Mark Nau, M.D.
NPI 1033579479 · Critical Care Medicine (Internal Medicine) Physician · Fort Belvoir, VA
Enrolled with Medicare as Practitioner - Critical Care (intensivists) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Nau, M.D. is a Critical Care Medicine (Internal Medicine) Physician provider in Fort Belvoir, VA (NPI 1033579479).
Provider details
- NPI number
- 1033579479
- Entity type
- Individual
- Primary specialty
- Critical Care Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- D0093781 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
10 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
19 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Critical Care, First 30-74 Minutes99291 | 19 | $218 |
Typical Medicare-allowed amounts for these services range $218–$218 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2016-02-27
- Last updated
- 2025-05-19
- Certified
- 2025-05-19
Frequently asked questions
- What is Mark Nau's NPI number?
- Mark Nau's National Provider Identifier (NPI) is 1033579479, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Nau's specialty?
- Mark Nau is listed in the NPPES registry with a primary specialty of Critical Care Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Nau located?
- Mark Nau's practice location on file with NPPES is 9300 Dewitt Loop, Fort Belvoir, VA 22060-5285.
- What is Mark Nau's phone number?
- The practice phone number listed in the NPPES registry for Mark Nau is (571) 231-1605.
- Does Mark Nau accept Medicare?
- Mark Nau is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Nau's NPI active?
- Yes — Mark Nau's NPI (1033579479) is active in the NPPES registry as of the last update on 2025-05-19.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.