Robert Kalfus
Robert Kalfus is a Sleep Medicine (Internal Medicine) Physician in Chevy Chase, MD, registered under NPI 1750605200. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 5454 WISCONSIN AVE SUITE 1725, Chevy Chase, MD 20815. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| MD039449 | DC | Internal Medicine Physician |
| D007751 | MD | Sleep Medicine (Internal Medicine)… primary |
Licences are recorded in 2 states: DC, MD. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
Licensed in 2 states
This provider holds licences in 2 states: District of Columbia and Maryland. The practice address on file is in Chevy Chase, MD, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- MD039449
- Specialty
- Internal Medicine Physician
- Licence
- D007751
- Specialty
- Sleep Medicine (Internal Medicine)…
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Sleep Medicine covers
An Internist who practices Sleep Medicine is certified in the subspecialty of sleep medicine and specializes in the clinical assessment, physiologic testing, diagnosis, management and prevention of sleep and circadian rhythm disorders. Sleep specialists treat patients of any age and use multidisciplinary approaches. Disorders managed by sleep specialists include, but are not limited to, sleep related breathing disorders, insomnia, hypersomnias, circadian rhythm sleep disorders, parasomnias and sleep related movement disorders. NUCC Health Care Provider Taxonomy, code 207RS0012X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207R00000X | Internal Medicine Physician | MD039449 | DC | |
| 207RS0012X | Sleep Medicine (Internal Medicine) Physician Sleep Medicine | D007751 | MD | primary |
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.
| NPI | 1750605200 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 25, 2010 |
| Last updated | Jul 1, 2014 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Practice address |
5454 WISCONSIN AVE SUITE 1725 Chevy Chase, MD 20815 (301) 654-1575 Fax (301) 654-5658 |
Number check
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 | 7 | 5 | 0 | 6 | 0 | 5 | 2 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 7 | 1 | 0 | 3 | 0 | 1 | 2 | 0 |
Sum = 40 · next multiple of 10 = 40 · check digit = 0 · actual last digit = 0
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.