Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Maureen Ursula Welker, MSN, NPC, CCRN

Individual provider Family Nurse Practitioner · NPI 1386608438

Maureen Ursula Welker, MSN, NPC, CCRN is a Nurse Practitioner in Mission Viejo, California. Qualified in 1998, 28 years ago. Practices with Oso Specialty Infusion Inc, a 10-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
28
Licensed in
CA
In the registry since
2006
Specialties on file
2
What do these letters mean?
MSN — Master of Science in Nursing
A graduate nursing degree, usually held alongside an advanced practice licence.

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Practice location Address checks out

26800 Crown Valley Pkwy Ste 330
Mission Viejo, CA 92691-6384
Phone: (929) 364-7246
Fax: (949) 364-1647
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Nurse Practitioner (primary) Taxonomy 363LF0000X · Licence 10596 (CA)
Family Nurse Practitioner Taxonomy 363LF0000X · Licence RN390049 (CA)

Record details

NPI number1386608438
Entity typeIndividual (Type 1)
GenderFemale
Credentials MSN , NPC , CCRN
Sole proprietorNo
NPI enumeratedApril 14, 2006
Last updated in NPPESNovember 11, 2021
Certification dateNovember 11, 2021

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyNURSE PRACTITIONER
Medical schoolOTHER
Graduated 1998 (28 years in practice)
Group practice Oso Specialty Infusion Inc — 10 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients102
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $115 3 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Colleagues at Oso Specialty Infusion Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 10 clinicians in the practice; 7 are shown here.

Other providers in Mission Viejo