Mary Callsen
NPI 1639137573 · Internal Medicine Physician · Bethesda, MD
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Callsen is a Internal Medicine Physician provider in Bethesda, MD (NPI 1639137573).
Provider details
- NPI number
- 1639137573
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Sex
- Female
- Sole proprietor
- No
- License
- D0059499 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
1,852 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 447 | $108 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 387 | $142 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 353 | $89 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 158 | $9 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 110 | $133 |
| Admn Sarscov2 Vacc 1 Dose90480 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 65 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 600 | 179 |
| Amlodipine Besylate | 242 | 73 |
| Losartan Potassium | 221 | 69 |
| Levothyroxine Sodium | 206 | 65 |
| Hydrochlorothiazide | 189 | 56 |
| Rosuvastatin Calcium | 179 | 56 |
| Metformin Hcl |
Practice location
Mailing address
Additional practice locations (1)
- 7513 Wisconsin AveSuite 645Chevy Chase, MD 20815-4404Phone: (301) 656-4545
Registry dates
- Enumerated
- 2006-05-02
- Last updated
- 2023-01-27
- Certified
- 2023-01-27
Frequently asked questions
- What is Mary Callsen's NPI number?
- Mary Callsen's National Provider Identifier (NPI) is 1639137573, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Callsen's specialty?
- Mary Callsen is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mary Callsen located?
- Mary Callsen's practice location on file with NPPES is 7315 Wisconsin Ave, Bethesda, MD 20814-3202.
- What is Mary Callsen's phone number?
- The practice phone number listed in the NPPES registry for Mary Callsen is (240) 235-9100.
- Does Mary Callsen accept Medicare?
- Mary Callsen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Callsen's NPI active?
- Yes — Mary Callsen's NPI (1639137573) is active in the NPPES registry as of the last update on 2023-01-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.