NPI registry status
Active
2026 NPPES data Allergy & Immunology (Internal Medicine) Physician NPI 1376527804 M.D.
Verify on CMS → Rosemary Hallett, M.D.
Allergy & Immunology (Internal Medicine) Physician in Davis, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 520 in Allergy & Immunology (Internal Medicine) 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
906
Medicare Part D claims · 194 beneficiaries · Allergy & Immunology (Internal Medicine) Physician avg: 798
Generic prescribing
46%
generic claims · 54% 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
Rosemary Hallett, M.D. filed 906 Medicare Part D claims in 2023 as a Allergy & Immunology (Internal Medicine) Physician in Davis, California, prescribing 46% generic.
- 906
- Part D claims, 2023
- 46%
- 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.
Rosemary Hallett, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
906 Top 25% higher than 75% 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 certification likely (heuristic, not verified)
Rosemary Hallett, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - 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 Rosemary Hallett, M.D.?
Quality data not reportedPrimary specialty
Allergy & Immunology (Internal Medicine) Physician
Medicare Part D claims
906 14% vs specialty avg
Specialty distribution in California
How Allergy & Immunology (Internal Medicine) Physician compares to other specialties among California 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 Allergy & Immunology (Internal Medicine) 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).
Rosemary Hallett, M.D. appears in the CMS NPPES registry as a Allergy & Immunology (Internal Medicine) Physician provider holding M.D. credentials at 451 E. HEALTH SCIENCES DR, Davis, CA, 95616, with a listed phone of (530) 752-2884. NPI 1376527804 was issued on 11/29/2005.
Medicare Part D records for calendar year 2023 show 906 prescription claims written by this provider, covering 194 Medicare beneficiaries and totaling roughly $1.1 million in drug spend, split 54% brand-name and 46% generic by claim count.
Allergy & Immunology (Internal Medicine) Physician is a narrow specialty nationwide, with 520 enrolled providers across 48 states and an average of 798 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 | 1376527804 |
|---|---|
| Specialty | Allergy & Immunology (Internal Medicine) Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 11/29/2005 |
Hospital and facility affiliations
Facilities where Rosemary Hallett, M.D. 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.
Regents OF The University OF California
Roseville, CA
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 - 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 Rosemary Hallett, M.D.. To verify Rosemary Hallett, M.D.'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 · Brand-heavy
Rosemary Hallett, M.D. - brand share 54.0%
Allergy & Immunology (Internal Medicine) Physician average
54% brand-name claims vs 46% generic, on 906 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.
906
Total Claims
$1.1M
Total Drug Cost
194
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,453
- Total Day Supply
- 41,741
- Brand vs Generic
- 54% brand / 46% generic
- Brand Drug Cost
- $1.1M
- Generic Drug Cost
- $44K
Patient Demographics
- Average Patient Age
- 70.7 years
- Avg HCC Risk Score
- 1.02
- Gender Split
- 69% female / 31% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Rosemary Hallett, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Symbicort
Symbicort
190 claims
- Azelastine Hcl
Azelastine Hcl
128 claims
- Ipratropium Bromide 59
Ipratropium Bromide
59 claims
- Spiriva Respimat 57
Spiriva Respimat
57 claims
- Omeprazole 55
Omeprazole
55 claims
- Fluticasone Propio… 51
Fluticasone Propionate
51 claims
- Dupixent Pen 40
Dupixent Pen
40 claims
- Montelukast Sodium 31
Montelukast Sodium
31 claims
| Drug | Claims |
|---|---|
| Symbicort Budesonide/Formoterol Fumarate | 190 |
| Azelastine Hcl | 128 |
| Ipratropium Bromide | 59 |
| Spiriva Respimat Tiotropium Bromide | 57 |
| Omeprazole | 55 |
| Fluticasone Propionate | 51 |
| Dupixent Pen Dupilumab | 40 |
| Montelukast Sodium | 31 |
| Budesonide-Formoterol Fumarate Budesonide/Formoterol Fumarate | 25 |
| Epinephrine | 24 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Allergy & Immunology (Internal Medicine) Physician in CA →
All providers in California →
Compare specialties →
Allergy & Immunology (Internal Medicine) Physician Overview
How Rosemary Hallett, M.D. fits within the Allergy & Immunology (Internal Medicine) Physician landscape nationally.
520
Allergy & Immunology (Internal Medicine) Physician Providers in US
48
States with Allergy & Immunology (Internal Medicine) Physician
798
Avg Claims per Provider
Rosemary Hallett, M.D.'s 906 claims are above the specialty average of 798.
Nearby Allergy & Immunology (Internal Medicine) Physician Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Hallett.
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 California medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Allergy & Immunology (Internal Medicine) 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.
Healthcare Guides
Learn more about finding, verifying, and understanding healthcare providers.
How to Find a Doctor
Step-by-step guide to choosing a provider
Verify Credentials
Check NPI, board certification & license status
Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore California
Frequently Asked Questions
What is Rosemary Hallett, M.D.'s specialty? ▼
Rosemary Hallett, M.D. specializes in Allergy & Immunology (Internal Medicine) Physician and practices in Davis, California. Credentials: M.D..
How much does Rosemary Hallett, M.D. prescribe under Medicare Part D? ▼
In 2023, Rosemary Hallett, M.D. wrote 906 Medicare Part D claims totaling $1.1M in drug costs for 194 beneficiaries.
Where is Rosemary Hallett, M.D. located? ▼
Rosemary Hallett, M.D. is located at 451 E. HEALTH SCIENCES DR, Davis, CA, 95616. Phone: (530) 752-2884.
What is Rosemary Hallett, M.D.'s NPI number? ▼
Rosemary Hallett, M.D.'s National Provider Identifier (NPI) is 1376527804, issued on 11/29/2005.
Does Rosemary Hallett, M.D. prescribe more brand-name or generic drugs? ▼
Rosemary Hallett, M.D.'s prescribing is 54% brand-name and 46% generic drugs by claim count, with $1.1M in brand drug costs.
How many Allergy & Immunology (Internal Medicine) Physician providers are there in the US? ▼
There are 520 Allergy & Immunology (Internal Medicine) Physician providers across 48 states in the US. The average Allergy & Immunology (Internal Medicine) Physician provider writes 798 Medicare Part D claims per year.
What drugs does Rosemary Hallett, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Rosemary Hallett, M.D.'s most frequently prescribed drugs include Symbicort, Azelastine Hcl, Ipratropium Bromide. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Rosemary Hallett, M.D. accept Medicare? ▼
Rosemary Hallett, M.D. appears in CMS Medicare data with 906 Part D claims and 194 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Rosemary Hallett, M.D.'s credentials? ▼
Rosemary Hallett, M.D.'s NPI is 1376527804 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.