Mark Siedner, MD
NPI 1548429178 · Infectious Disease Physician · Boston, MA
Enrolled with Medicare as Practitioner - Infectious Disease · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Siedner, MD is a Infectious Disease Physician provider in Boston, MA (NPI 1548429178).
Provider details
- NPI number
- 1548429178
- Entity type
- Individual
- Primary specialty
- Infectious Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 253779 (MA)
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
18 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
178 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 | 100 | $82 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 34 | $180 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 25 | $123 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 19 | $137 |
Typical Medicare-allowed amounts for these services range $82–$180 (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
- 2008-06-09
- Last updated
- 2012-12-08
Frequently asked questions
- What is Mark Siedner's NPI number?
- Mark Siedner's National Provider Identifier (NPI) is 1548429178, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Siedner's specialty?
- Mark Siedner is listed in the NPPES registry with a primary specialty of Infectious Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Siedner located?
- Mark Siedner's practice location on file with NPPES is 55 Fruit St, Boston, MA 02114-2621.
- What is Mark Siedner's phone number?
- The practice phone number listed in the NPPES registry for Mark Siedner is (617) 726-3812.
- Does Mark Siedner accept Medicare?
- Mark Siedner is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Siedner's NPI active?
- Yes — Mark Siedner's NPI (1548429178) is active in the NPPES registry as of the last update on 2012-12-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.