1. Home
  2. Directory
  3. Maryland
  4. Baltimore
  5. Specialist
  6. NPI Profile

DR. KARL W DIEHN M.D.
NPI 1467466623
Specialist in Baltimore, MD

Active since July 27, 2006PECOS Enrolled
6565 N CHARLES ST, SUITE 601, BALTIMORE, MD 21204(410) 821-5151(410) 823-8309 Get Directions Write a Review

NPPES record last updated: December 13, 2013. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. Karl W Diehn M.d. NPPES

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

DR. KARL W DIEHN M.D. (NPI 1467466623) is an individual specialist in Baltimore, Maryland, licensed in Maryland (D0019874) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1467466623
Entity TypeIndividualMale
Primary Taxonomy174400000X
Provider Legal NameDR. KARL W DIEHNCredential: M.D.
Location Address6565 N CHARLES ST, SUITE 601Baltimore, MD 21204-6800
Mailing Address6565 N Charles St, Suite 601Baltimore, MD 21204-6800 · (410) 821-5151 · Fax (410) 823-8309
Phone(410) 821-5151
Fax(410) 823-8309
Sole ProprietorYes
Enumeration DateJuly 27, 2006
Last NPPES UpdateDecember 13, 2013
✔ NPI 1467466623 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers
Taxonomy Code174400000X
License✔ Licensed in MD · D0019874
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.
6565 N CHARLES ST, Baltimore, MD 21204
Open in Google Maps ↗

Other Identifiers 2

Medicare ID-Type UnspecifiedH522MD
Medicare UPINB66933MD

Group Practice 1

Group TaxonomyThis provider is a business group of one or more individual practitioners, who practice with different areas of specialization.193200000X MULTI-SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Karl W Diehn M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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.

Medicare Billing Reassignment

Medicare enrollment records show Karl Diehn reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Greater Baltimore Medical Center, Inc.
Same address
Vascular Surgery
6569 N CHARLES ST, STE 701
Baltimore, MD 21204
  • Reassigned Medicare billing, Maryland enrollment
  • 444 clinicians in this Medicare group
NPI 1528096377 (443) 849-3431

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

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.

GAIL PATRICIA NUETZEL CRNP
Nurse Practitioner (Adult Health)
6565 N CHARLES ST, SUITE 512
TOWSON, MD 21204
Baltimore County (410) 583-0300
DR. SANJITI PODURY MD
Student in an Organized Health Care Education/Training Program
6565 N CHARLES ST
TOWSON, MD 21204
Baltimore County (443) 849-3760
RICELY AND SCHECHTER PA
Nurse Practitioner (Adult Health)
6565 N CHARLES ST, SUITE 615
TOWSON, MD 21204
Baltimore County (410) 339-7910
MS. CYNTHIA ANN FANNON AUD
Audiologist
6565 N CHARLES ST, SUITE 601
BALTIMORE, MD 21204
Baltimore County (410) 821-5151
DR. COURTENAY HYLTON MORROW D.O.
Family Medicine
6565 N CHARLES ST, PPE SUITE 411
BALTIMORE, MD 21204
Baltimore County (443) 849-2707
CHILDREN'S SURGICAL ASSOCIATES, LLC
Surgery (Pediatric Surgery)
6565 N CHARLES ST, STE 305
BALTIMORE, MD 21204
Baltimore County (443) 849-6201
DR. HMU MINN M.D.
Internal Medicine
6565 N CHARLES ST, STE 203
BALTIMORE, MD 21204
Baltimore County (443) 849-3760
FAWAD KHALIQ
Internal Medicine
6565 N CHARLES ST, PPE 203
TOWSON, MD 21204
Baltimore County (443) 849-3760

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 Karl Diehn's NPI number?

The NPI number for Karl Diehn is 1467466623. It was assigned to this individual provider in the NPPES registry on July 27, 2006.

Where is Karl Diehn located?

Karl Diehn practices at 6565 N Charles St Suite 601, Baltimore, MD 21204. The listed phone number is (410) 821-5151.

What is Karl Diehn's specialty?

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

Is Karl Diehn enrolled in Medicare?

Yes. Karl Diehn is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Karl Diehn's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Karl Diehn reassigns Medicare benefits to Greater Baltimore Medical Center, Inc. (Baltimore, MD). The 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 Karl Diehn's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Karl Diehn was last updated on December 13, 2013. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 years 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.