DR. GREGORY MARK WITTENBURG (MD) – Family Medicine Physician, NPI 1689234916
Family Medicine Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
5,791 EMERGENCY MEDICINE in CA
Loading map...
Provider Addresses for DR. GREGORY MARK WITTENBURG (MD)
Contra Costa Regional Medical Center, 2500, Alhambra Avenue, Martinez, Contra Costa County, California, 94553, United States
MARTINEZ, CA 945533156
Phone: (925) 370-5000
Mailing address matches the actual address.
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: 2022-09-29
PECOS data refreshed: 2026-05-27
Medicare revalidation (CMS due date list)
Due date not assigned yet
CMS is tracking 2 Medicare enrollment records; no due dates published yet.
Enrollment records
2
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 |
|---|---|---|---|---|
| I20220526001114 | I | Emergency Medicine | CO | TBD |
| I20220929001773 | I | Emergency Medicine | KS | 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 |
|---|---|---|---|---|
| 99285 | Emergency department visit with high level of medical decision making | 111 | 107 | $0 |
| 99284 | Emergency department visit with moderate level of medical decision making | 70 | 68 | $0 |
| 93010 | Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only | 49 | 46 | $0 |
| 99291 | Critical care, first 30-74 minutes | 31 | 31 | $0 |
| 99232 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 25 | 12 | $0 |
Insurance plans in this area (ZIP 94553)
Loading plans...
Group practice members
| Name | Specialty | State |
|---|---|---|
| Emergency Medicine | CO | |
| Emergency Medicine | MI | |
| Emergency Medicine | CA | |
| - | OH | |
| Emergency Medicine | CO | |
| Emergency Medicine | CA | |
| Emergency Medicine | CO | |
| Emergency Medicine | CO | |
| Family Practice | KS | |
| - | OK |
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.