Leonard R. Zemel, M.D.
Endocrinology, Diabetes & Metabolism Physician · Denver, CO
Leonard R. Zemel, M.D. is an endocrinology, diabetes & metabolism physician with a practice address in Denver, Colorado, and NPI 1447256045, issued on Jun 28, 2005. Check the license (Colorado 27647, as entered in NPPES) on the Colorado Medical Board; the Medicare figures below come from public CMS files.
- Name
- Leonard R. Zemel
- Credential
- M.D.
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License number
- 27647 CO
Self-reported in NPPES; status is on the state search - Practice location
- 3464 S Willow St, Denver, CO 80231
- Phone
- (303) 755-2900
- Enumerated
- Jun 28, 2005
- Record last updated
- Nov 13, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (303) 755-0404
- Medicaid ID
- 01276476 CO
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 149 in Colorado → Look up another NPI →
Also registered at 3464 S Willow St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Guinevere Sarnecki, O. T.Occupational Therapist1942383849
- Michael Willig, MDFamily Medicine Physician1639253156
Verify Leonard R. Zemel in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersColorado Medical Board
Search for license 27647Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
90% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
270 Medicare Part D claims for 95 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D. Brand-name drugs were 27% of claims.
Most prescribed
- Levothyroxine Sodium38 claims
- Atorvastatin Calcium22 claims
- Metformin Hcl20 claims
- Ozempic14 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: $120.82
1 payment: food and beverage; the largest payer was Sanofi-Aventis U.S. LLC. 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.
Leonard R. Zemel among 149 endocrinology, diabetes & metabolism physician records in Colorado
Leonard R. Zemel, M.D. is one of 149 endocrinology, diabetes & metabolism physician records with a practice address in Colorado. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 92% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileNo · 72% of these records are
- Record last updated2007 · 62% 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 Colorado 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 Colorado
There are 149 endocrinology, diabetes & metabolism physician records in Colorado.
All 149 in Colorado → Every provider in Denver → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Jennifer Bernard, M.D.Lakewood, CO 802281275706285
- Alexandra Reiher, MDLakewood, CO 802281700046018
- Rachana Thapa, MDLakewood, CO 802281962714907
- Daniel Citron, M.D.Denver, CO 802201861442410
- Alex Goldsmith, M.D.Denver, CO 802201417907064
- Romana Haas, MDDenver, CO 802201386739258
- Nirmala Kumar, MDDenver, CO 802201619059144
- Mervyn Lifschitz, M.D.Denver, CO 802201639267636
Common questions
What is Leonard R. Zemel, M.D.'s NPI number?
Leonard R. Zemel, M.D.'s National Provider Identifier (NPI) is 1447256045, issued on Jun 28, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Leonard R. Zemel, M.D. located?
The NPPES record lists a practice address at 3464 S Willow St, Denver, CO, 80231. Phone: (303) 755-2900. Providers update this record themselves, so call before visiting.
How can I verify Leonard R. Zemel, M.D.'s license?
NPPES lists Colorado license number 27647, as entered by the provider. Search the Colorado Medical Board at https://dpo.colorado.gov/Medical. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Leonard R. Zemel, M.D. prescribe under Medicare Part D?
In 2024, Leonard R. Zemel, M.D. had 270 Medicare Part D claims for 95 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.