Melissa Ryan, RN
NPI 1558230938 · Hematology & Oncology Physician · San Francisco, CA
Melissa Ryan, RN is a Hematology & Oncology Physician provider in San Francisco, CA (NPI 1558230938).
Provider details
- NPI number
- 1558230938
- Entity type
- Individual
- Primary specialty
- Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- RN
- Sex
- Female
- Sole proprietor
- No
- License
- 689841 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
Under 1 yr in registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2025-11-03
- Last updated
- 2025-11-03
- Certified
- 2025-11-03
Frequently asked questions
- What is Melissa Ryan's NPI number?
- Melissa Ryan's National Provider Identifier (NPI) is 1558230938, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Melissa Ryan's specialty?
- Melissa Ryan is listed in the NPPES registry with a primary specialty of Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Melissa Ryan located?
- Melissa Ryan's practice location on file with NPPES is 505 Parnassus Ave, San Francisco, CA 94143-2204.
- What is Melissa Ryan's phone number?
- The practice phone number listed in the NPPES registry for Melissa Ryan is (415) 353-1383.
- Is Melissa Ryan's NPI active?
- Yes — Melissa Ryan's NPI (1558230938) is active in the NPPES registry as of the last update on 2025-11-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.