2026 NPPES data Physical Medicine & Rehabilitation Physician NPI 1659345890 M.D.
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WILLIAM WILLIAMSON, M.D.

Physical Medicine & Rehabilitation Physician in LOUISVILLE, Kentucky. 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
51
Medicare Part D claims · 12 beneficiaries · Physical Medicine & Rehabilitation Physician avg: 781
Generic prescribing
76%
generic claims · 24% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
75/100
▼ 8 pts below national avg 83.1 · [object Object]

What the federal data shows

WILLIAM WILLIAMSON, M.D. reported a CMS MIPS final score of 75/100 — below the 83.1 national average — and filed 51 Medicare Part D claims in 2023.

75/100
MIPS score · -8 vs avg
51
Part D claims, 2023
76%
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 WILLIAMSON, 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

75 15th percentile higher than 15% 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%). This entry sits in this band. 80–90: 129,887 scored providers (27%). Above this entry. 90–100: 189,403 scored providers (40%). Above this entry. 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 WILLIAMSON, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting — 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 WILLIAMSON, M.D.?

Below national average

NPI registry status

Active

Issued 02/15/2006

NPI 1659345890

Primary specialty

Physical Medicine & Rehabilitation Physician

Mid-sized

15,306 US NPIs in this specialty

Medicare Part D claims

51 93% vs specialty avg

2023 prescription claims

Specialty avg: 781

MIPS final score

75/100 8.099999999999994% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Kentucky

How Physical Medicine & Rehabilitation Physician compares to other specialties among Kentucky providers

Kentucky providers

Physical Medicine & Rehabilitation Physician share within Kentucky

1. Physical Medicine & Rehabilitation Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Physical Medicine & Rehabilitation Physician share within Kentucky

Medicare quality performance — MIPS

WILLIAM WILLIAMSON, M.D.'s 2023 MIPS final score plotted against the Physical Medicine & Rehabilitation Physician national average

Below national average
MIPS Final Score
75/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Physical Medicine & Rehabilitation Physician) — 75/100 vs national avg 83.1

0%100%National avg83%75%
MIPS final score (Physical Medicine & Rehabilitation Physician) — 75/100 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 WILLIAMSON, M.D. appears in the CMS NPPES registry as a Physical Medicine & Rehabilitation Physician provider holding M.D. credentials at 220 ABRAHAM FLEXNER WAY, LOUISVILLE, KY, 40202, with a listed phone of (502) 584-3376. NPI 1659345890 was issued on 02/15/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what WILLIAMSON 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 51 prescription claims written by this provider, covering 12 Medicare beneficiaries and totaling roughly $7K in drug spend, split 24% brand-name and 76% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 75/100 for the 2023 performance year, compared with the national average of 83.1.

Physical Medicine & Rehabilitation Physician is a mid-sized specialty nationwide, with 15,306 enrolled providers across 54 states and an average of 781 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

220 ABRAHAM FLEXNER WAY
LOUISVILLE, KY 40202

Provider Details

NPI 1659345890
Specialty Physical Medicine & Rehabilitation Physician
Credentials M.D.
Gender Male
NPI Issued 02/15/2006

CMS Quality Score (MIPS)

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

75
Final Score
Avg: 83.1

Reporting: Individual

Brand vs generic prescribing mix · Typical

WILLIAM WILLIAMSON, M.D. — brand share 24.0%
Specialty average (est.)

24% brand-name claims vs 76% generic, on 51 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.

51
Total Claims
$7K
Total Drug Cost
12
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
81
Total Day Supply
2,313
Brand vs Generic
24% brand / 76% generic
Brand Drug Cost
$6K
Generic Drug Cost
$611

Patient Demographics

Average Patient Age
77.7 years
Avg HCC Risk Score
4.07

Physical Medicine & Rehabilitation Physician Overview

How WILLIAM WILLIAMSON, M.D. fits within the Physical Medicine & Rehabilitation Physician landscape nationally.

15,306
Physical Medicine & Rehabilitation Physician Providers in US
54
States with Physical Medicine & Rehabilitation Physician
781
Avg Claims per Provider

WILLIAM WILLIAMSON, M.D.'s 51 claims are below the specialty average of 781.

Nearby Physical Medicine & Rehabilitation Physician Providers in Kentucky

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

Compare Physical Medicine & Rehabilitation Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is WILLIAM WILLIAMSON, M.D.'s specialty?
WILLIAM WILLIAMSON, M.D. specializes in Physical Medicine & Rehabilitation Physician and practices in LOUISVILLE, Kentucky. Credentials: M.D..
How much does WILLIAM WILLIAMSON, M.D. prescribe under Medicare Part D?
In 2023, WILLIAM WILLIAMSON, M.D. wrote 51 Medicare Part D claims totaling $7K in drug costs for 12 beneficiaries.
What is WILLIAM WILLIAMSON, M.D.'s Medicare quality score?
WILLIAM WILLIAMSON, M.D. has a CMS MIPS Final Score of 75/100. The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is WILLIAM WILLIAMSON, M.D. located?
WILLIAM WILLIAMSON, M.D. is located at 220 ABRAHAM FLEXNER WAY, LOUISVILLE, KY, 40202. Phone: (502) 584-3376.
What is WILLIAM WILLIAMSON, M.D.'s NPI number?
WILLIAM WILLIAMSON, M.D.'s National Provider Identifier (NPI) is 1659345890, issued on 02/15/2006.
Does WILLIAM WILLIAMSON, M.D. prescribe more brand-name or generic drugs?
WILLIAM WILLIAMSON, M.D.'s prescribing is 24% brand-name and 76% generic drugs by claim count, with $6K in brand drug costs.
How many Physical Medicine & Rehabilitation Physician providers are there in the US?
There are 15,306 Physical Medicine & Rehabilitation Physician providers across 54 states in the US. The average Physical Medicine & Rehabilitation Physician provider writes 781 Medicare Part D claims per year.
Does WILLIAM WILLIAMSON, M.D. accept Medicare?
WILLIAM WILLIAMSON, M.D. appears in CMS Medicare data with 51 Part D claims and 12 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WILLIAM WILLIAMSON, M.D.'s credentials?
WILLIAM WILLIAMSON, M.D.'s NPI is 1659345890 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