NPI registry status
Active
2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1043721632 MD
Verify on CMS → Doriann Klaassen, MD
Endocrinology, Diabetes & Metabolism Physician in Hyannis, Massachusetts.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 8,078 in Endocrinology, Diabetes & Metabolism 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
568
Medicare Part D claims · 111 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
27%
generic claims · 64% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$349.94
10 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
Doriann Klaassen, MD filed 568 Medicare Part D claims in 2024 as an Endocrinology, Diabetes & Metabolism Physician in Hyannis, Massachusetts, prescribing 27% generic.
- 568
- Part D claims, 2024
- 27%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥65th
- 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 Doriann Klaassen, MD
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 1043721632), first enumerated 10/23/2017.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 568 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
- Reported
Industry payment transparency
$349.94 in reported industry payments (10 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- State context
State board disciplinary context
Massachusetts statewide board action statistics are published annually — these figures describe aggregate state activity, not Doriann Klaassen, MD's individual license status. Verify directly with the state medical board.
Source: BORIM annual report 2023
- 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 1043721632 · Endocrinology, Diabetes & Metabolism Physician
NPI-10 · ENUM-RECENT · TAX-MID · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1043721632
- ENUM-RECENT 2017
- TAX-MID 8K Endocrinology, Diabetes
- RX-LIGHT 568
- BOOK-THIN 373 in Massachusetts
- PHOTO-ENUM Ahmed Elsherif · 2017
Doriann Klaassen, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
568 ≥ 65th percentile 65% 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)
Doriann Klaassen, 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 Doriann Klaassen, MD?
Quality data not reportedPrimary specialty
Endocrinology, Diabetes & Metabolism Physician
Medicare Part D claims
568 79% vs specialty avg
Specialty distribution in Massachusetts
How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among Massachusetts 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 Endocrinology, Diabetes & Metabolism 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 | 1043721632 |
|---|---|
| Specialty | Endocrinology, Diabetes & Metabolism Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 10/23/2017 |
Hospital and facility affiliations
Facilities where Doriann Klaassen, 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.
Medical Affiliates OF Cape Cod Inc
Hyannis, MA
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 Doriann Klaassen, MD. Source: openpaymentsdata.cms.gov.
Total received
$350
Largest payer
BETA BIONICS, INC.
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.
License & disciplinary context - Massachusetts BORIM 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 ~38K Massachusetts medical licensees in 2023 - they are NOT specific to Doriann Klaassen, MD. To verify Doriann Klaassen, MD's current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases
BORIM 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 Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Brand-heavy
Doriann Klaassen, MD - brand share 64.0%
Endocrinology, Diabetes & Metabolism Physician average
64% brand-name claims vs 27% generic, on 568 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.
568
Total Claims
$287K
Total Drug Cost
111
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 979.1
- Total Day Supply
- 28,691
- Brand vs Generic
- 64% brand / 27% generic
- Brand Drug Cost
- $273K
- Generic Drug Cost
- $2K
Patient Demographics
- Average Patient Age
- 67.8 years
- Avg HCC Risk Score
- 2.29
- Gender Split
- 55% female / 45% male
- Age Distribution
- <65: 24, 65-74: 60, 75-84: N/A, 85+: N/A
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Doriann Klaassen, MD prescribes most
Top Medicare Part D drugs by claim count, 2024
- Ozempic
Ozempic
66 claims
- Levothyroxine Sodium
Levothyroxine Sodium
42 claims
- Jardiance
Jardiance
40 claims
- Mounjaro
Mounjaro
37 claims
- Synthroid
Synthroid
34 claims
- Trulicity 24
Trulicity
24 claims
- Lantus Solostar 22
Lantus Solostar
22 claims
- Hydrocortisone 20
Hydrocortisone
20 claims
| Drug | Claims |
|---|---|
| Ozempic Semaglutide | 66 |
| Levothyroxine Sodium | 42 |
| Jardiance Empagliflozin | 40 |
| Mounjaro Tirzepatide | 37 |
| Synthroid Levothyroxine Sodium | 34 |
| Trulicity Dulaglutide | 24 |
| Lantus Solostar Insulin Glargine,hum.Rec.Anlog | 22 |
| Hydrocortisone | 20 |
| Farxiga Dapagliflozin Propanediol | 18 |
| Omnipod 5 Dexg7g6 Pods (Gen 5) Insulin Pump Cart,auto,bt,g6/7 | 17 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Endocrinology, Diabetes & Metabolism Physician in MA →
All providers in Massachusetts →
Compare specialties →
Endocrinology, Diabetes & Metabolism Physician Overview
How Doriann Klaassen, MD fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.
8,078
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,739
Avg Claims per Provider
Doriann Klaassen, MD's 568 claims are below the specialty average of 2,739.
Nationwide Endocrinology, Diabetes & Metabolism Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Klaassen, both outside Massachusetts so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2017)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Endocrinology, Diabetes & Metabolism Physician Providers in Massachusetts
Other clinicians with the same primary specialty enrolled in Massachusetts, drawn from the same CMS NPPES roster as Klaassen.
One of 373 Endocrinology, Diabetes & Metabolism Physician providers enrolled in Massachusetts, 5 are shown here.
Dr. Alice Abbott
MD
Leeds, MA
Dr. Adham Abdel Mottalib
MD
Boston, MA
Dr. Martin Abrahamson
M.D.
Boston, MA
Dr. Ana Paula Abreu Metzger
M.D., PHD
Boston, MA
Gail Adler
MD PHD
Boston, MA
Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Doriann Klaassen, MD's specialty? ▼
Doriann Klaassen, MD specializes in Endocrinology, Diabetes & Metabolism Physician and practices in Hyannis, Massachusetts. Credentials: MD.
How much does Doriann Klaassen, MD prescribe under Medicare Part D? ▼
In 2024, Doriann Klaassen, MD wrote 568 Medicare Part D claims totaling $287K in drug costs for 111 beneficiaries.
Where is Doriann Klaassen, MD located? ▼
Doriann Klaassen, MD is located at 1030 FALMOUTH RD # 201, Hyannis, MA, 02601. Phone: (774) 470-5080.
What is Doriann Klaassen, MD's NPI number? ▼
Doriann Klaassen, MD's National Provider Identifier (NPI) is 1043721632, issued on 10/23/2017.
Does Doriann Klaassen, MD prescribe more brand-name or generic drugs? ▼
Doriann Klaassen, MD's prescribing is 64% brand-name and 27% generic drugs by claim count, with $273K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US? ▼
There are 8,078 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,739 Medicare Part D claims per year.
What drugs does Doriann Klaassen, MD prescribe most often? ▼
Based on 2024 Medicare Part D data, Doriann Klaassen, MD's most frequently prescribed drugs include Ozempic, Levothyroxine Sodium, Jardiance. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Doriann Klaassen, MD accept Medicare? ▼
Doriann Klaassen, MD appears in CMS Medicare data with 568 Part D claims and 111 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Doriann Klaassen, MD's credentials? ▼
Doriann Klaassen, MD's NPI is 1043721632 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 (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.