Doriann Klaassen, MD
Endocrinology, Diabetes & Metabolism Physician · Hyannis, MA
Doriann Klaassen, MD is an endocrinology, diabetes & metabolism physician with a practice address in Hyannis, Massachusetts, and NPI 1043721632, issued on Oct 23, 2017. Check the license (Massachusetts 1020815, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Doriann Klaassen
- Credential
- MD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License number
- 1020815 MA
Self-reported in NPPES; status is on the state search - Practice location
- 1030 Falmouth RD # 201, Hyannis, MA 02601
- Phone
- (774) 470-5080
- Enumerated
- Oct 23, 2017
- Record last updated
- Feb 5, 2025
- Medicare enrollment
- Enrolled (PECOS I20241011003898); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 522 in Massachusetts → Look up another NPI →
Also registered at 1030 Falmouth RD # 201
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Marlene Marte Furment, MDRheumatology Physician1376195123
Verify Doriann Klaassen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 1020815Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
78% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
568 Medicare Part D claims for 111 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D. Brand-name drugs were 64% of claims.
Most prescribed
- Ozempic66 claims
- Levothyroxine Sodium42 claims
- Jardiance40 claims
- Mounjaro37 claims
- Synthroid34 claims
- Trulicity24 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $349.94
10 payments; by number, the most common kind was food and beverage; the largest payer was Beta Bionics, Inc. The 5,661 providers of this specialty with any payment received $5,742.15 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Medical Affiliates OF Cape Cod IncHyannis, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Doriann Klaassen among 522 endocrinology, diabetes & metabolism physician records in Massachusetts
Doriann Klaassen, MD is one of 522 endocrinology, diabetes & metabolism physician records with a practice address in Massachusetts. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 88% of them.
- NPI issued2017 · 88% of these records are older, 10% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2018 · median 2002 among the 378 with a school on file
- Record last updated2025 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RE0101X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Endocrinology, Diabetes & Metabolism Physician providers in Massachusetts
There are 522 endocrinology, diabetes & metabolism physician records in Massachusetts.
All 522 in Massachusetts → Every provider in Hyannis → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Nathaniel Clark, MDHyannis, MA 026011386687234
- Mary Crowell, MDHyannis, MA 026011003854365
- Catalina Norman, MD, PHDHyannis, MA 026011831374107
- Wingyee Wan, MDHyannis, MA 026011922468164
- Ziad Farah, MDHarwich, MA 026451700854619
- Zona Batacchi, M.D.Harwich Port, MA 026461629352869
- John Coughlin, MDFalmouth, MA 025401275583932
- Jennifer Patten, M.D.South Yarmouth, MA 026641891720546
Common questions
What is Doriann Klaassen, MD's NPI number?
Doriann Klaassen, MD's National Provider Identifier (NPI) is 1043721632, issued on Oct 23, 2017. An NPI identifies a provider in billing; it is not a license.
Where is Doriann Klaassen, MD located?
The NPPES record lists a practice address at 1030 Falmouth RD # 201, Hyannis, MA, 02601. Phone: (774) 470-5080. Providers update this record themselves, so call before visiting.
How can I verify Doriann Klaassen, MD's license?
NPPES lists Massachusetts license number 1020815, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Doriann Klaassen, MD prescribe under Medicare Part D?
In 2024, Doriann Klaassen, MD had 568 Medicare Part D claims for 111 beneficiaries; the average among endocrinology, diabetes & metabolism physician prescribers was 2,630. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.