H. Brennan, M.D.
H. Brennan, M.D. is an Otolaryngology/Facial Plastic Surgery Physician in Newport Beach, CA, registered under NPI 1558396895.
Getting there
The practice address on file is 400 NEWPORT CENTER DR STE. 100, Newport Beach, CA 92660. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| C27484 | CA | Otolaryngology/Facial Plastic Surgery… primary |
This provider holds licence C27484 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Otolaryngology/Facial Plastic Surgery covers
An otolaryngologist who specializes in the diagnosis and surgical treatment of head and neck conditions. NUCC Health Care Provider Taxonomy, code 207YX0905X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1558396895 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 12, 2006 |
| Last updated | Mar 10, 2026 |
| Status | Deactivated |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
400 NEWPORT CENTER DR STE. 100 Newport Beach, CA 92660 (949) 644-1641 |
| Mailing address |
11999 SAN VICENTE BLVD STE. 440 Los Angeles, CA 90049 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 5 | 5 | 8 | 3 | 9 | 6 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 1 | 8 | 6 | 9 | 3 | 8 | 9 |
Sum = 75 · next multiple of 10 = 80 · check digit = 5 · actual last digit = 5
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.