MARK H JOHNSTON MD
NPI 1003898131
Internal Medicine - Gastroenterology in Lancaster, PA

Q: What is Mark Johnston's NPI number?

The NPI number for Mark Johnston is 1003898131. It was assigned to this individual provider in the NPPES registry on November 15, 2005.

Q: What is Mark Johnston's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Q: When was this NPI record last updated?

The NPPES record for Mark Johnston was last updated on June 13, 2019. NPI Profile syncs with the weekly NPPES data releases published by CMS.

Active since November 15, 2005PECOS EnrolledAccepts Medicare Assignment

2112 HARRISBURG PIKE, SUITE 202, LANCASTER, PA 17601(717) 544-3500(717) 544-3501 Get Directions Write a Review

NPPES record last updated: June 13, 2019. Verified against the NPPES registry weekly; last sync: July 26, 2026.

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About Mark H Johnston Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MARK H JOHNSTON MD (NPI 1003898131) is an individual gastroenterology provider in Lancaster, Pennsylvania, licensed in Pennsylvania (MD425522) and active in the NPI registry since November 2005. He is enrolled in Medicare PECOS, is affiliated with Lancaster General Hospital, and is a graduate of Hahnemann University College Of Medicine (1985).

NPPES Registry Identity

NPI1003898131

Entity TypeIndividualMale

Primary Taxonomy207RG0100X

Provider Legal NameMARK H JOHNSTONCredential: MD

Location Address2112 HARRISBURG PIKE, SUITE 202Lancaster, PA 17601-2644

Mailing Address2112 Harrisburg Pike Ste 202Lancaster, PA 17601-2644 · (717) 869-4600 · Fax (717) 544-3501

Phone(717) 544-3500

Fax(717) 544-3501

Sole ProprietorNo

Medical School CMSHahnemann University College Of MedicineGraduated 1985

Enumeration DateNovember 15, 2005

Last NPPES UpdateJune 13, 2019

✔ NPI 1003898131 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians

Taxonomy Code207RG0100X

License✔ Licensed in PA · MD425522

Definition

An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.

2112 HARRISBURG PIKE, Lancaster, PA 17601

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Other Identifiers 5

Medicaid1012082120004PA

OtherP01832235PA · Rr Medicare

Medicaid1012082120002PA

Other093677KKUPA · Medicare

Medicaid1012082120005PA

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Buckeye Health Plan, Ambetter Health, Ambetter Health of Delaware.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Mark H Johnston Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID7618908500

PECOS Enrollment IDI20050831000030

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 13

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Injection, infliximab, excludes biosimilar, 10 mg J1745

Infliximab is a medication given via injection to treat certain autoimmune conditions. It works by blocking the action of a substance in your body that causes inflammation. Each dose is based on your medical condition and response to treatment.

1,130 services11 patients

Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385

This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.

102 services100 patients

Biopsy of large bowel using a flexible endoscope 45380

A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.

99 services99 patients

Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239

This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.

71 services69 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

46 services41 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

42 services33 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

27 services26 patients

Colorectal cancer screening; colonoscopy on individual at high risk G0105

Colorectal cancer screening, specifically a colonoscopy, is a preventive measure for those at high risk. A thin, flexible tube with a camera inspects the colon to spot any abnormal growths. This test helps detect potential issues early, enhancing the effectiveness of treatment.

22 services22 patients

Balloon dilation of esophagus, stomach, and/or upper small bowel using a flexible endoscope, less than 3.0 cm 43249

This procedure involves using a flexible tube with a camera, called an endoscope, to gently expand narrowed areas in your esophagus, stomach, or upper small bowel. A small balloon is inflated, making it easier for food and liquid to pass through. It's safe and effective.

21 services14 patients

Dilation of esophagus 43450

Dilation of the esophagus is a procedure aimed to stretch or open up your esophagus (the tube connecting your mouth to your stomach) when it's narrow. It helps to improve swallowing and alleviate discomfort. It's typically performed using a flexible tube or balloon, under sedation.

19 services19 patients

Administration of chemotherapy into vein, 1 hour or less 96413

Chemotherapy is a treatment that uses drugs to destroy cancer cells. When administered into a vein, it's often through an IV. This procedure usually lasts 1 hour or less. You may feel a slight pinch as the needle is inserted, but it's generally painless.

16 services11 patients

Administration of chemotherapy into vein, each additional hour 96415

Chemotherapy is a treatment method that uses drugs to destroy cancer cells. The drugs are administered into a vein, usually in the arm. Each additional hour of chemotherapy allows for more of the medication to enter your bloodstream to fight against the cancer cells.

16 services11 patients

Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk G0121

Colorectal cancer screening, such as a colonoscopy, is a preventive measure to detect early signs of cancer in the large intestine. For individuals not at high risk, it's typically recommended at age 50. A small, flexible tube with a camera is used to examine your colon. It's a safe, effective way to catch issues early.

16 services16 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Lancaster General Hospital

Acute Care Hospitals · Lancaster, PA

5/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number390100

Location555 North Duke StreetLancaster, PA 17602 · Lancaster County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 17601 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$126.34 typical visit price

range $54.64 – $166.87

Typical copayment $31.58 (range $13.66 – $41.71)

Most-billed visit code 99204

Established Patient

$96.82 typical visit price

range $17.33 – $135.84

Typical copayment $24.20 (range $4.33 – $33.96)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

FOTINI DEBONERA MD

Family Medicine

2112 HARRISBURG PIKE, SUITE 312
LANCASTER, PA 17601

Lancaster County (717) 544-3022

CHARLES R ROST M.D.

Internal Medicine (Endocrinology, Diabetes & Metabolism)

2112 HARRISBURG PIKE, SUITE 200
LANCASTER, PA 17601

Lancaster County (717) 544-3059

ALYSSA R SOBIERAY RD

Dietitian, Registered

2112 HARRISBURG PIKE, SUITE 312
LANCASTER, PA 17601

Lancaster County (717) 291-8399

DR. PAUL DAVID ALLEGRETTI D.O.

Internal Medicine (Gastroenterology)

2112 HARRISBURG PIKE, SUITE 202
LANCASTER, PA 17601

Lancaster County (717) 544-3500

STEVE T CHEN M.D.

Internal Medicine (Gastroenterology)

2112 HARRISBURG PIKE, STE 202
LANCASTER, PA 17601

Lancaster County (717) 544-3500

ANNA KWAKYE ANTWI CRNP

Nurse Practitioner (Family)

2112 HARRISBURG PIKE, STE 200
LANCASTER, PA 17601

Lancaster County (717) 544-3059

HEATHER M FRIED CRNP

Nurse Practitioner (Family)

2112 HARRISBURG PIKE
LANCASTER, PA 17601

Lancaster County (717) 544-3022

MATTHEW SAUDER M.D.

Internal Medicine (Endocrinology, Diabetes & Metabolism)

2112 HARRISBURG PIKE, STE 200
LANCASTER, PA 17601

Lancaster County (717) 544-3059

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mark Johnston's NPI number?

The NPI number for Mark Johnston is 1003898131. It was assigned to this individual provider in the NPPES registry on November 15, 2005.

Where is Mark Johnston located?

Mark Johnston practices at 2112 Harrisburg Pike Suite 202, Lancaster, PA 17601. The listed phone number is (717) 544-3500.

What is Mark Johnston's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Mark Johnston enrolled in Medicare?

Yes. Mark Johnston is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

What insurance does Mark Johnston accept?

Health plans from Ambetter Health, Ambetter Health of Delaware and Ambetter from Buckeye Health Plan list Mark Johnston as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Mark Johnston affiliated with any hospitals?

According to CMS data, Mark Johnston is affiliated with Lancaster General Hospital.

When was this NPI record last updated?

The NPPES record for Mark Johnston was last updated on June 13, 2019. NPI Profile syncs with the weekly NPPES data releases published by CMS.