Harold S. Nelson, MD
Allergy & Immunology Physician · Denver, CO
Harold S. Nelson, MD is an allergy & immunology physician with a practice address in Denver, Colorado, and NPI 1104916873, issued on Oct 13, 2006. Check the license (Colorado 18391, as entered in NPPES) on the Colorado Medical Board; the Medicare figures below come from public CMS files.
- Name
- Harold S. Nelson
- Credential
- MD
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License number
- 18391 CO
Self-reported in NPPES; status is on the state search - Practice location
- 1400 Jackson St, Denver, CO 80206
- Phone
- (303) 388-4461
- Enumerated
- Oct 13, 2006
- Record last updated
- Nov 12, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (303) 270-2174
- Medicaid ID
- 01183912 CO
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 102 in Colorado → Look up another NPI →
Also registered at 1400 Jackson St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Ronya Ajeel, APN-CRNACertified Registered Nurse Anesthetist1184279044
- Akrum Al-Zubaidi, D.O.Pulmonary Disease Physician1649426222
- Rafeul Alam, MDAllergy & Immunology Physician1790730687
- Jon Allison, PACMedical Physician Assistant1609812668
- Vivianne Allsop, MDRheumatology Physician1215499603
- Mark Aloia, MDPsychiatry Physician1295842607
Verify Harold S. Nelson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersColorado Medical Board
Search for license 18391Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $251.13
2 payments; by number, the most common kind was food and beverage; the largest payer was Grifols USA, LLC. The 2,496 providers of this specialty with any payment received $8,321.81 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.
Harold S. Nelson among 102 allergy & immunology physician records in Colorado
Harold S. Nelson, MD is one of 102 allergy & immunology physician records with a practice address in Colorado. 70% 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 13% of them.
- NPI issued2006 · 13% of these records are older, 54% newer
- In a Medicare fileYes · 70% of these records are
- In the CMS Doctors and Clinicians fileNo · 54% of these records are
- Record last updated2020 · 72% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a Colorado practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in Colorado
There are 102 allergy & immunology physician records in Colorado.
All 102 in Colorado → Every provider in Denver → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Rafeul Alam, MDDenver, CO 802061790730687
- Donna Bratton, MDDenver, CO 802061972536910
- Christine Cho, MDDenver, CO 802061144494196
- Ronina Covar, MDDenver, CO 802061477643229
- Rohit Katial, MDDenver, CO 802061750463303
- Bruce Lanser, MDDenver, CO 802061427299379
- Donald Leung, MDDenver, CO 802061215012950
- Kanao Otsu, M.D.Denver, CO 802061881748226
Common questions
What is Harold S. Nelson, MD's NPI number?
Harold S. Nelson, MD's National Provider Identifier (NPI) is 1104916873, issued on Oct 13, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Harold S. Nelson, MD located?
The NPPES record lists a practice address at 1400 Jackson St, Denver, CO, 80206. Phone: (303) 388-4461. Providers update this record themselves, so call before visiting.
How can I verify Harold S. Nelson, MD's license?
NPPES lists Colorado license number 18391, 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.
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.