2026 NPPES data Anatomic Pathology Physician NPI 1447699582 MD
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KRISTEN VIERREGGER, MD

Anatomic Pathology Physician in BUENA PARK, California. 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
224
Medicare Part D claims · 31 beneficiaries · Anatomic Pathology Physician avg: 214
Generic prescribing
92%
generic claims · 8% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

KRISTEN VIERREGGER, MD filed 224 Medicare Part D claims in 2023 as a Anatomic Pathology Physician in BUENA PARK, California, prescribing 92% generic.

224
Part D claims, 2023
92%
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.

KRISTEN VIERREGGER, MD's Medicare Part D volume vs every U.S. prescriber

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

224 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. 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-eligible specialty (heuristic — not verified)

KRISTEN VIERREGGER, MD 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 KRISTEN VIERREGGER, MD?

Quality data not reported

NPI registry status

Active

Issued 06/21/2013

NPI 1447699582

Primary specialty

Anatomic Pathology Physician

Niche

2,597 US NPIs in this specialty

Medicare Part D claims

224 5% vs specialty avg

2023 prescription claims

Specialty avg: 214

Specialty distribution in California

How Anatomic Pathology Physician compares to other specialties among California providers

California providers

Anatomic Pathology Physician share within California

1. Anatomic Pathology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Anatomic Pathology Physician share within California

Specialty board-certification context

Estimated specialty board-certified rate — Anatomic Pathology Physician (ABMS / AOA reference)

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

Est. board-certified rate (Anatomic Pathology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Anatomic Pathology 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).

KRISTEN VIERREGGER, MD appears in the CMS NPPES registry as a Anatomic Pathology Physician provider holding MD credentials at 8081 STANTON AVE STE 300, BUENA PARK, CA, 90620, with a listed phone of (714) 484-8000. NPI 1447699582 was issued on 06/21/2013. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what VIERREGGER 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 224 prescription claims written by this provider, covering 31 Medicare beneficiaries and totaling roughly $19K in drug spend, split 8% brand-name and 92% generic by claim count. 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.

Anatomic Pathology Physician is a narrow specialty nationwide, with 2,597 enrolled providers across 54 states and an average of 214 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

8081 STANTON AVE STE 300
BUENA PARK, CA 90620

Provider Details

NPI 1447699582
Specialty Anatomic Pathology Physician
Credentials MD
Gender Female
NPI Issued 06/21/2013

License & disciplinary context — California MBC 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 ~150K California medical licensees in 2023 — they are NOT specific to KRISTEN VIERREGGER, MD. To verify KRISTEN VIERREGGER, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC 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 California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Generic-heavy

KRISTEN VIERREGGER, MD — brand share 8.0%
Specialty average (est.)

8% brand-name claims vs 92% generic, on 224 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.

224
Total Claims
$19K
Total Drug Cost
31
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
440
Total Day Supply
13,011
Brand vs Generic
8% brand / 92% generic
Brand Drug Cost
$5K
Generic Drug Cost
$14K

Patient Demographics

Average Patient Age
65.1 years
Avg HCC Risk Score
0.77
Gender Split
39% female / 61% male

Top Prescribed Drugs (Medicare Part D)

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

What KRISTEN VIERREGGER, 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
Estradiol Valerate
33
Estradiol
20
Bicalutamide
18
Estradiol (Twice Weekly)
Estradiol
16
Levothyroxine Sodium
14
Hydrochlorothiazide
12
Losartan Potassium
12
Progesterone
"Progesterone
N/A

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

Anatomic Pathology Physician Overview

How KRISTEN VIERREGGER, MD fits within the Anatomic Pathology Physician landscape nationally.

2,597
Anatomic Pathology Physician Providers in US
54
States with Anatomic Pathology Physician
214
Avg Claims per Provider

KRISTEN VIERREGGER, MD's 224 claims are above the specialty average of 214.

Nearby Anatomic Pathology Physician Providers in California

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

Compare Anatomic Pathology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is KRISTEN VIERREGGER, MD's specialty?
KRISTEN VIERREGGER, MD specializes in Anatomic Pathology Physician and practices in BUENA PARK, California. Credentials: MD.
How much does KRISTEN VIERREGGER, MD prescribe under Medicare Part D?
In 2023, KRISTEN VIERREGGER, MD wrote 224 Medicare Part D claims totaling $19K in drug costs for 31 beneficiaries.
Where is KRISTEN VIERREGGER, MD located?
KRISTEN VIERREGGER, MD is located at 8081 STANTON AVE STE 300, BUENA PARK, CA, 90620. Phone: (714) 484-8000.
What is KRISTEN VIERREGGER, MD's NPI number?
KRISTEN VIERREGGER, MD's National Provider Identifier (NPI) is 1447699582, issued on 06/21/2013.
Does KRISTEN VIERREGGER, MD prescribe more brand-name or generic drugs?
KRISTEN VIERREGGER, MD's prescribing is 8% brand-name and 92% generic drugs by claim count, with $5K in brand drug costs.
How many Anatomic Pathology Physician providers are there in the US?
There are 2,597 Anatomic Pathology Physician providers across 54 states in the US. The average Anatomic Pathology Physician provider writes 214 Medicare Part D claims per year.
What drugs does KRISTEN VIERREGGER, MD prescribe most often?
Based on 2023 Medicare Part D data, KRISTEN VIERREGGER, MD's most frequently prescribed drugs include Estradiol Valerate, Estradiol, Bicalutamide. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does KRISTEN VIERREGGER, MD accept Medicare?
KRISTEN VIERREGGER, MD appears in CMS Medicare data with 224 Part D claims and 31 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify KRISTEN VIERREGGER, MD's credentials?
KRISTEN VIERREGGER, MD's NPI is 1447699582 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