NPI registry status
Active
2026 NPPES data Allergy & Immunology Physician NPI 1255536553 MD
Verify on CMS → Jonathon Posthumus, MD
Allergy & Immunology Physician in Fredericksburg, Virginia.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 3,390 in Allergy & Immunology 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
814
Medicare Part D claims · 138 beneficiaries · Allergy & Immunology Physician avg: 764
Generic prescribing
59%
generic claims · 41% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.3K
63 payments · CMS Open Payments (Sunshine Act)
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
Jonathon Posthumus, MD filed 814 Medicare Part D claims in 2023 as a Allergy & Immunology Physician in Fredericksburg, Virginia, prescribing 59% generic.
- 814
- Part D claims, 2023
- 59%
- 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.
Jonathon Posthumus, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
814 Top 27% higher than 73% 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)
Jonathon Posthumus, MD 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 Jonathon Posthumus, MD?
Quality data not reportedPrimary specialty
Allergy & Immunology Physician
Medicare Part D claims
814 7% vs specialty avg
Specialty distribution in Virginia
How Allergy & Immunology Physician compares to other specialties among Virginia 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 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).
Jonathon Posthumus, MD appears in the CMS NPPES registry as a Allergy & Immunology Physician provider holding MD credentials at 511 PARK HILL DR, Fredericksburg, VA, 22401, with a listed phone of (540) 371-5660. NPI 1255536553 was issued on 06/18/2007.
Medicare Part D records for calendar year 2023 show 814 prescription claims written by this provider, covering 138 Medicare beneficiaries and totaling roughly $285K in drug spend, split 41% brand-name and 59% generic by claim count.
Allergy & Immunology Physician is a narrow specialty nationwide, with 3,390 enrolled providers across 52 states and an average of 764 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 | 1255536553 |
|---|---|
| Specialty | Allergy & Immunology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 06/18/2007 |
Hospital and facility affiliations
Facilities where Jonathon Posthumus, 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.
Allergy Partners PLLC
Fredericksburg, VA
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Jonathon Posthumus, MD. Source: openpaymentsdata.cms.gov.
Total received
$1.3K
Largest payer
AstraZeneca Pharmaceuticals LP
Most common payment type
Food and Beverage
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
Brand vs generic prescribing mix · Above average
Jonathon Posthumus, MD - brand share 41.0%
Allergy & Immunology Physician average
41% brand-name claims vs 59% generic, on 814 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.
814
Total Claims
$285K
Total Drug Cost
138
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,242
- Total Day Supply
- 33,546
- Brand vs Generic
- 41% brand / 59% generic
- Brand Drug Cost
- $262K
- Generic Drug Cost
- $23K
- Antibiotic Claims
- 28
Patient Demographics
- Average Patient Age
- 70.8 years
- Avg HCC Risk Score
- 1.00
- Gender Split
- 72% female / 28% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Jonathon Posthumus, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Montelukast Sodium
Montelukast Sodium
86 claims
- Albuterol Sulfate …
Albuterol Sulfate Hfa
81 claims
- Azelastine Hcl
Azelastine Hcl
74 claims
- Prednisone
Prednisone
54 claims
- Epinephrine
Epinephrine
46 claims
- Fluticasone Propio…
Fluticasone Propionate
41 claims
- Ipratropium Bromide
Ipratropium Bromide
41 claims
- Advair Hfa
Advair Hfa
39 claims
| Drug | Claims |
|---|---|
| Montelukast Sodium | 86 |
| Albuterol Sulfate Hfa Albuterol Sulfate | 81 |
| Azelastine Hcl | 74 |
| Prednisone | 54 |
| Epinephrine | 46 |
| Fluticasone Propionate | 41 |
| Ipratropium Bromide | 41 |
| Advair Hfa Fluticasone Propion/Salmeterol | 39 |
| Symbicort Budesonide/Formoterol Fumarate | 34 |
| Arnuity Ellipta Fluticasone Furoate | 26 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Allergy & Immunology Physician Overview
How Jonathon Posthumus, MD fits within the Allergy & Immunology Physician landscape nationally.
3,390
Allergy & Immunology Physician Providers in US
52
States with Allergy & Immunology Physician
764
Avg Claims per Provider
Jonathon Posthumus, MD's 814 claims are above the specialty average of 764.
Nearby Allergy & Immunology Physician Providers in Virginia
Other clinicians with the same primary specialty enrolled in Virginia, drawn from the same CMS NPPES roster as Posthumus.
Dr. Parasmani Acharya
M.D.
Pulaski, VA
Veronica Alix
Hampton, VA
Dr. Darshana Alle
M.D.
Henrico, VA
Dr. Oral Alpan
MD
Springfield, VA
Dr. Donald Asbury
MD
Bluefield, VA
Compare Allergy & Immunology 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 Virginia medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Allergy & Immunology 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 Jonathon Posthumus, MD's specialty? ▼
Jonathon Posthumus, MD specializes in Allergy & Immunology Physician and practices in Fredericksburg, Virginia. Credentials: MD.
How much does Jonathon Posthumus, MD prescribe under Medicare Part D? ▼
In 2023, Jonathon Posthumus, MD wrote 814 Medicare Part D claims totaling $285K in drug costs for 138 beneficiaries.
Where is Jonathon Posthumus, MD located? ▼
Jonathon Posthumus, MD is located at 511 PARK HILL DR, Fredericksburg, VA, 22401. Phone: (540) 371-5660.
What is Jonathon Posthumus, MD's NPI number? ▼
Jonathon Posthumus, MD's National Provider Identifier (NPI) is 1255536553, issued on 06/18/2007.
Does Jonathon Posthumus, MD prescribe more brand-name or generic drugs? ▼
Jonathon Posthumus, MD's prescribing is 41% brand-name and 59% generic drugs by claim count, with $262K in brand drug costs.
How many Allergy & Immunology Physician providers are there in the US? ▼
There are 3,390 Allergy & Immunology Physician providers across 52 states in the US. The average Allergy & Immunology Physician provider writes 764 Medicare Part D claims per year.
What drugs does Jonathon Posthumus, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Jonathon Posthumus, MD's most frequently prescribed drugs include Montelukast Sodium, Albuterol Sulfate Hfa, Azelastine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Jonathon Posthumus, MD accept Medicare? ▼
Jonathon Posthumus, MD appears in CMS Medicare data with 814 Part D claims and 138 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Jonathon Posthumus, MD's credentials? ▼
Jonathon Posthumus, MD's NPI is 1255536553 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
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.