Alyssa Arenstein, NNP-BC, DNP
Alyssa Arenstein, NNP-BC, DNP is a Critical Care Neonatal Nurse Practitioner in Aurora, CO, registered under NPI 1689244667. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty. 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 13123 E 16TH AVE, Aurora, CO 80045. 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 |
|---|---|---|
| APN.0996686 | CO | Critical Care Neonatal Nurse Practitioner primary |
| APN.0996686-NP | CO | Neonatal Nurse Practitioner |
This provider holds licence APN.0996686 issued in CO. 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 Neonatal, Critical Care covers
Definition to come... NUCC Health Care Provider Taxonomy, code 363LN0005X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 363LN0005X | Critical Care Neonatal Nurse Practitioner Neonatal, Critical Care | APN.0996686 | CO | primary |
| 363LN0000X | Neonatal Nurse Practitioner Neonatal | APN.0996686-NP | CO | |
| 390200000X | Student in an Organized Health Care Education/Training Program | — | CO |
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 | 1689244667 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 30, 2021 |
| Last updated | Aug 10, 2021 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | NNP-BC, DNP |
| Practice address |
13123 E 16TH AVE Aurora, CO 80045 (720) 777-1234 |
| Mailing address |
3121 N HUMBOLDT ST Denver, CO 80205 |
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 | 6 | 8 | 9 | 2 | 4 | 4 | 6 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 7 | 9 | 4 | 4 | 8 | 6 | 3 |
Sum = 73 · next multiple of 10 = 80 · check digit = 7 · actual last digit = 7
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.