MARK T FAHLEN (MD) – Nephrology Physician, NPI 1679539415
Nephrology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
1,404 NEPHROLOGY in CA
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Provider Addresses for MARK T FAHLEN (MD)
1400, Florida Avenue, Aurora, Modesto, Stanislaus County, California, 95350, United States
SUITE 109
MODESTO, CA 953504422
Phone: (209) 544-2910
Mailing address matches the actual address.
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 1 Open Payments records for all available years, with a total value of $32.
Total Amount is formed as General ($32) + Research ($0) + Ownership ($0) = $32.
Last reported payment date: 2023-05-04 • Largest payer in this snapshot: NxStage Medical, Inc. ($32).
Total Amount
$32
General + Research + Ownership
Payments
1
Total payment records
General Amount
$32
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2023-05-04
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| NxStage Medical, Inc. | $32 |
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: 2004-09-08
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 |
|---|---|---|---|---|
| I20040908000652 | I | Nephrology | CA | 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 |
|---|---|---|---|---|
| 90962 | Dialysis services, 1 physician visit per month (20 years or older) | 680 | 101 | $0 |
| 99214 | Established patient office or other outpatient visit, 30-39 minutes | 604 | 235 | $0 |
| 90935 | Hemodialysis procedure with physician evaluation | 344 | 89 | $0 |
| 99232 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 277 | 105 | $0 |
| 90966 | Home dialysis services per month (20 years or older) | 76 | 11 | $0 |
Insurance plans in this area (ZIP 95350)
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Provider's Procedures
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