Marissa May, MS, RDN
Marissa May, MS, RDN is an Oncology Nutrition Registered Dietitian in Coral Gables, FL, registered under NPI 1801431796. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 4251 SALZEDO ST, Coral Gables, FL 33146. 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
NPPES does not list a state licence number for this record. That is not unusual — organizations and some provider types are not required to file one. Verify current licensure with the relevant state board before care.
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 Nutrition, Oncology covers
An individual who is a Board Certified Specialist in Oncology Nutrition and provides direct nutrition care for individuals at risk for or diagnosed with cancer. RDNs working directly with individuals at risk for, or diagnosed with, any type of malignancy or pre-malignant condition, in a variety of settings (e.g. hospitals, clinics, cancer centers, hospices, public health), OR indirectly through roles in management, education, industry, and research practice linked specifically to oncology nutrition. RDN who works indirectly with oncology nutrition through roles in management, education, industry, and research. NUCC Health Care Provider Taxonomy, code 133VN1301X
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 | 1801431796 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 14, 2019 |
| Last updated | Aug 28, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MS, RDN |
| Practice address |
4251 SALZEDO ST Coral Gables, FL 33146 (561) 621-0079 |
| Mailing address |
4251 SALZEDO ST UNIT 606 Coral Gables, FL 33146 |
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 | 8 | 0 | 1 | 4 | 3 | 1 | 7 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 0 | 1 | 8 | 3 | 2 | 7 | 9 |
Sum = 64 · next multiple of 10 = 70 · check digit = 6 · actual last digit = 6
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.