Malissa Hallahan
Malissa Hallahan is a Nurse Practitioner in Modesto, CA, registered under NPI 1003379207. This provider registers 2 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
Here is what surrounds this office in Modesto, based on OpenStreetMap data collected Sep 22, 2026. Parking is available about 700 ft away. A pharmacy sits 0.35 mi from the entrance (CVS Pharmacy), which helps if you leave with a prescription. If you arrive early, there is a coffee shop 0.37 mi away.
Getting here and what is nearby
Hotel Ramada Modesto Yosemite Area 445 ft ~2 min
Parking 490 ft ~2 min
Restaurant Wendy's 497 ft ~2 min
1501 McHenry Avenue
Restaurant Denny's 526 ft ~2 min
1525 McHenry Avenue
Parking 629 ft ~3 min
Parking 700 ft ~3 min
Coffee Dutch Bros. Coffee 747 ft ~3 min
Convenience Fast & Easy Mart 965 ft ~4 min
Gas station Chevron 956 ft ~4 min
Restaurant La Parrilla Mexican Restaurant & Bar 0.23 mi ~5 min
1700 McHenry Avenue, Modesto 95350
Grocery Sprouts Farmers Market 0.31 mi ~7 min
1700 McHenry Avenue, Modesto 95350
Pharmacy CVS Pharmacy 0.35 mi ~7 min
Coffee Starbucks 0.37 mi ~8 min
Grocery Safeway 0.44 mi ~9 min
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| NP95013990 | CA | Nurse Practitioner primary |
| 1-141039 | AL | Maternal Newborn Registered Nurse |
Licences are recorded in 2 states: CA, AL. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
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.
Licensed in 2 states
This provider holds licences in 2 states: Alabama and California. The practice address on file is in Modesto, CA, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- NP95013990
- Specialty
- Nurse Practitioner
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Nurse Practitioner covers
(1) A registered nurse provider with a graduate degree in nursing prepared for advanced practice involving independent and interdependent decision making and direct accountability for clinical judgment across the health care continuum or in a certified specialty. (2) A registered nurse who has completed additional training beyond basic nursing education and who provides primary health care services in accordance with state nurse practice laws or statutes. Tasks performed by nurse practitioners vary with practice requirements mandated by geographic, political, economic, and social factors. Nurse practitioner specialists include, but are not limited to, family nurse practitioners, gerontological nurse practitioners, pediatric nurse practitioners, obstetric-gynecologic nurse practitioners, and school nurse practitioners. NUCC Health Care Provider Taxonomy, code 363L00000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 363L00000X | Nurse Practitioner | NP95013990 | CA | primary |
| 163WM0102X | Maternal Newborn Registered Nurse Maternal Newborn | 1-141039 | AL |
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 | 1003379207 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 13, 2019 |
| Last updated | Mar 3, 2020 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Practice address |
1500 FLORIDA AVE Modesto, CA 95350 (866) 682-4842 Fax (877) 435-6573 |
| Mailing address |
737 W CHILDS AVE Merced, CA 95341 |
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 | 0 | 0 | 3 | 3 | 7 | 9 | 2 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 6 | 7 | 9 | 2 | 0 |
Sum = 53 · next multiple of 10 = 60 · 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.