER BOSAK, MD wrote 9,968 Medicare Part D claims totaling $687K in drug costs for 758 beneficiaries.
Where is PETER BOSAK, MD located?
PETER BOSAK, MD is located at 202 N DIVISION ST, AUBURN, WA, 98001. Phone: (253) 876-7997.
What is PETER BOSAK, MD's NPI number?
PETER BOSAK, MD's National Provider Identifier (NPI) is 1811912892, issued on 07/12/2006.
Does PETER BOSAK, MD prescribe more brand-name or generic drugs?
PETER BOSAK, MD's prescribing is 9% brand-name and 91% generic drugs by claim count, with $505K in brand drug costs.
Does PETER BOSAK, MD prescribe opioids?
Yes, PETER BOSAK, MD had 465 opioid claims in 2023 with an opioid prescribing rate of 4.7%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does PETER BOSAK, MD prescribe most often?
Based on 2023 Medicare Part D data, PETER BOSAK, MD's most frequently prescribed drugs include Atorvastatin Calcium, Lisinopril, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does PETER BOSAK, MD accept Medicare?
PETER BOSAK, MD appears in CMS Medicare data with 9,968 Part D claims and 758 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify PETER BOSAK, MD's credentials?
PETER BOSAK, MD's NPI is 1811912892 with credentials MD. 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

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