Diana L. Maas, MD
Endocrinology, Diabetes & Metabolism Physician · Milwaukee, WI
Diana L. Maas, MD is an endocrinology, diabetes & metabolism physician with a practice address in Milwaukee, Wisconsin, and NPI 1427009273, issued on May 15, 2006. Check the license (Wisconsin 27716, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Diana L. Maas
- Credential
- MD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License number
- 27716 WI
Self-reported in NPPES; status is on the state search - Practice location
- Froedtert & Med College Clin - East, Milwaukee, WI 53226
- Phone
- (414) 805-3666
- Enumerated
- May 15, 2006
- Record last updated
- Jul 24, 2019 (not updated in 7 years: call before relying on the address or phone)
- Medicaid ID
- 1427009273 WI
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 187 in Wisconsin → Look up another NPI →
Also registered at Froedtert & Med College Clin - East
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Jasna Jevtic, MDInternal Medicine Physician1386695823
- Michael Keelan, MDCardiovascular Disease Physician1275584013
- Feng Lu, MDPhysical Medicine & Rehabilitation Physician1720039571
Verify Diana L. Maas in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 27716Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
87% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
336 Medicare Part D claims for 130 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D. Brand-name drugs were 46% of claims.
Most prescribed
- Levothyroxine Sodium105 claims
- Hydrocortisone51 claims
- Synthroid51 claims
- Cabergoline12 claims
- Fludrocortisone Acetate11 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 80.5 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Diana L. Maas among 187 endocrinology, diabetes & metabolism physician records in Wisconsin
Diana L. Maas, MD is one of 187 endocrinology, diabetes & metabolism physician records with a practice address in Wisconsin. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 9% of them.
- NPI issued2006 · 9% of these records are older, 55% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileNo · 72% of these records are
- Record last updated2019 · 48% 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 Wisconsin 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 Wisconsin
There are 187 endocrinology, diabetes & metabolism physician records in Wisconsin.
All 187 in Wisconsin → Every provider in Milwaukee → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Adrienne Barnosky, D.O.Wauwatosa, WI 532261215149414
- Robert Blank, MD PHDMilwaukee, WI 532261326015009
- Gilbert Fareau, M.D.Milwaukee, WI 532261225221138
- Adriana Ioachimescu, MDMilwaukee, WI 532261437183621
- Albert Jochen, MDMilwaukee, WI 532261720030513
- Thomas Kelly, M.D.Wauwatosa, WI 532261093823130
- Srividya Kidambi, M.D.Milwaukee, WI 532261376614446
- Paul Knudson, MDMilwaukee, WI 532261417908252
Common questions
What is Diana L. Maas, MD's NPI number?
Diana L. Maas, MD's National Provider Identifier (NPI) is 1427009273, issued on May 15, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Diana L. Maas, MD located?
The NPPES record lists a practice address at Froedtert & Med College Clin - East, Milwaukee, WI, 53226. Phone: (414) 805-3666. Providers update this record themselves, so call before visiting.
How can I verify Diana L. Maas, MD's license?
NPPES lists Wisconsin license number 27716, as entered by the provider. Search the Wisconsin Medical Examining Board at https://dsps.wi.gov/Pages/BoardsCouncils/MEB/Default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Diana L. Maas, MD prescribe under Medicare Part D?
In 2024, Diana L. Maas, MD had 336 Medicare Part D claims for 130 beneficiaries; the average among endocrinology, diabetes & metabolism physician prescribers was 2,630. Part D covers Medicare prescriptions only.
What is Diana L. Maas, MD's MIPS final score?
The 2023 MIPS final score is 80.5 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.