WILLIAM G GREHAN (MD) – Anesthesiology Physician, NPI 1417961061
Anesthesiology Physician
Main info
Doctor Profile
Contacts
Profile Insights
NPPES metrics only — not quality of care.
2,631 ANESTHESIOLOGY in IL
Provider Addresses for WILLIAM G GREHAN (MD)
4440 W 95th St
Oak Lawn, IL 604532600
Phone: (708) 684-8000
Type: Location
Lake Cook Road, Deerfield, Northfield Township, Cook County, Illinois, 60015, United States
STE M
DEERFIELD, IL 600155234
Phone: (847) 945-4550
Fax: (847) 948-8103
Type: Mailing
North Avenue, Melrose, Middlesex County, Massachusetts, 01180, United States
MELROSE PARK, IL 601601612
Phone: (708) 681-3202
Type: Location
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
Loading prescription activity...
Open Payments (CMS)
No Open Payments data available for this provider.
This can happen when there are no reportable CMS Open Payments records.
Medicare Enrollment & Revalidation
Source: CMS public data · Not endorsed by CMS ·
Educational use only—not medical, billing, or legal advice.
PECOS enrollment status
Participating (accepts Medicare assignment)
Enrollment effective: 2025-12-04
PECOS data refreshed: 2026-05-27
Medicare revalidation (CMS due date list)
Due date not assigned yet
CMS is tracking 3 Medicare enrollment records; no due dates published yet.
Enrollment records
3
Earliest due date
Not assigned (TBD)
CMS data updated
2026-06-01
Revalidation progress
- Medicare enrolled
- On CMS revalidation list
- Due date assigned
- Revalidate in PECOS
CMS enrollment records
| Enrollment ID | Type | Specialty | State | Due date |
|---|---|---|---|---|
| I20040127000073 | I | Anesthesiology | IL | TBD |
| I20230912004161 | I | Anesthesiology | SC | TBD |
| I20251204004745 | I | Anesthesiology | SD | TBD |
What to do next
- No action required while the due date shows TBD.
- Check the CMS Revalidation Lookup Tool periodically — CMS updates the list about every 60 days.
- Do not submit a revalidation application in PECOS until CMS publishes a concrete due date.
Prepare CMS-855 application → · Look up this NPI in PECOS → · Verify on CMS PECOS
Medicare Utilization (FFS)
Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·
Educational use only—not medical, billing, or legal advice.
Top Medicare procedures (2023) · refreshed 2026-05-27
| HCPCS | Description | Services | Beneficiaries | Medicare allowed |
|---|---|---|---|---|
| 00142 | Anesthesia for lens surgery | 83 | 82 | $0 |
| 01402 | Anesthesia for procedure for total knee joint replacement | 66 | 66 | $0 |
| 64447 | Injection of anesthetic agent and/or steroid into thigh nerve (femoral nerve) | 48 | 47 | $0 |
| 01214 | Anesthesia for total hip replacement | 42 | 42 | $0 |
| 64415 | Injection of anesthetic agent and/or steroid into arm nerve bundle (brachial plexus) | 31 | 31 | $0 |
Insurance plans in this area (ZIP 60453)
Loading plans...
Provider's Procedures
| Specialty | Practice State | HCPCS Code | Description | Service Count | Beneficiary Count |
|---|---|---|---|---|---|
| ANESTHESIOLOGY | IL | 01402 | Anesthesia for open or endoscopic total knee joint replacement | 25 | 25 |
Group practice members
| Name | Specialty | State |
|---|---|---|
| Anesthesiology Assistant | MO | |
| Certified Registered Nurse Anesthetist (Crna) | MO | |
| Anesthesiology Assistant | NC | |
| A N E S T H E S I O L O G Y | MO | |
| Certified Registered Nurse Anesthetist (Crna) | MO | |
| Certified Registered Nurse Anesthetist (Crna) | MO | |
| Certified Registered Nurse Anesthetist (Crna) | MO | |
| Certified Registered Nurse Anesthetist (Crna) | IL | |
| Anesthesiology, Critical Care (Intensivists) | MO | |
| Certified Registered Nurse Anesthetist (Crna) | IL |
Reviews
All reviews are moderated before publication. Reviews reflect users' opinions; we do not verify the accuracy of individual reviews.
No reviews yet. Be the first to share your experience — your opinion helps families compare providers.