MARK H JOHNSTON (MD) – Gastroenterology Physician, NPI 1003898131
Gastroenterology Physician
Main info
Doctor Profile
Profile Insights
NPPES metrics only — not quality of care.
1,182 GASTROENTEROLOGY in PA
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Provider Addresses for MARK H JOHNSTON (MD)
202, Harrisburg Avenue, Lancaster, Lancaster County, Pennsylvania, 17603, United States
LANCASTER, PA 176012644
Phone: (717) 869-4600
Fax: (717) 544-3501
Type: Mailing
LG Health Physicians Geriatrics, 2112, Harrisburg Pike, McGovernsville, Rohrerstown, Lancaster County, Pennsylvania, 17601, United States
SUITE 202
LANCASTER, PA 176012644
Phone: (717) 544-3500
Fax: (717) 544-3501
Type: Location
NPPES updates history
No NPPES updates recorded for this provider.
Prescription Activity
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Open Payments (CMS)
CMS reports 74 Open Payments records for all available years, with a total value of $1,512.
Total Amount is formed as General ($1,512) + Research ($0) + Ownership ($0) = $1,512.
Last reported payment date: 2024-12-09 • Largest payer in this snapshot: ABBVIE INC. ($718).
Total Amount
$1,512
General + Research + Ownership
Payments
74
Total payment records
General Amount
$1,512
General payments
Research Amount
$0
Research funding
Ownership Amount
$0
Ownership interests
Ownership Count
0
Ownership records
Last Payment Date
2024-12-09
Latest reported date
Top Companies
Largest payers in this snapshot
| Company | Amount |
|---|---|
| ABBVIE INC. | $718 |
| GENZYME CORPORATION | $143 |
| Celgene Corporation | $140 |
| PFIZER INC. | $93 |
| Takeda Pharmaceuticals U.S.A., Inc. | $78 |
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: 2005-08-31
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 |
|---|---|---|---|---|
| I20050831000030 | I | Gastroenterology | PA | 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 |
|---|---|---|---|---|
| J3380 | Injection, vedolizumab, 1 mg | 4,500 | 11 | $0 |
| J1745 | Injection, infliximab, excludes biosimilar, 10 mg | 1,400 | 14 | $0 |
| 45380 | Biopsy of large bowel using a flexible endoscope | 117 | 117 | $0 |
| 99213 | Established patient office or other outpatient visit, 20-29 minutes | 87 | 76 | $0 |
| 99214 | Established patient office or other outpatient visit, 30-39 minutes | 85 | 76 | $0 |
Insurance plans in this area (ZIP 17601)
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Provider's Procedures
| Specialty | Practice State | HCPCS Code | Description | Service Count | Beneficiary Count |
|---|---|---|---|---|---|
| GASTROENTEROLOGY | PA | 43235 | Diagnostic examination of esophagus, stomach, and/or upper small bowel using an endoscope | 21 | 21 |
| GASTROENTEROLOGY | PA | 45378 | Diagnostic examination of large bowel using an endoscope | 13 | 13 |
| GASTROENTEROLOGY | PA | 45385 | Removal of polyps or growths of large bowel using an endoscope | 66 | 64 |
Group practice members
| Name | Specialty | State |
|---|---|---|
| G A S T R O E N T E R O L O G Y | PA | |
| G A S T R O E N T E R O L O G Y | IL | |
| G A S T R O E N T E R O L O G Y | PA | |
| G A S T R O E N T E R O L O G Y | PA | |
| - | PA | |
| Physician Assistant | MD | |
| G A S T R O E N T E R O L O G Y | PA | |
| G A S T R O E N T E R O L O G Y | PA | |
| Physician Assistant | PA | |
| Physician Assistant | PA |
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