Wassim Assaf, MD
NPI 1548400278 · Sleep Medicine (Internal Medicine) Physician · Auburn, MA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Wassim Assaf, MD is a Sleep Medicine (Internal Medicine) Physician provider in Auburn, MA (NPI 1548400278).
Provider details
- NPI number
- 1548400278
- Entity type
- Individual
- Primary specialty
- Sleep Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 265574 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
17 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
4 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
753 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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 | 155 | $78 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 111 | $117 |
| Sleep Study Including Heart Rate, Breathing, and Sleep Time95800 | 76 | $70 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 74 | $67 |
| Sleep Study in Sleep Lab With Continuous Airway Pressure (6 Years Or Older)95811 | 64 | $336 |
| Sleep Study in Sleep Lab (6 Years Or Older) |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 9 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Cefpodoxime Proxetil | 26 | 26 |
| Prednisone | 17 | 17 |
| Gabapentin | 16 | — |
| Zolpidem Tartrate | 14 | 11 |
| Dextroamphetamine/Amphetaminebrand: Dextroamphetamine-Amphetamine | 13 | — |
| Pantoprazole Sodium | 13 | — |
| Clonazepam |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$56 across 2 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (3)
- 157 Union StMarlborough, MA 01752-1228Phone: (508) 486-5678Fax: (508) 486-5677
- 119 Belmont StWorcester, MA 01605-2903Phone: (508) 334-8515Fax: (508) 334-6490
- 55 Lake Ave NWorcester, MA 01655-0002Phone: (508) 334-8515Fax: (508) 334-6490
Registry dates
- Enumerated
- 2009-02-20
- Last updated
- 2021-02-03
- Certified
- 2021-02-03
Frequently asked questions
- What is Wassim Assaf's NPI number?
- Wassim Assaf's National Provider Identifier (NPI) is 1548400278, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Wassim Assaf's specialty?
- Wassim Assaf is listed in the NPPES registry with a primary specialty of Sleep Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Wassim Assaf located?
- Wassim Assaf's practice location on file with NPPES is 48 Auburn St Ste 1, Auburn, MA 01501-2438.
- What is Wassim Assaf's phone number?
- The practice phone number listed in the NPPES registry for Wassim Assaf is (774) 772-7058.
- Does Wassim Assaf accept Medicare?
- Wassim Assaf is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Wassim Assaf's NPI active?
- Yes — Wassim Assaf's NPI (1548400278) is active in the NPPES registry as of the last update on 2021-02-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.