Roanna Siangio, DMD
Dentist · Downey, CA
Roanna Siangio, DMD is a dentist with a practice address in Downey, California, and NPI 1134217052, issued on Oct 10, 2006. Check the license (California 42421, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Roanna Siangio
- Credential
- DMD
- Primary taxonomy
- Dentist 122300000X
- License number
- 42421 CA
Self-reported in NPPES; status is on the state search - Practice location
- 9474 Firestone Blvd, Downey, CA 90241
- Phone
- (562) 803-4224
- Enumerated
- Oct 10, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest dentist records → All 14,729 in California → Look up another NPI →
Also registered at 9474 Firestone Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Jettie Uyanne, DDSOral and Maxillofacial Surgery (Dentist)1972681104
- Wendy Wong, D.D.S.General Practice Dentistry1780086017
Verify Roanna Siangio in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 42421Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
59% more Medicare Part D claims than the average dentist in 2024
137 Medicare Part D claims for 71 beneficiaries, against an average of 86 among the 51,021 providers of this specialty who prescribed in Part D.
Most prescribed
- Ibuprofen46 claims
- Penicillin V Potassium43 claims
- Chlorhexidine Gluconate19 claims
- Amoxicillin12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Roanna Siangio among 14,729 dentist records in California
Roanna Siangio, DMD is one of 14,729 dentist records with a practice address in California. 56% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 2% of them.
- NPI issued2006 · 2% of these records are older, 82% newer
- In a Medicare fileYes · 56% of these records are
- In the CMS Doctors and Clinicians fileNo · under 1% of these records are
- Record last updated2007 · 73% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 122300000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
71 dentist records list a practice address in Downey
They are 71 of the 3,607 NPPES records with a practice address in Downey, and 14,729 dentist records in California.
All 14,729 in California → Every provider in Downey → Dentist nationwide →
The 8 dentist records with the nearest ZIP codes
- Behzad Abadi, DMDDowney, CA 902411588879100
- Steve Aivazian, DDSDowney, CA 902411902952633
- Samia Ali, DDSDowney, CA 902411508958794
- Neal Brown, DDSDowney, CA 902411619295862
- Jiwon KimDowney, CA 902411952611089
- Flora Lara, DDSDowney, CA 902411700947983
- Scott Mao, DDSDowney, CA 902411417178872
- Gerardo Mercado, D.D.S.Downey, CA 902411366757999
Common questions
What is Roanna Siangio, DMD's NPI number?
Roanna Siangio, DMD's National Provider Identifier (NPI) is 1134217052, issued on Oct 10, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Roanna Siangio, DMD located?
The NPPES record lists a practice address at 9474 Firestone Blvd, Downey, CA, 90241. Phone: (562) 803-4224. Providers update this record themselves, so call before visiting.
How can I verify Roanna Siangio, DMD's license?
NPPES lists California license number 42421, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Roanna Siangio, DMD prescribe under Medicare Part D?
In 2024, Roanna Siangio, DMD had 137 Medicare Part D claims for 71 beneficiaries; the average among dentist prescribers was 86. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.