Deana Dy, M.D.
Deana Dy, M.D. is an Allergy & Immunology Physician in Crystal Lake, IL, registered under NPI 1518950781. 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 25 S VIRGINIA ST SUITE 203, Crystal Lake, IL 60014. 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 |
|---|---|---|
| 036-057986 | IL | Allergy & Immunology Physician primary |
This provider holds licence 036-057986 issued in IL. 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 Allergy & Immunology covers
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system. NUCC Health Care Provider Taxonomy, code 207K00000X
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 | 1518950781 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 23, 2005 |
| Last updated | Jul 8, 2007 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | M.D. |
| Practice address |
25 S VIRGINIA ST SUITE 203 Crystal Lake, IL 60014 (815) 459-5440 |
| Other identifiers |
BCBS4901048
· Other (IL) |
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 | 1 | 8 | 9 | 5 | 0 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 2 | 8 | 9 | 5 | 0 | 7 | 7 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
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.