2026 NPPES data Medical Physician Assistant NPI 1861625683 PA-C
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GREGORY CHAMBERS, PA-C

Medical Physician Assistant in COLUMBIA, South Carolina. 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.
Prescribing volume
33
Medicare Part D claims · 24 beneficiaries · Medical Physician Assistant avg: 1K
Generic prescribing
58%
generic claims · 42% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

GREGORY CHAMBERS, PA-C filed 33 Medicare Part D claims in 2023 as a Medical Physician Assistant in COLUMBIA, South Carolina, prescribing 58% generic.

33
Part D claims, 2023
58%
generic prescribing

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

GREGORY CHAMBERS, PA-C's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

33 0th percentile higher than 0% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

What does the federal data show about GREGORY CHAMBERS, PA-C?

Quality data not reported

NPI registry status

Active

Issued 08/27/2009

NPI 1861625683

Primary specialty

Medical Physician Assistant

Mid-sized

40,527 US NPIs in this specialty

Medicare Part D claims

33 97% vs specialty avg

2023 prescription claims

Specialty avg: 1,077

Specialty distribution in South Carolina

How Medical Physician Assistant compares to other specialties among South Carolina providers

South Carolina providers

Medical Physician Assistant share within South Carolina

1. Medical Physician Assistant42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Medical Physician Assistant share within South Carolina

Specialty board-certification context

Estimated specialty board-certified rate — Medical Physician Assistant (ABMS / AOA reference)

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

Est. board-certified rate (Medical Physician Assistant) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Medical Physician 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).

GREGORY CHAMBERS, PA-C is a Medical Physician Assistant provider practicing in COLUMBIA, South Carolina, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: PA-C. NPI: 1861625683. 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.

GREGORY CHAMBERS, PA-C appears in the CMS NPPES registry as a Medical Physician Assistant provider holding PA-C credentials at SC HOUSE CALLS INC, COLUMBIA, SC, 29203, with a listed phone of (800) 491-0909. NPI 1861625683 was issued on 08/27/2009. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHAMBERS 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 records for calendar year 2023 show 33 prescription claims written by this provider, covering 24 Medicare beneficiaries and totaling roughly $6K in drug spend, split 42% brand-name and 58% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Medical Physician Assistant is a mid-sized specialty nationwide, with 40,527 enrolled providers across 55 states and an average of 1,077 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

SC HOUSE CALLS INC
COLUMBIA, SC 29203

Provider Details

NPI 1861625683
Specialty Medical Physician Assistant
Credentials PA-C
Gender Male
NPI Issued 08/27/2009

Brand vs generic prescribing mix · Above average

GREGORY CHAMBERS, PA-C — brand share 42.0%
Specialty average (est.)

42% brand-name claims vs 58% generic, on 33 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

33
Total Claims
$6K
Total Drug Cost
24
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
83
Total Day Supply
2,400
Brand vs Generic
42% brand / 58% generic
Brand Drug Cost
$4K
Generic Drug Cost
$1K
Antibiotic Claims
15

Patient Demographics

Average Patient Age
75.3 years
Avg HCC Risk Score
2.32

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Trimethoprim
14

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Medical Physician Assistant Overview

How GREGORY CHAMBERS, PA-C fits within the Medical Physician Assistant landscape nationally.

40,527
Medical Physician Assistant Providers in US
55
States with Medical Physician Assistant
1,077
Avg Claims per Provider

GREGORY CHAMBERS, PA-C's 33 claims are below the specialty average of 1,077.

Nearby Medical Physician Assistant Providers in South Carolina

Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as CHAMBERS.

Compare Medical Physician Assistant nationally: see state-by-state distribution →

Frequently Asked Questions

What is GREGORY CHAMBERS, PA-C's specialty?
GREGORY CHAMBERS, PA-C specializes in Medical Physician Assistant and practices in COLUMBIA, South Carolina. Credentials: PA-C.
How much does GREGORY CHAMBERS, PA-C prescribe under Medicare Part D?
In 2023, GREGORY CHAMBERS, PA-C wrote 33 Medicare Part D claims totaling $6K in drug costs for 24 beneficiaries.
Where is GREGORY CHAMBERS, PA-C located?
GREGORY CHAMBERS, PA-C is located at SC HOUSE CALLS INC, COLUMBIA, SC, 29203. Phone: (800) 491-0909.
What is GREGORY CHAMBERS, PA-C's NPI number?
GREGORY CHAMBERS, PA-C's National Provider Identifier (NPI) is 1861625683, issued on 08/27/2009.
Does GREGORY CHAMBERS, PA-C prescribe more brand-name or generic drugs?
GREGORY CHAMBERS, PA-C's prescribing is 42% brand-name and 58% generic drugs by claim count, with $4K in brand drug costs.
How many Medical Physician Assistant providers are there in the US?
There are 40,527 Medical Physician Assistant providers across 55 states in the US. The average Medical Physician Assistant provider writes 1,077 Medicare Part D claims per year.
What drugs does GREGORY CHAMBERS, PA-C prescribe most often?
Based on 2023 Medicare Part D data, GREGORY CHAMBERS, PA-C's most frequently prescribed drugs include Trimethoprim. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GREGORY CHAMBERS, PA-C accept Medicare?
GREGORY CHAMBERS, PA-C appears in CMS Medicare data with 33 Part D claims and 24 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GREGORY CHAMBERS, PA-C's credentials?
GREGORY CHAMBERS, PA-C's NPI is 1861625683 with credentials PA-C. 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.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
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