Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mark Alan Siar

Q: What is the NPI number for Mark Siar?

The National Provider Identifier (NPI) for Mark Siar is 1174476774, a Type 1 (individual) record in the CMS NPPES registry.

Addiction (Substance Use Disorder) Counselor in Ridgeland, SC · enumerated 2026.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1174476774

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Registry record

Entity type Individual (Type 1)

Name Mark Alan Siar

Sex Male

Practice address 124 Boardwalk Dr Ste A, Ridgeland, SC, 29936

Phone (843) 645-2770

Fax (843) 645-2771

Enumeration date Feb 16, 2026

Last updated in NPPES Feb 16, 2026

Taxonomy & licenses

101YA0400X Addiction (Substance Use Disorder) Counselor Behavioral Health & Social Service Providers Primary

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 → Validate an NPI →

Frequently asked questions

What is the NPI number for Mark Siar?

The National Provider Identifier (NPI) for Mark Siar is 1174476774, a Type 1 (individual) record in the CMS NPPES registry.

Where does Mark Siar practice?

The practice location on file with NPPES is in Ridgeland, SC. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-02-16.