2026 NPPES data Radiology Practitioner Assistant NPI 1124275276 RPA
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MARILYN ROBERTS, RPA

Radiology Practitioner Assistant in RANCHO CUCAMONGA, California. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
What the federal data reveals: MARILYN ROBERTS, RPA is a Radiology Practitioner Assistant ([object Object]) practicing in RANCHO CUCAMONGA, California .

What stands out: MARILYN ROBERTS, RPA specializes in Radiology Practitioner Assistant and practices in RANCHO CUCAMONGA, California, listed in the federal CMS National Provider Identifier registry. Every detail on this page comes straight from federal CMS records, with no proprietary rating applied.

MARILYN ROBERTS, RPA at a glance

Quality data not reported

NPI registry status

Active

Issued 08/20/2008

NPI 1124275276

Primary specialty

Radiology Practitioner Assistant

Rare

337 US NPIs in this specialty

Specialty distribution in California

How Radiology Practitioner Assistant compares to other specialties among California providers

California providers

Radiology Practitioner Assistant share within California

1. Radiology Practitioner Assistant42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Radiology Practitioner Assistant share within California

Specialty board-certification context

Estimated specialty board-certified rate — Radiology Practitioner Assistant (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Radiology Practitioner Assistant ABMS/AOA estimate

Est. board-certified rate (Radiology Practitioner Assistant) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Radiology Practitioner Assistant) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

MARILYN ROBERTS, RPA is a Radiology Practitioner Assistant provider practicing in RANCHO CUCAMONGA, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: RPA. NPI: 1124275276. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

MARILYN ROBERTS, RPA appears in the CMS NPPES registry as a Radiology Practitioner Assistant provider holding RPA credentials at 8283 GROVE AVE, RANCHO CUCAMONGA, CA, 91730, with a listed phone of (909) 982-8638. NPI 1124275276 was issued on 08/20/2008. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ROBERTS most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D prescribing data is not currently published for this NPI, which typically means the provider either wrote fewer than 11 Part D claims in the most recent reporting year, does not participate in Medicare, or practices in a specialty that rarely prescribes outpatient drugs. Absence of prescribing data is not a quality signal — many Radiology Practitioner Assistant providers operate outside Part D entirely.

Radiology Practitioner Assistant is a narrow specialty nationwide, with 337 enrolled providers across 46 states and an average of 1,895 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

8283 GROVE AVE
RANCHO CUCAMONGA, CA 91730

Provider Details

NPI 1124275276
Specialty Radiology Practitioner Assistant
Credentials RPA
Gender Female
NPI Issued 08/20/2008

License & disciplinary context — California MBC 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 — they are NOT specific to MARILYN ROBERTS, RPA. To verify MARILYN ROBERTS, RPA's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Radiology Practitioner Assistant Overview

How MARILYN ROBERTS, RPA fits within the Radiology Practitioner Assistant landscape nationally.

337
Radiology Practitioner Assistant Providers in US
46
States with Radiology Practitioner Assistant
1,895
Avg Claims per Provider

Nearby Radiology Practitioner Assistant Providers in California

Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as ROBERTS.

Compare Radiology Practitioner Assistant nationally: see state-by-state distribution →

Frequently Asked Questions

What is MARILYN ROBERTS, RPA's specialty?
MARILYN ROBERTS, RPA specializes in Radiology Practitioner Assistant and practices in RANCHO CUCAMONGA, California. Credentials: RPA.
Where is MARILYN ROBERTS, RPA located?
MARILYN ROBERTS, RPA is located at 8283 GROVE AVE, RANCHO CUCAMONGA, CA, 91730. Phone: (909) 982-8638.
What is MARILYN ROBERTS, RPA's NPI number?
MARILYN ROBERTS, RPA's National Provider Identifier (NPI) is 1124275276, issued on 08/20/2008.
How many Radiology Practitioner Assistant providers are there in the US?
There are 337 Radiology Practitioner Assistant providers across 46 states in the US. The average Radiology Practitioner Assistant provider writes 1,895 Medicare Part D claims per year.
Does MARILYN ROBERTS, RPA accept Medicare?
MARILYN ROBERTS, RPA appears in CMS Medicare data. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MARILYN ROBERTS, RPA's credentials?
MARILYN ROBERTS, RPA's NPI is 1124275276 with credentials RPA. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology