NPI Portal NPI Lookup & Verification

Mark T. Grattan, MD, LLC

Mark T. Grattan, MD, LLC is a healthcare organization registered as Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician in Honolulu, HI, holding Type 2 (organization) NPI 1043413040 since 2007. The authorized official on file is Mark Grattan, Sole Proprietor.

✓ Active NPI ✓ Valid NPI checksum

NPI 1043413040
Entity type Organization (Type 2)
Legal business name Mark T. Grattan, MD, LLC
Practice address 888 S KING ST, Honolulu, HI, 96813
Phone 8085223068
Enumeration date 2007-06-07
Last updated in NPPES 2007-12-11

Authorized official

Name Mark Grattan
Title Sole Proprietor
Phone 8085223068

Taxonomy & classification

Taxonomy code Specialty Primary License State
208G00000X Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician Primary MD 7469 HI

Other identifiers

Identifier Type State Issuer
06869402 Medicaid HI
Copy-ready billing details
Provider: Mark T. Grattan, MD, LLC
NPI: 1043413040
Taxonomy: 208G00000X (Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician)
Address: 888 S KING ST, Honolulu, HI, 96813

Providers at this address

NPI Name Type Specialty Location
1497745988 Eric Crawley Individual Pulmonary Disease Physician Honolulu, HI
1548242076 Cleland Child Individual Internal Medicine Physician Honolulu, HI
1952385106 Susie Chang Individual Ophthalmology Physician Honolulu, HI
1679559132 Mark Flanagan Individual Emergency Medicine Physician Honolulu, HI
1578543286 Jennie Sekiya Individual Certified Registered Nurse Anesthetist Honolulu, HI
1629058987 Jonathan Gochu Individual Gastroenterology Physician Honolulu, HI
1578536454 Straub Clinic & Hospital Organization Community/Retail Pharmacy Honolulu, HI
1477520120 Poh Leng Individual Critical Care Medicine (Internal Medicine) Physician Honolulu, HI

Verify this record

Cross-check NPI 1043413040 against the authoritative CMS record: view Mark T. Grattan, MD, LLC on the official NPPES registry .

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty. Read the full guide or validate an NPI number.

Frequently asked questions

What is a Type 2 NPI?
A Type 2 NPI identifies an organization (group practice, hospital, pharmacy, lab), while Type 1 NPIs identify individual providers. Organizations bill under their Type 2 NPI.
What type of organization is Mark T. Grattan, MD, LLC?
Mark T. Grattan, MD, LLC is registered in NPPES as a Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician (its primary provider taxonomy).

Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2007-12-11.