Gretchen Diemer, M.D.
NPI 1164457289 · Internal Medicine Physician · Philadelphia, PA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gretchen Diemer, M.D. is a Internal Medicine Physician provider in Philadelphia, PA (NPI 1164457289).
Provider details
- NPI number
- 1164457289
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Female
- Sole proprietor
- No
- License
- MD424123 (PA)
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
19 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
169 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 98 | $80 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 42 | $119 |
| Hospital Discharge Day Management, 30 Minutes Or Less99238 | 15 | $82 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 14 | $175 |
Typical Medicare-allowed amounts for these services range $80–$175 (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
Additional practice locations (1)
- 833 Chestnut StSuite 701Philadelphia, PA 19107-4409Phone: (215) 955-6180Fax: (215) 955-6410
Registry dates
- Enumerated
- 2006-07-11
- Last updated
- 2025-03-13
- Certified
- 2025-03-13
Frequently asked questions
- What is Gretchen Diemer's NPI number?
- Gretchen Diemer's National Provider Identifier (NPI) is 1164457289, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gretchen Diemer's specialty?
- Gretchen Diemer is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Gretchen Diemer located?
- Gretchen Diemer's practice location on file with NPPES is 3401 N Broad St, Philadelphia, PA 19140-5103.
- What is Gretchen Diemer's phone number?
- The practice phone number listed in the NPPES registry for Gretchen Diemer is (215) 707-3807.
- Does Gretchen Diemer accept Medicare?
- Gretchen Diemer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gretchen Diemer's NPI active?
- Yes — Gretchen Diemer's NPI (1164457289) is active in the NPPES registry as of the last update on 2025-03-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.