BARBARA DIAKOS (MD) – Obstetrics & Gynecology Physician, NPI 1912934423
Obstetrics & Gynecology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
966 OBSTETRICS/GYNECOLOGY in IN
Provider Addresses for BARBARA DIAKOS (MD)
8558 BROADWAY
MERRILLVILLE, IN 464107032
Phone: (219) 739-2770
Fax: (219) 703-6854
Type: Mailing
9660 WICKER AVE FL 2
SAINT JOHN, IN 463739487
Phone: (219) 226-2236
Type: Location
British School of Chicago, 1460, North Halsted Street, Chicago River North, Lincoln Park, Chicago, Cook County, Illinois, 60642, United States
SUITE 503
CHICAGO, IL 606422605
Phone: (773) 472-1444
Fax: (312) 787-4424
Type: Mailing
9660 WICKER AVE
SAINT JOHN, IN 463739487
Phone: (219) 226-2236
Type: Location
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 20 Open Payments records for all available years, with a total value of $324.
Total Amount is formed as General ($324) + Research ($0) + Ownership ($0) = $324.
Last reported payment date: 2024-12-12 • Largest payer in this snapshot: Organon LLC ($83).
Total Amount
$324
General + Research + Ownership
Payments
20
Total payment records
General Amount
$324
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2024-12-12
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| Organon LLC | $83 |
| Astellas Pharma US Inc | $58 |
| Bayer Healthcare Pharmaceuticals Inc. | $55 |
| MAYNE PHARMA COMMERCIAL LLC | $34 |
| ABBVIE INC. | $33 |
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: 2019-08-22
PECOS data refreshed: 2026-05-27
Medicare revalidation (CMS due date list)
Due date not assigned yet
CMS is tracking this Medicare enrollment for revalidation, but has not published a due date.
Enrollment records
1
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 |
|---|---|---|---|---|
| I20190822001371 | I | Obstetrics/Gynecology | IN | 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 |
|---|---|---|---|---|
| G0101 | Cervical or vaginal cancer screening; pelvic and clinical breast examination | 36 | 36 | $0 |
| 99203 | New patient office or other outpatient visit, 30-44 minutes | 26 | 26 | $0 |
| 99213 | Established patient office or other outpatient visit, 20-29 minutes | 17 | 12 | $0 |
Insurance plans in this area (ZIP 46410)
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Group practice members
| Name | Specialty | State |
|---|---|---|
| E N D O C R I N O L O G Y | IN | |
| - | IL | |
| Nurse Practitioner | IN | |
| Nurse Practitioner | IN | |
| N E U R O L O G Y | NE | |
| Nurse Practitioner | IL | |
| Internal Medicine | IN | |
| O B S T E T R I C S/ G Y N E C O L O G Y | IL | |
| R H E U M A T O L O G Y | IN | |
| Internal Medicine | IL |
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