NPI registry status
Active
2026 NPPES data Allergy & Immunology (Internal Medicine) Physician NPI 1366429573 M.D.
Verify on CMS → John Hagan, M.D.
Allergy & Immunology (Internal Medicine) Physician in Rochester, Minnesota.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 528 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
339
Medicare Part D claims · 79 beneficiaries · Allergy & Immunology (Internal Medicine) Physician avg: 835
Generic prescribing
48%
generic claims · 52% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
John Hagan, M.D. filed 339 Medicare Part D claims in 2024 as an Allergy & Immunology (Internal Medicine) Physician in Rochester, Minnesota, prescribing 48% generic.
- 339
- Part D claims, 2024
- 48%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥56th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about John Hagan, M.D.
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1366429573), first enumerated 12/29/2005.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 339 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1366429573 · Allergy & Immunology (Internal Medicine) Physician
NPI-10 · ENUM-LEGACY · TAX-NARROW · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1366429573
- ENUM-LEGACY 2005
- TAX-NARROW 528
- RX-LIGHT 339
- BOOK-THIN 14 in Minnesota
- PHOTO-ENUM Robert Czarnecki · 2005
John Hagan, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
339 ≥ 56th percentile 56% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
John Hagan, 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 John Hagan, M.D.?
Quality data not reportedPrimary specialty
Allergy & Immunology (Internal Medicine) Physician
Medicare Part D claims
339 59% vs specialty avg
Specialty distribution in Minnesota
How Allergy & Immunology (Internal Medicine) Physician compares to other specialties among Minnesota 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).
Practice Address
Provider Details
| NPI | 1366429573 |
|---|---|
| Specialty | Allergy & Immunology (Internal Medicine) Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 12/29/2005 |
Hospital and facility affiliations
Facilities where John Hagan, 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.
Mayo Clinic
Rochester, MN
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Brand-heavy
John Hagan, M.D. - brand share 52.0%
Allergy & Immunology (Internal Medicine) Physician average
52% brand-name claims vs 48% generic, on 339 2024 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 2024.
339
Total Claims
$403K
Total Drug Cost
79
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 534.233
- Total Day Supply
- 14,816
- Brand vs Generic
- 52% brand / 48% generic
- Brand Drug Cost
- $388K
- Generic Drug Cost
- $15K
- Antibiotic Claims
- 16
Patient Demographics
- Average Patient Age
- 73.6 years
- Avg HCC Risk Score
- 1.13
- Gender Split
- 53% female / 47% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What John Hagan, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Montelukast Sodium
Montelukast Sodium
49 claims
- Albuterol Sulfate …
Albuterol Sulfate Hfa
33 claims
- Alvesco
Alvesco
20 claims
- Breo Ellipta
Breo Ellipta
20 claims
- Azelastine Hcl 19
Azelastine Hcl
19 claims
- Advair Hfa 18
Advair Hfa
18 claims
- Fluticasone-Salmet… 18
Fluticasone-Salmeterol
18 claims
- Ipratropium Bromide 17
Ipratropium Bromide
17 claims
| Drug | Claims |
|---|---|
| Montelukast Sodium | 49 |
| Albuterol Sulfate Hfa Albuterol Sulfate | 33 |
| Alvesco Ciclesonide | 20 |
| Breo Ellipta Fluticasone/Vilanterol | 20 |
| Azelastine Hcl | 19 |
| Advair Hfa Fluticasone Propion/Salmeterol | 18 |
| Fluticasone-Salmeterol Fluticasone Propion/Salmeterol | 18 |
| Ipratropium Bromide | 17 |
| Prednisone | 16 |
| Dulera Mometasone/Formoterol | 13 |
* 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 MN →
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Allergy & Immunology (Internal Medicine) Physician Overview
How John Hagan, M.D. fits within the Allergy & Immunology (Internal Medicine) Physician landscape nationally.
528
Allergy & Immunology (Internal Medicine) Physician Providers in US
47
States with Allergy & Immunology (Internal Medicine) Physician
835
Avg Claims per Provider
John Hagan, M.D.'s 339 claims are below the specialty average of 835.
Nationwide Allergy & Immunology (Internal Medicine) Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Hagan, both outside Minnesota so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2005)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Allergy & Immunology (Internal Medicine) Physician Providers in Minnesota
Other clinicians with the same primary specialty enrolled in Minnesota, drawn from the same CMS NPPES roster as Hagan.
One of 14 Allergy & Immunology (Internal Medicine) Physician providers enrolled in Minnesota, 5 are shown here.
Frequently Asked Questions
What is John Hagan, M.D.'s specialty? ▼
John Hagan, M.D. specializes in Allergy & Immunology (Internal Medicine) Physician and practices in Rochester, Minnesota. Credentials: M.D..
How much does John Hagan, M.D. prescribe under Medicare Part D? ▼
In 2024, John Hagan, M.D. wrote 339 Medicare Part D claims totaling $403K in drug costs for 79 beneficiaries.
Where is John Hagan, M.D. located? ▼
John Hagan, M.D. is located at 200 1ST ST SW, Rochester, MN, 55905. Phone: (507) 284-2511.
What is John Hagan, M.D.'s NPI number? ▼
John Hagan, M.D.'s National Provider Identifier (NPI) is 1366429573, issued on 12/29/2005.
Does John Hagan, M.D. prescribe more brand-name or generic drugs? ▼
John Hagan, M.D.'s prescribing is 52% brand-name and 48% generic drugs by claim count, with $388K in brand drug costs.
How many Allergy & Immunology (Internal Medicine) Physician providers are there in the US? ▼
There are 528 Allergy & Immunology (Internal Medicine) Physician providers across 47 states in the US. The average Allergy & Immunology (Internal Medicine) Physician provider writes 835 Medicare Part D claims per year.
What drugs does John Hagan, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, John Hagan, M.D.'s most frequently prescribed drugs include Montelukast Sodium, Albuterol Sulfate Hfa, Alvesco. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does John Hagan, M.D. accept Medicare? ▼
John Hagan, M.D. appears in CMS Medicare data with 339 Part D claims and 79 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify John Hagan, M.D.'s credentials? ▼
John Hagan, M.D.'s NPI is 1366429573 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 (2024). 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 August 2026 (NPPES) / 2024 (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
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 August 2026.