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2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1417996109 M.D.
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Charlie Chang, M.D.

Endocrinology, Diabetes & Metabolism Physician in Webster, Texas.

This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 7,852 in Endocrinology, Diabetes & Metabolism Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.

Federal data, no proprietary rating. We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
11K
Medicare Part D claims · 1K beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
44%
generic claims · 48% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
75/100
▼ 8 pts below national avg 83.1 · Above neutral
Industry payments
$2.4K
121 payments · CMS Open Payments (Sunshine Act)
Verify NPI on CMS Methodology
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Charlie Chang, M.D. reported a CMS MIPS final score of 75/100 - below the 83.1 national average - and filed 10,638 Medicare Part D claims in 2023.

75/100
MIPS score · -8 vs avg
11K
Part D claims, 2023
44%
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.

Charlie Chang, 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+: 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

Where Charlie Chang, M.D. sits

This provider among endocrinology, diabetes & metabolism physician peers

Across the 2,521 endocrinology, diabetes & metabolism physician providers who report both Medicare Part D prescribing and a MIPS quality score, Charlie Chang, M.D. writes more Part D claims than 97% of them and scores higher on MIPS quality than 15% - placing this provider in the high-volume, lower-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.

Part D claim volume vs MIPS quality, by specialty percentile

Lower volume · High qualityHigh volume · High qualityLower volume · Lower qualityHigh volume · Lower quality02550751000255075100Part D claim volume, percentile in specialtyMIPS quality, percentilePart D claim volume, percentile in specialty: 40 · MIPS quality, percentile: 80Part D claim volume, percentile in specialty: 57 · MIPS quality, percentile: 77Part D claim volume, percentile in specialty: 63 · MIPS quality, percentile: 72Part D claim volume, percentile in specialty: 77 · MIPS quality, percentile: 48Part D claim volume, percentile in specialty: 25 · MIPS quality, percentile: 58Part D claim volume, percentile in specialty: 13 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 47 · MIPS quality, percentile: 63Part D claim volume, percentile in specialty: 28 · MIPS quality, percentile: 32Part D claim volume, percentile in specialty: 2 · MIPS quality, percentile: 48Part D claim volume, percentile in specialty: 7 · MIPS quality, percentile: 95Part D claim volume, percentile in specialty: 93 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 10 · MIPS quality, percentile: 32Part D claim volume, percentile in specialty: 80 · MIPS quality, percentile: 40Part D claim volume, percentile in specialty: 92 · MIPS quality, percentile: 68Part D claim volume, percentile in specialty: 17 · MIPS quality, percentile: 87Part D claim volume, percentile in specialty: 42 · MIPS quality, percentile: 0Part D claim volume, percentile in specialty: 58 · MIPS quality, percentile: 43Part D claim volume, percentile in specialty: 30 · MIPS quality, percentile: 55Part D claim volume, percentile in specialty: 55 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 83 · MIPS quality, percentile: 78Part D claim volume, percentile in specialty: 20 · MIPS quality, percentile: 8Part D claim volume, percentile in specialty: 18 · MIPS quality, percentile: 92Part D claim volume, percentile in specialty: 95 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 0 · MIPS quality, percentile: 98Part D claim volume, percentile in specialty: 43 · MIPS quality, percentile: 7Part D claim volume, percentile in specialty: 78 · MIPS quality, percentile: 30Part D claim volume, percentile in specialty: 12 · MIPS quality, percentile: 98Part D claim volume, percentile in specialty: 87 · MIPS quality, percentile: 70Part D claim volume, percentile in specialty: 37 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 23 · MIPS quality, percentile: 93Part D claim volume, percentile in specialty: 45 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 82 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 32 · MIPS quality, percentile: 3Part D claim volume, percentile in specialty: 48 · MIPS quality, percentile: 65Part D claim volume, percentile in specialty: 3 · MIPS quality, percentile: 28Part D claim volume, percentile in specialty: 35 · MIPS quality, percentile: 2Part D claim volume, percentile in specialty: 75 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 50 · MIPS quality, percentile: 57Part D claim volume, percentile in specialty: 22 · MIPS quality, percentile: 60Part D claim volume, percentile in specialty: 73 · MIPS quality, percentile: 42Part D claim volume, percentile in specialty: 52 · MIPS quality, percentile: 75Part D claim volume, percentile in specialty: 53 · MIPS quality, percentile: 53Part D claim volume, percentile in specialty: 68 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 33 · MIPS quality, percentile: 83Part D claim volume, percentile in specialty: 27 · MIPS quality, percentile: 47Part D claim volume, percentile in specialty: 97 · MIPS quality, percentile: 62Part D claim volume, percentile in specialty: 67 · MIPS quality, percentile: 83Part D claim volume, percentile in specialty: 85 · MIPS quality, percentile: 73Part D claim volume, percentile in specialty: 8 · MIPS quality, percentile: 10Part D claim volume, percentile in specialty: 100 · MIPS quality, percentile: 97Part D claim volume, percentile in specialty: 88 · MIPS quality, percentile: 37Part D claim volume, percentile in specialty: 38 · MIPS quality, percentile: 67Part D claim volume, percentile in specialty: 5 · MIPS quality, percentile: 45Part D claim volume, percentile in specialty: 72 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 62 · MIPS quality, percentile: 35Part D claim volume, percentile in specialty: 65 · MIPS quality, percentile: 80Part D claim volume, percentile in specialty: 90 · MIPS quality, percentile: 5Part D claim volume, percentile in specialty: 60 · MIPS quality, percentile: 38Part D claim volume, percentile in specialty: 15 · MIPS quality, percentile: 88Part D claim volume, percentile in specialty: 70 · MIPS quality, percentile: 52Charlie Chang, M.D.-Part D claim volume, percentile in specialty: 97 · MIPS quality, percentile: 15
Part D claim volume vs MIPS quality, by specialty percentile

Each dot is one endocrinology, diabetes & metabolism physician peer from a representative sample of 60; the gold marker is Charlie Chang, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.

✓
Board certification likely (heuristic, not verified)

Charlie Chang, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 2 hospital affiliations - 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 Charlie Chang, M.D.?

Below national average

NPI registry status

Active

Issued 06/06/2006

NPI 1417996109

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

10,638 303% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

MIPS final score

75/100 8.1 pts vs avg

Above neutral band

vs 83.1 national avg

Specialty distribution in Texas

How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among Texas providers

Texas providers
Behavior Technician - 5.6%Behavior Technician5.6%Student in an Organized Health Care Education/Training Program - 5.1%Student in an Organized Health Care Education/Training Program5.1%Family Nurse Practitioner - 4.5%Family Nurse Practitioner4.5%Professional Counselor - 4.4%Professional Counselor4.4%Pharmacist - 4.4%Pharmacist4.4%Speech-Language Pathologist - 3.9%Speech-Language Pathologist3.9%Endocrinology, Diabetes & Metabolism Physician - 0.1%Endocrinology, Diabetes & Metabolism Physician0.1%
Largest specialties in Texas (% of in-state providers)

Medicare quality performance, MIPS

Charlie Chang, M.D.'s 2023 MIPS final score plotted against the Endocrinology, Diabetes & Metabolism Physician national average

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

MIPS final score (Endocrinology, Diabetes & Metabolism Physician) - 75/100 vs national avg 83.1

0%100%National avg83%75%
MIPS final score (Endocrinology, Diabetes & Metabolism Physician) - 75/100 vs national avg 83.1
How MIPS and board certification work

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).

Charlie Chang, M.D. appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding M.D. credentials at 600 N KOBAYASHI STE 312, Webster, TX, 77598, with a listed phone of (281) 724-8333. NPI 1417996109 was issued on 06/06/2006.

Medicare Part D records for calendar year 2023 show 10,638 prescription claims written by this provider, covering 1,260 Medicare beneficiaries and totaling roughly $6.7 million in drug spend, split 48% brand-name and 44% generic by claim count. 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.

Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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

600 N KOBAYASHI STE 312
Webster, TX 77598
(281) 724-8333

Provider Details

NPI 1417996109
Specialty Endocrinology, Diabetes & Metabolism Physician
Credentials M.D.
Gender Male
NPI Issued 06/06/2006

CMS Quality Score (MIPS)

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

75
Final Score
Avg: 83.1

Reporting: Group practice

Hospital and facility affiliations

Facilities where Charlie Chang, 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.

Cls Health PLLC
Webster, TX
Endocrinology Clinic AT Clear Lake Specialties PLLC
Webster, TX

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 Charlie Chang, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$2.4K

Largest payer

Corcept Therapeutics

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.

License & disciplinary context - Texas TMB 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 ~77K Texas medical licensees in 2023 - they are NOT specific to Charlie Chang, M.D.. To verify Charlie Chang, M.D.'s current license status, search the TMB public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

344
Total board actions, Texas 2023
Across 334 cases
4.47
Actions per 1,000 licensees
Texas statewide rate
probation
Most common action type
94 cases

TMB 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 Texas disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Above average

Charlie Chang, M.D. - brand share 48.0%
Endocrinology, Diabetes & Metabolism Physician average

48% brand-name claims vs 44% generic, on 10,638 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.

10,638
Total Claims
$6.7M
Total Drug Cost
1,260
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
25,160
Total Day Supply
748,107
Brand vs Generic
48% brand / 44% generic
Brand Drug Cost
$6.3M
Generic Drug Cost
$190K
Antibiotic Claims
16

Patient Demographics

Average Patient Age
71.3 years
Avg HCC Risk Score
1.93
Gender Split
63% female / 37% male
Age Distribution
<65: 156, 65-74: 643, 75-84: 397, 85+: 64

Top Prescribed Drugs (Medicare Part D)

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

What Charlie Chang, 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
Ozempic
Semaglutide
694
Levothyroxine Sodium
 688
Synthroid
Levothyroxine Sodium
507
Metformin Hcl
 463
Metformin Hcl Er
Metformin Hcl
404
Jardiance
Empagliflozin
320
Pioglitazone Hcl
 271
Atorvastatin Calcium
 268
Tresiba Flextouch U-100
Insulin Degludec
234
Novolog Flexpen
Insulin Aspart
207

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

More Endocrinology, Diabetes & Metabolism Physician in TX → All providers in Texas → Compare specialties →

Endocrinology, Diabetes & Metabolism Physician Overview

How Charlie Chang, M.D. fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.

7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider

Charlie Chang, M.D.'s 10,638 claims are above the specialty average of 2,639.

Nearby Endocrinology, Diabetes & Metabolism Physician Providers in Texas

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

Dr. Nicola Abate
MD
Baytown, TX
Dr. Jessica Abramowitz
MD
Dallas, TX
Dr. Layla Abushamat
M.D., M.P.H.
Houston, TX
Dr. Luis Acosta
MD
Houston, TX
Dr. Stefanie Addington
M.D.
Frisco, TX

Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →

Before you book an appointment

Use this federal record as your verification checklist, not as a recommendation.

  • Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
  • Check the active license and any disciplinary history with the Texas medical board, federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Endocrinology, Diabetes & Metabolism Physician peer on Medicare volume and prescribing patterns. Compare providers

Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.

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Frequently Asked Questions

What is Charlie Chang, M.D.'s specialty? ▼
Charlie Chang, M.D. specializes in Endocrinology, Diabetes & Metabolism Physician and practices in Webster, Texas. Credentials: M.D..
How much does Charlie Chang, M.D. prescribe under Medicare Part D? ▼
In 2023, Charlie Chang, M.D. wrote 10,638 Medicare Part D claims totaling $6.7M in drug costs for 1,260 beneficiaries.
What is Charlie Chang, M.D.'s Medicare quality score? ▼
Charlie Chang, 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 Charlie Chang, M.D. located? ▼
Charlie Chang, M.D. is located at 600 N KOBAYASHI STE 312, Webster, TX, 77598. Phone: (281) 724-8333.
What is Charlie Chang, M.D.'s NPI number? ▼
Charlie Chang, M.D.'s National Provider Identifier (NPI) is 1417996109, issued on 06/06/2006.
Does Charlie Chang, M.D. prescribe more brand-name or generic drugs? ▼
Charlie Chang, M.D.'s prescribing is 48% brand-name and 44% generic drugs by claim count, with $6.3M in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US? ▼
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
What drugs does Charlie Chang, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Charlie Chang, M.D.'s most frequently prescribed drugs include Ozempic, Levothyroxine Sodium, Synthroid. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Charlie Chang, M.D. accept Medicare? ▼
Charlie Chang, M.D. appears in CMS Medicare data with 10,638 Part D claims and 1,260 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Charlie Chang, M.D.'s credentials? ▼
Charlie Chang, M.D.'s NPI is 1417996109 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

View source datasets and methodology notes
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

Compiled from official public sources by the PlainDoctor editorial team.