Individual provider

Kathleen Mackessy, FNP

Family Nurse Practitioner Hospitalist Physician

Kathleen Mackessy, FNP is a Family Nurse Practitioner in San Diego, CA, registered under NPI 1669944369. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.

Getting there

The practice address on file is 6155 CORNERSTONE CT E STE 220, San Diego, CA 92121. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.

6155 CORNERSTONE CT E STE 220, San Diego, CA 92121 Open in Google Maps →

Credentials and Medicare

State licence
LicenceStateSpecialty
NPF95010414 CA Family Nurse Practitioner primary
NPF95010414 CA Hospitalist Physician

This provider holds licence NPF95010414 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.

Medicare (PECOS)

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 Family covers

Definition to come... NUCC Health Care Provider Taxonomy, code 363LF0000X
Physician Assistants & Advanced Practice Nursing Providers Nurse Practitioner Family

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.

CodeSpecialtyLicenceState
363LF0000X Family Nurse Practitioner Family NPF95010414 CA primary
208M00000X Hospitalist Physician NPF95010414 CA

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.

NPI1669944369 valid check digit
Entity typeIndividual (NPI-1)
Enumeration dateDec 19, 2018
Last updatedNov 6, 2019
StatusActive
Sole proprietorNo
CredentialFNP
Practice address 6155 CORNERSTONE CT E STE 220
San Diego, CA 92121
(858) 458-2993
Mailing address 1021 MUSEUM CT
Oceanside, CA 92057
The last update on file is Nov 6, 2019. Providers are only required to update NPPES when their information changes, so an older date does not necessarily mean the details are wrong — but it is worth a quick call before you travel.

Number check

1669944369 passes the NPI check digit test The final digit 9 matches the value computed from the first nine digits, so this is a well-formed NPI.
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 6 9 9 4 4 3 6
Doubled? ×2 ×2 ×2 ×2 ×2 ×2 ×2
Value 8 0 8 8 0 2 6 3 9 9 4 8 3 3

Sum = 71 · next multiple of 10 = 80 · check digit = 9 · actual last digit = 9

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.

Common questions

What is NPI number 1669944369?
NPI 1669944369 is the National Provider Identifier assigned to Kathleen Mackessy, FNP in San Diego, CA. It is a 10-digit number issued by the Centers for Medicare & Medicaid Services and used on claims, referrals, and prescriptions to identify the provider.
What does Family cover?
Definition to come...
How do I contact Kathleen Mackessy, FNP?
The phone number on file with NPPES is (858) 458-2993, last updated Nov 6, 2019. Because NPPES is only updated when a provider files a change, call ahead to confirm the number and the current practice address before visiting.
Is NPI 1669944369 a valid number?
Yes. 1669944369 passes the Luhn check digit validation that CMS uses for NPI numbers, and it resolves to an active record in the registry.
How to use this page. Everything here comes from public federal records. Tips Health does not verify quality of care, confirm that a licence is currently active, or check malpractice history, and accepts no fees for placement. A listing is not a recommendation. Verify independently before seeking care.