William Slager
NPI 1902360605 · Physician Assistant · Grand Rapids, MI
Enrolled with Medicare as Practitioner - Physician Assistant · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Slager is a Physician Assistant provider in Grand Rapids, MI (NPI 1902360605).
Provider details
- NPI number
- 1902360605
- Entity type
- Individual
- Primary specialty
- Physician AssistantPhysician Assistants & Advanced Practice Nursing Providers
- Sex
- Male
- Sole proprietor
- No
- License
- 5601008991 (MI)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
7 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
43 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 25 | $117 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 18 | $79 |
Typical Medicare-allowed amounts for these services range $79–$117 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 33 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Erenumab-Aooebrand: Aimovig Autoinjector | 151 | 25 |
| Gabapentin | 99 | 23 |
| Dalfampridinebrand: Dalfampridine Er | 67 | — |
| Galcanezumab-Gnlmbrand: Emgality Pen | 63 | 11 |
| Fremanezumab-Vfrmbrand: Ajovy Autoinjector | 59 | 12 |
| Lamotrigine | 51 | 13 |
| Ubrogepantbrand: Ubrelvy | 48 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$46 across 1 record (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
Registry dates
- Enumerated
- 2019-01-27
- Last updated
- 2026-05-07
- Certified
- 2026-05-07
Frequently asked questions
- What is William Slager's NPI number?
- William Slager's National Provider Identifier (NPI) is 1902360605, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Slager's specialty?
- William Slager is listed in the NPPES registry with a primary specialty of Physician Assistant (Physician Assistants & Advanced Practice Nursing Providers).
- Where is William Slager located?
- William Slager's practice location on file with NPPES is 235 Wealthy St Se, Grand Rapids, MI 49503-5247.
- What is William Slager's phone number?
- The practice phone number listed in the NPPES registry for William Slager is (616) 840-8224.
- Does William Slager accept Medicare?
- William Slager is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Slager's NPI active?
- Yes — William Slager's NPI (1902360605) is active in the NPPES registry as of the last update on 2026-05-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.