Dr. Nathan E. Riddell, MD
- Medicare services, 2024
- 2,171
- Medicare patients, 2024
- 1,464
- Part D claims, 2024
- 1,331
- Hospital affiliations
- 3
- Industry payments
- $6,636
- Practice address
- 295 Varnum Avenue, Lowell, MA 01854
- Practice phone
- Call (978) 937-6000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Riddell's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Nathan E. Riddell is an internist in Lowell, Massachusetts
Dr. Riddell practices at Lowell General Hospital in Lowell, Massachusetts, part of Tufts Medicine.
Dr. Riddell's NPI, 1245670983, was assigned on June 26, 2013. Dr. Riddell holds Massachusetts license 256554.
- NPI
- 1245670983NPI Registry (opens in a new tab)
- Medicare PAC ID
- 2062643489
- NPI enumeration date
- June 26, 2013
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (978) 937-6000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 39
- Medical school graduation
- 2013
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Nathan E. Riddell practices at Lowell General Hospital in Lowell, Massachusetts
Dr. Riddell's primary practice is Lowell General Hospital, at 295 Varnum Avenue, Lowell, MA 01854 in Middlesex County. The practice phone is (978) 937-6000.
- Lowell General Hospital295 Varnum Avenue, Lowell, MA 01854 · Middlesex CountyPhone(978) 937-6000
Source: Dmand AI Affiliation Data
Dr. Nathan E. Riddell is affiliated with 4 sites of care and 4 medical groups
Dr. Riddell's primary practice is Lowell General Hospital in Lowell, Massachusetts, part of Tufts Medicine. Dr. Riddell is also affiliated with UMass Memorial Medical Center - University Campus. The medical group on file is Steward Medical Group. Dmand AI also links Dr. Riddell to 1 more hospital, 3 medical groups and 1 group practice or clinic, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Nathan E. Riddell's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Riddell practices, 4 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Lowell General Hospital | Available with a free account |
| +3 more sites and 3 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Nathan E. Riddell is one of 5,528 internists in Massachusetts
Internal medicine is Dr. Riddell's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Riddell is licensed in Massachusetts.
Specialties and state licenses
- Internal medicine, MassachusettsPrimary
Internists near Dr. Riddell
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Nathan E. Riddell billed Medicare for 2,171 services in 2024
CMS data shows 2,171 Medicare services from Dr. Riddell across 25 procedure codes in 2024, for 1,464 Medicare patients. Medicare paid $120,881 for them.
Dr. Riddell's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Tests and treatments
- 2023: 1,3382024: 1,62421%
- Office and hospital visits
- 2023: 4672024: 4513%
- Other services
- 2023: 312024: 5681%
- Surgery
- 2023: 172024: 2547%
- Imaging
- 2023: 182024: 1517%
- Drugs given in the office
- 2023: 392024: 0100%
Where Dr. Riddell's Medicare services took place, 2024
- In an office54625%
- In a facility1,62575%
Dr. Riddell compared with the Massachusetts median for internists, 2024
- Dr. Riddell
- Massachusetts median
- Medicare services
- 2,171vs 4315.0 times
- Medicare patients
- 1,464vs 1947.5 times
- Part D claims
- 1,219vs 4023.0 times
Medians across 5,369 internists in Massachusetts with Dmand AI profiles that report each measure.
Dr. Riddell's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Nathan E. Riddell treated 1,464 Medicare patients in 2024, average age 76
CMS counts 1,464 Medicare patients who saw Dr. Riddell in 2024. The largest group is 75 to 84, with 522 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 32% are also on Medicaid. Their average risk score is 1.82, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Riddell's median patient age at 69, with 47% women.
Dr. Riddell's Medicare patients by age, 2024
Dr. Riddell's Medicare patients by sex, 2024
- Women74251%
- Men72249%
Chronic conditions among Dr. Riddell's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Ischemic heart disease55%
- Heart failure48%
- Chronic kidney disease47%
- Arthritis46%
- Diabetes41%
- Atrial fibrillation40%
Share of Medicare patients with each condition. A patient can have several.
Dr. Riddell's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 69
Patient panel by sex, all payers
- Women47%
- Men53%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Nathan E. Riddell wrote 1,331 Medicare Part D claims in 2024
In 2024, Dr. Riddell wrote 1,331 Medicare Part D claims for 235 patients. 88% of them were for generic drugs. CMS names the drug for 1,219 of them, across 25 drugs with 11 or more claims each, at $155,611 in total drug cost. In 2023, CMS named 840 claims across 20 drugs.
Dr. Riddell's Part D claims by kind of drug, 2024
- Generic1,173 claims88%
- Brand-name158 claims12%
Dr. Riddell's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 8402024: 1,21945%
Drugs named by CMS: 25 in 2024, 20 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
Dr. Nathan E. Riddell ranks in the 91st percentile for leg revascularization (restoring blood flow) in Medicare
Dr. Riddell accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS counts 35 procedures of leg revascularization (restoring blood flow) by Dr. Riddell, more than 91% of the clinicians it reports for that procedure.
- Accepts Medicare assignment
- Yes
Where Dr. Riddell ranks in Medicare procedure volume
- Coronary angioplasty and stenting
- 77th percentile41 procedures
- Leg revascularization (restoring blood flow)
- 91st percentile35 procedures
CMS ranks each clinician against every clinician it reports for the same procedure category.
Pacemaker insertion or repair: 1 to 10 procedures (CMS shows small counts as a range)
Sources: Doctors and Clinicians National Downloadable File (CMS); and Doctors and Clinicians Utilization Data (CMS)
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Dr. Nathan E. Riddell received $6,636 in industry payments from 2019 to 2025
CMS Open Payments shows 92 general payments to Dr. Riddell from 25 drug and device companies from 2019 to 2025. Honoraria make up the largest share, 41% of the total. Abiomed paid the most, $2,750.
General payments to Dr. Riddell by program year, 2019 to 2025
General payments to Dr. Riddell by kind, 2019 to 2025
- Honoraria$2,75041%
- Food and beverage$2,41436%
- Travel and lodging$1,47322%
Companies that paid Dr. Riddell the most, 2019 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Dr. Nathan E. Riddell's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Nathan E. Riddell
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Nathan E. Riddell's NPI number?
Dr. Nathan E. Riddell's NPI number is 1245670983. It was assigned on June 26, 2013, and it is active in the NPI Registry.
What kind of doctor is Dr. Nathan E. Riddell?
Dr. Nathan E. Riddell is an internist in Lowell, Massachusetts. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Nathan E. Riddell practice?
Dr. Riddell practices at 295 Varnum Avenue, Lowell, MA 01854. Dr. Riddell's primary practice is Lowell General Hospital in Lowell, Massachusetts, part of Tufts Medicine. Dmand AI also links Dr. Riddell to 1 hospital, 3 medical groups and 1 group practice or clinic.
What is Dr. Nathan E. Riddell's office phone number?
The practice phone on file for Dr. Riddell is (978) 937-6000.
What is Dr. Nathan E. Riddell's medical license number?
Dr. Riddell holds Massachusetts license 256554.
Which hospitals is Dr. Nathan E. Riddell affiliated with?
Dr. Riddell practices at Lowell General Hospital in Lowell, Massachusetts. Dr. Riddell is also affiliated with UMass Memorial Medical Center - University Campus. Dmand AI links Dr. Riddell to 1 more hospital.
What medical group is Dr. Nathan E. Riddell part of?
Dr. Riddell is linked to Steward Medical Group. Dmand AI links Dr. Riddell to 3 more medical groups.
Does Dr. Nathan E. Riddell accept Medicare?
Yes. CMS data shows Dr. Riddell billed Medicare for 2,171 services in 2024, and Dr. Riddell accepts Medicare assignment.
How many Medicare patients does Dr. Nathan E. Riddell see?
CMS counts 1,464 Medicare patients who saw Dr. Riddell in 2024, with an average age of 76.
What services does Dr. Nathan E. Riddell bill to Medicare?
In 2024, Dr. Riddell's most billed Medicare services were heart test or procedure (93010), heart test or procedure (93306) and heart test or procedure (93000).
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What drugs does Dr. Nathan E. Riddell prescribe most?
In 2024 Medicare Part D data, Dr. Riddell's most prescribed drugs by claims were Metoprolol Succinate, Atorvastatin Calcium and Clopidogrel.
Has Dr. Nathan E. Riddell received payments from drug or device companies?
CMS Open Payments shows $6,636 in general payments to Dr. Riddell from 25 companies from 2019 to 2025. The largest total came from Abiomed.
How long has Dr. Nathan E. Riddell been practicing?
Dr. Riddell graduated from medical school in 2013, 13 years ago.
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