Individual provider

Ronald Zimmermann, D.O.

Hospitalist Physician Internal Medicine Physician Medicare enrolled

Ronald Zimmermann, D.O. is a Hospitalist Physician in Naperville, IL, registered under NPI 1346404985. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.

Getting there

The practice address on file is 801 S WASHINGTON ST, Naperville, IL 60540. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.

801 S WASHINGTON ST, Naperville, IL 60540 Open in Google Maps →

Credentials and Medicare

State licence
LicenceStateSpecialty
036.128777 IL Hospitalist Physician primary
125054800 IL Internal Medicine Physician
036128777 IL Internal Medicine Physician

This provider holds licence 036.128777 issued in IL. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.

Medicare (PECOS)
Status
Approved
Provider type
Practitioner - Internal Medicine
PAC ID
5991976300

Medicare enrolment is recorded as approved under the provider type Practitioner - Internal Medicine. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.

What Hospitalist covers

Hospitalists are physicians whose primary professional focus is the general medical care of hospitalized patients. Their activities include patient care, teaching, research, and leadership related to Hospital Medicine. The term 'hospitalist' refers to physicians whose practice emphasizes providing care for hospitalized patients. NUCC Health Care Provider Taxonomy, code 208M00000X
Allopathic & Osteopathic Physicians Hospitalist

All registered taxonomy codes

This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.

CodeSpecialtyLicenceState
208M00000X Hospitalist Physician 036.128777 IL primary
207R00000X Internal Medicine Physician 125054800 IL
207R00000X Internal Medicine Physician 036128777 IL

The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.

Full NPPES record

An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.

NPI1346404985 valid check digit
Entity typeIndividual (NPI-1)
Enumeration dateJul 14, 2008
Last updatedDec 10, 2021
StatusActive
Sole proprietorNo
CredentialD.O.
Practice address 801 S WASHINGTON ST
Naperville, IL 60540
(630) 646-8704
Mailing address 1319 WINGFIELD WAY
Bolingbrook, IL 60490
The last update on file is Dec 10, 2021. Providers are only required to update NPPES when their information changes, so an older date does not necessarily mean the details are wrong — but it is worth a quick call before you travel.

Number check

1346404985 passes the NPI check digit test The final digit 5 matches the value computed from the first nine digits, so this is a well-formed NPI.
How the check works, step by step

Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.

Digit 8 0 8 4 0 1 3 4 6 4 0 4 9 8
Doubled? ×2 ×2 ×2 ×2 ×2 ×2 ×2
Value 8 0 8 8 0 2 3 8 6 8 0 8 9 7

Sum = 75 · next multiple of 10 = 80 · check digit = 5 · actual last digit = 5

A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.

Common questions

What is NPI number 1346404985?
NPI 1346404985 is the National Provider Identifier assigned to Ronald Zimmermann, D.O. in Naperville, IL. It is a 10-digit number issued by the Centers for Medicare & Medicaid Services and used on claims, referrals, and prescriptions to identify the provider.
What does Hospitalist Physician cover?
Hospitalists are physicians whose primary professional focus is the general medical care of hospitalized patients. Their activities include patient care, teaching, research, and leadership related to Hospital Medicine. The term 'hospitalist' refers to physicians whose practice emphasizes providing care for…
How do I contact Ronald Zimmermann, D.O.?
The phone number on file with NPPES is (630) 646-8704, last updated Dec 10, 2021. Because NPPES is only updated when a provider files a change, call ahead to confirm the number and the current practice address before visiting.
Does Ronald Zimmermann, D.O. accept Medicare?
This NPI has an approved Medicare enrolment in PECOS, which means the provider is enrolled to bill Medicare. Enrolment does not guarantee they are accepting new Medicare patients — verify directly with the office.
Is NPI 1346404985 a valid number?
Yes. 1346404985 passes the Luhn check digit validation that CMS uses for NPI numbers, and it resolves to an active record in the registry.
How to use this page. Everything here comes from public federal records. Tips Health does not verify quality of care, confirm that a licence is currently active, or check malpractice history, and accepts no fees for placement. A listing is not a recommendation. Verify independently before seeking care.