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DAVID W. KOSSOFF, M.D., LLC
NPI 1437206984
Specialist in Frederick, MD

Active since January 05, 2007CLIA 21D1037930 · Waiver
110 THOMAS JOHNSON DR STE 335, FREDERICK, MD 21702(301) 624-5566(301) 624-5542 Get Directions Write a Review

NPPES record last updated: May 19, 2025. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: May 19, 2025, Mar 11, 2022 (2 updates tracked since 2022).

About David W. Kossoff, M.d., Llc NPPES

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

DAVID W. KOSSOFF, M.D., LLC (NPI 1437206984), doing business as Optimal Digestive Care, is a healthcare organization registered as a specialist in Frederick, Maryland and active in the NPI registry since January 2007. The organization holds a CLIA Waiver certificate valid through March 7, 2027 and lists Alan Oliver, Ceo, as its authorized official.

NPPES Registry Identity

NPI1437206984
Entity TypeOrganization
Primary Taxonomy174400000X
Legal Business NameDAVID W. KOSSOFF, M.D., LLC
Location Address110 THOMAS JOHNSON DR STE 335Frederick, MD 21702-4949
Mailing Address110 Thomas Johnson Dr Ste 335Frederick, MD 21702-4949 · (301) 624-5566 · Fax (301) 624-5542
Phone(301) 624-5566
Fax(301) 624-5542
Organization SubpartNo
Authorized OfficialAlan OliverCeo · (786) 530-3820
Enumeration DateJanuary 5, 2007
Last NPPES UpdateMay 19, 20252 updates tracked since enumeration
NPPES CertifiedMay 19, 2025
✔ NPI 1437206984 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers
Taxonomy Code174400000X
License✔ Licensed in MD · D0054121
Definition
An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.
110 THOMAS JOHNSON DR STE 335, Frederick, MD 21702
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Other Names 1

Doing Business AsOptimal Digestive Care

Other Identifiers 7

Other682BDAMD · Carefrist Of Md
Other376329MD · Mdipa Opt Choice
OtherP10152MD · Informed
Other4040001MD · Carefirst Nat Cap Area
OtherP00206418MD · Railroad Medicare
Medicaid133102701MD
Other494710MD · Ncppo

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

David W. Kossoff, M.d., Llc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

11

Medicare enrollment records show 11 clinicians reassign Medicare billing to David W. Kossoff, M.D., LLC, which bills Medicare for the services they deliver. Of these, 4 practice at this address and 6 within 10 miles. They are listed nearest first.

Clinicians by Medicare Specialty 2

Nurse Practitioner6
Gastroenterology5

Clinicians, nearest first (11)

Lindsay Bitto
Nurse Practitioner
NPI 1972904845
110 THOMAS JOHNSON DR STE 335
Frederick, MD 21702
(301) 624-5566
✔ PECOS✔ Accepts MedicareSame address
Pilin Francis, DO
Gastroenterology
NPI 1669967592
110 THOMAS JOHNSON DR STE 335
Frederick, MD 21702
(301) 624-5566
✔ PECOS✔ Accepts MedicareSame address
David Kossoff, M.D.
Gastroenterology
NPI 1629152582
110 THOMAS JOHNSON DR STE 335
Frederick, MD 21702
(301) 624-5566
✔ PECOS✔ Accepts MedicareSame address
Arash Zarrin, DO
Gastroenterology
NPI 1407351729
110 THOMAS JOHNSON DR STE 335
Frederick, MD 21702
(301) 624-5566
✔ PECOS✔ Accepts MedicareSame address
Heather Hayes, NP
Nurse Practitioner
NPI 1891330908
194 THOMAS JOHNSON DR
Frederick, MD 21702
(240) 215-6310
✔ PECOS✔ Accepts Medicare0.4 mi
Hemant Chatrath, M.D.
Gastroenterology
NPI 1639306012
400 W 7TH ST
Frederick, MD 21701
(240) 215-6310
✔ PECOS✔ Accepts Medicare1.7 mi
Erin Oman, CRNP
Nurse Practitioner
NPI 1891260741
11110 MEDICAL CAMPUS RD STE 246
Hagerstown, MD 21742
(301) 665-4585
✔ PECOS✔ Accepts Medicare19 mi
Sarah Knowlton, FNP
Nurse Practitioner
NPI 1558716852
911 MEETING ST
North Bethesda, MD 20852
(888) 663-6331
✔ PECOS✔ Accepts Medicare31 mi
Kathleen Lawson, FNP-C
Nurse Practitioner
NPI 1174396121
106 IRVING ST NW
Washington, DC 20010
(202) 877-7108
✔ PECOS✔ Accepts Medicare41 mi
Brendon Bower
Nurse Practitioner
NPI 1972070316
228 PARK AVE S STE 16389
New York, NY 10003
(646) 876-8455
✔ PECOS202 mi
Kaio Ferreira, MD
Gastroenterology
NPI 1689103293
5701 W CHARLESTON BLVD STE 201
Las Vegas, NV 89146
(702) 750-0313
✔ PECOS✔ Accepts Medicare2,067 mi

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

CLIA Laboratory Certificates CMS CLIA

Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.

Certificate of Waiver 21D1037930

David W Kossoff MD PA Dba Optimal Digestive Care · Frederick, MD
Active · expires Mar 7, 2027
CLIA Number21D1037930
Laboratory TypePhysician Office
Certificate Effective DateMarch 8, 2025
Certificate Expiration DateMarch 7, 2027
Laboratory DirectorDavid W. Kossoff
Laboratory Phone(301) 624-5566
Laboratory LocationDavid W Kossoff MD PA Dba Optimal Digestive Care110 Thomas Johnson Dr Ste 335, Frederick, MD 21702
CLIA data matches this NPI record on: Address Name Phone
This certificate is issued to a laboratory to perform only waived tests.

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 David W. Kossoff, M.D., LLC's NPI number?

The NPI number for David W. Kossoff, M.D., LLC is 1437206984. It was assigned to this organization in the NPPES registry on January 5, 2007. The provider is doing business as Optimal Digestive Care.

Where is David W. Kossoff, M.D., LLC located?

David W. Kossoff, M.D., LLC is located at 110 Thomas Johnson Dr Ste 335, Frederick, MD 21702. The listed phone number is (301) 624-5566.

What is David W. Kossoff, M.D., LLC's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Is David W. Kossoff, M.D., LLC enrolled in Medicare?

Yes. David W. Kossoff, M.D., LLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through David W. Kossoff, M.D., LLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 11 clinicians in 2 Medicare specialties reassign their Medicare billing to David W. Kossoff, M.D., LLC. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. The largest specialties are Nurse Practitioner (6) and Gastroenterology (5). Of these, 4 practice at this address and 6 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does David W. Kossoff, M.D., LLC hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 21D1037930) is associated with this NPI, valid through March 7, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

When was this NPI record last updated?

The NPPES record for David W. Kossoff, M.D., LLC was last updated on May 19, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 17 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.