2026 NPPES data Rheumatology Physician NPI 1225122716 M.D.
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WILLIAM CHAFIN, M.D.

Rheumatology Physician in GAINESVILLE, Georgia. 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
6K
Medicare Part D claims · 782 beneficiaries · Rheumatology Physician avg: 2K
Generic prescribing
82%
generic claims · 18% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
96.0864/100
▲ 13 pts above national avg 83.1 · [object Object]
Industry payments
$4.6K
211 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WILLIAM CHAFIN, M.D. reported a CMS MIPS final score of 96.0864/100 — above the 83.1 national average — and filed 5,702 Medicare Part D claims in 2023.

96.0864/100
MIPS score · +13 vs avg
6K
Part D claims, 2023
82%
generic prescribing
Likely
board-certified (heuristic)

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.

WILLIAM CHAFIN, M.D.'s MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

96 Top 17% higher than 83% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). Below this entry. 80–90: 129,887 scored providers (27%). Below this entry. 90–100: 189,403 scored providers (40%). This entry sits in this band. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

Board certification likely (heuristic — not verified)

WILLIAM CHAFIN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about WILLIAM CHAFIN, M.D.?

High performer (top quartile)

NPI registry status

Active

Issued 10/02/2006

NPI 1225122716

Primary specialty

Rheumatology Physician

Mid-sized

6,181 US NPIs in this specialty

Medicare Part D claims

5,702 178% vs specialty avg

2023 prescription claims

Specialty avg: 2,054

MIPS final score

96.0864/100 12.986400000000003% pts

Exceptional band

vs 83.1 national avg

Specialty distribution in Georgia

How Rheumatology Physician compares to other specialties among Georgia providers

Georgia providers

Rheumatology Physician share within Georgia

1. Rheumatology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Rheumatology Physician share within Georgia

Medicare quality performance — MIPS

WILLIAM CHAFIN, M.D.'s 2023 MIPS final score plotted against the Rheumatology Physician national average

High performer (top quartile)
MIPS Final Score
96.0864/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Rheumatology Physician) — 96.0864/100 vs national avg 83.1

0%100%National avg83%96.1%
MIPS final score (Rheumatology Physician) — 96.0864/100 vs national avg 83.1

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).

WILLIAM CHAFIN, M.D. appears in the CMS NPPES registry as a Rheumatology Physician provider holding M.D. credentials at 700 S ENOTA DR NE, GAINESVILLE, GA, 30501, with a listed phone of (770) 531-3711. NPI 1225122716 was issued on 10/02/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHAFIN 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 5,702 prescription claims written by this provider, covering 782 Medicare beneficiaries and totaling roughly $6.4 million in drug spend, split 18% brand-name and 82% generic by claim count, with an opioid prescribing rate of 4.2%. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 96.0864/100 for the 2023 performance year (Quality 92.1728), compared with the national average of 83.1.

Rheumatology Physician is a mid-sized specialty nationwide, with 6,181 enrolled providers across 52 states and an average of 2,054 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

700 S ENOTA DR NE
GAINESVILLE, GA 30501

Provider Details

NPI 1225122716
Specialty Rheumatology Physician
Credentials M.D.
Gender Male
NPI Issued 10/02/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

96.0864
Final Score
Avg: 83.1
92.1728
Quality
100
Promoting Interoperability

Reporting: Alternative Payment Model

Hospital and facility affiliations

Facilities where WILLIAM CHAFIN, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

SOUTHEASTERN RHEUMATOLOGY ALLIANCE
GAINESVILLE, GA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for WILLIAM CHAFIN, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$4.6K

Largest payer

ABBVIE INC.

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

Brand vs generic prescribing mix · Typical

WILLIAM CHAFIN, M.D. — brand share 18.0%
Specialty average (est.)

18% brand-name claims vs 82% generic, on 5,702 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.

5,702
Total Claims
$6.4M
Total Drug Cost
782
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
11,215
Total Day Supply
326,472
Brand vs Generic
18% brand / 82% generic
Brand Drug Cost
$6.2M
Generic Drug Cost
$204K
Opioid Claims
240 (4.2% rate)
Antibiotic Claims
30

Patient Demographics

Average Patient Age
72.5 years
Avg HCC Risk Score
1.60
Gender Split
74% female / 26% male
Age Distribution
<65: 94, 65-74: 364, 75-84: 271, 85+: 53

Top Prescribed Drugs (Medicare Part D)

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

What WILLIAM CHAFIN, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Hydroxychloroquine Sulfate
1,113
Methotrexate
Methotrexate Sodium
1,036
Prednisone
869
Enbrel Sureclick
Etanercept
255
Humira(Cf) Pen
Adalimumab
254
Orencia Clickject
Abatacept
157
Diclofenac Sodium
139
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
138
Leucovorin Calcium
117
Gabapentin
116

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

Rheumatology Physician Overview

How WILLIAM CHAFIN, M.D. fits within the Rheumatology Physician landscape nationally.

6,181
Rheumatology Physician Providers in US
52
States with Rheumatology Physician
2,054
Avg Claims per Provider

WILLIAM CHAFIN, M.D.'s 5,702 claims are above the specialty average of 2,054.

Nearby Rheumatology Physician Providers in Georgia

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

Compare Rheumatology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is WILLIAM CHAFIN, M.D.'s specialty?
WILLIAM CHAFIN, M.D. specializes in Rheumatology Physician and practices in GAINESVILLE, Georgia. Credentials: M.D..
How much does WILLIAM CHAFIN, M.D. prescribe under Medicare Part D?
In 2023, WILLIAM CHAFIN, M.D. wrote 5,702 Medicare Part D claims totaling $6.4M in drug costs for 782 beneficiaries.
What is WILLIAM CHAFIN, M.D.'s Medicare quality score?
WILLIAM CHAFIN, M.D. has a CMS MIPS Final Score of 96.0864/100 (Quality: 92.1728). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is WILLIAM CHAFIN, M.D. located?
WILLIAM CHAFIN, M.D. is located at 700 S ENOTA DR NE, GAINESVILLE, GA, 30501. Phone: (770) 531-3711.
What is WILLIAM CHAFIN, M.D.'s NPI number?
WILLIAM CHAFIN, M.D.'s National Provider Identifier (NPI) is 1225122716, issued on 10/02/2006.
Does WILLIAM CHAFIN, M.D. prescribe more brand-name or generic drugs?
WILLIAM CHAFIN, M.D.'s prescribing is 18% brand-name and 82% generic drugs by claim count, with $6.2M in brand drug costs.
Does WILLIAM CHAFIN, M.D. prescribe opioids?
Yes, WILLIAM CHAFIN, M.D. had 240 opioid claims in 2023 with an opioid prescribing rate of 4.2%.
How many Rheumatology Physician providers are there in the US?
There are 6,181 Rheumatology Physician providers across 52 states in the US. The average Rheumatology Physician provider writes 2,054 Medicare Part D claims per year.
What drugs does WILLIAM CHAFIN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, WILLIAM CHAFIN, M.D.'s most frequently prescribed drugs include Hydroxychloroquine Sulfate, Methotrexate, Prednisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WILLIAM CHAFIN, M.D. accept Medicare?
WILLIAM CHAFIN, M.D. appears in CMS Medicare data with 5,702 Part D claims and 782 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WILLIAM CHAFIN, M.D.'s credentials?
WILLIAM CHAFIN, M.D.'s NPI is 1225122716 with credentials M.D.. 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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