Malissa Hallahan
Nurse Practitioner β’ Modesto, CA
1500 Florida Ave
Modesto, CA 953504408
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
Practice Location & Contact Primary Location
1500 Florida Ave
Modesto, CA 953504408
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Nurse Practitioner: NPPES taxonomy is a reported classification, not proof of board certification.
Industry payments (Open Payments)
No Open Payments records are listed for this clinician for 2021β2025.
NPI first issued
2019
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians, CMS release of October 2, 2026; Medicare.gov, βDoes your provider accept Medicare as full payment?β
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians, CMS release of October 2, 2026.
Compared with the same specialty in Modesto and California
94 active clinicians are listed under Nurse Practitioner with a practice address in Modesto, CA (8,363 in California).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Modesto
14.9% of these 94 clinicians have the CMS telehealth indicator.
37.2% of these 94 clinicians are listed by CMS as accepting Medicare assignment.
Sources: CMS Doctors and Clinicians, CMS release of October 2, 2026, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo Β· Report an error.
Specialties & License Numbers Reported to NPPES
Self-certified to NPPES: 2020-03-03NUCC Taxonomy Code: 363L00000X
(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 Taxonomy Code: 163WM0102X
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Podiatrist
Doctor of Podiatric Medicine
Podiatrist - Foot & Ankle Surgery
Doctor of Podiatric Medicine
Physician Assistant
MMSMPH, Physician Assistant (Certified)
Pediatrics
Doctor of Medicine (M.D.)
Pediatrics
Doctor of Medicine (M.D.)
Nurse Practitioner - Family
Family Nurse Practitioner
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 1500 FLORIDA AVE, MODESTO, CA 953504408 (Tel: 8666824842)
Registered at 737 W CHILDS AVE, MERCED, CA 953416805
NPI status registered as active in NPPES database
Registered at 1700 6TH AVE S, BIRMINGHAM, AL 352331802 (Tel: 2059752378)
Registered at 708 PATTON CHAPEL WAY, HOOVER, AL 352262245
Recorded as MALISSA HALLAHAN
Registered Nurse (license number reported to NPPES: AL 1-141039)
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Nurse Practitioners in Modesto
- Flavia Rorison, NP
- Christle Stanton, FNP-BC
- Gulneet Kaur, NP
- Dr. Gurdeep Mann, DNP, FNP-C
- Darienne Marcetti, NP
- Susan Simon, NP
Mailing Address
737 W Childs Ave
Merced, CA 953416805