NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1831188572 M.D.,P.A.
Verify on CMS → Terry Chambless, M.D.,P.A.
Internal Medicine Physician in Round Rock, 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 172,737 in Internal Medicine 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
6K
Medicare Part D claims · 268 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
82%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$523.62
45 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Terry Chambless, M.D.,P.A. filed 6,466 Medicare Part D claims in 2023 as an Internal Medicine Physician in Round Rock, Texas, prescribing 82% generic.
- 6K
- Part D claims, 2023
- 82%
- generic prescribing
- $523.62
- industry payments (Sunshine Act)
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.
Terry Chambless, M.D.,P.A.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
6,466 Top 4% higher than 96% of 1,370,886 prescribers
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
◑
Board-eligible specialty (heuristic, not verified)
Terry Chambless, M.D.,P.A. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Terry Chambless, M.D.,P.A.?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
6,466 138% vs specialty avg
Specialty distribution in Texas
How Internal Medicine Physician compares to other specialties among Texas providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Internal Medicine Physician. Verify directly:
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).
Terry Chambless, M.D.,P.A. appears in the CMS NPPES registry as an Internal Medicine Physician provider holding M.D.,P.A. credentials at 7200 WYOMING SPGS, Round Rock, TX, 78681, with a listed phone of (512) 244-1683. NPI 1831188572 was issued on 10/16/2005.
Medicare Part D records for calendar year 2023 show 6,466 prescription claims written by this provider, covering 268 Medicare beneficiaries and totaling roughly $929K in drug spend, split 17% brand-name and 82% generic by claim count, with an opioid prescribing rate of 2.8%.
Internal Medicine Physician is a high-volume specialty nationwide, with 172,737 enrolled providers across 56 states and an average of 2,716 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
Provider Details
| NPI | 1831188572 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | M.D.,P.A. |
| Gender | Male |
| NPI Issued | 10/16/2005 |
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 Terry Chambless, M.D.,P.A.. Source: openpaymentsdata.cms.gov.
Total received
$524
Largest payer
Amgen 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.
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 Terry Chambless, M.D.,P.A.. To verify Terry Chambless, M.D.,P.A.'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 · Typical
Terry Chambless, M.D.,P.A. - brand share 17.0%
Internal Medicine Physician average
17% brand-name claims vs 82% generic, on 6,466 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.
6,466
Total Claims
$929K
Total Drug Cost
268
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 13,973
- Total Day Supply
- 397,385
- Brand vs Generic
- 17% brand / 82% generic
- Brand Drug Cost
- $747K
- Generic Drug Cost
- $180K
- Opioid Claims
- 182 (2.8% rate)
- Antibiotic Claims
- 225
Patient Demographics
- Average Patient Age
- 76.1 years
- Avg HCC Risk Score
- 1.09
- Gender Split
- 54% female / 46% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Terry Chambless, M.D.,P.A. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Rosuvastatin Calcium
Rosuvastatin Calcium
570 claims
- Ezetimibe
Ezetimibe
485 claims
- Pioglitazone Hcl
Pioglitazone Hcl
284 claims
- Levothyroxine Sodium
Levothyroxine Sodium
263 claims
- Olmesartan Medoxomil 223
Olmesartan Medoxomil
223 claims
- Liothyronine Sodium 198
Liothyronine Sodium
198 claims
- Repatha Sureclick 196
Repatha Sureclick
196 claims
- Pantoprazole Sodium 141
Pantoprazole Sodium
141 claims
| Drug | Claims |
|---|---|
| Rosuvastatin Calcium | 570 |
| Ezetimibe | 485 |
| Pioglitazone Hcl | 284 |
| Levothyroxine Sodium | 263 |
| Olmesartan Medoxomil | 223 |
| Liothyronine Sodium | 198 |
| Repatha Sureclick Evolocumab | 196 |
| Pantoprazole Sodium | 141 |
| Olmesartan-Hydrochlorothiazide Olmesartan/Hydrochlorothiazide | 134 |
| Omeprazole | 129 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Terry Chambless, M.D.,P.A. fits within the Internal Medicine Physician landscape nationally.
172,737
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
Terry Chambless, M.D.,P.A.'s 6,466 claims are above the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in Texas
Other clinicians with the same primary specialty enrolled in Texas, drawn from the same CMS NPPES roster as Chambless.
Dr. Muhammad A. Sattar
MD
Dallas, TX
Anunaya Aashish
Denton, TX
Dr. Queenie Ann Abad
M.D.
San Antonio, TX
Dr. Fuad Abaleka
M.D
Lubbock, TX
Dr. Carol Abalihi
M.D.
El Paso, TX
Compare Internal Medicine 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 Internal Medicine 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 Terry Chambless, M.D.,P.A.'s specialty? ▼
Terry Chambless, M.D.,P.A. specializes in Internal Medicine Physician and practices in Round Rock, Texas. Credentials: M.D.,P.A..
How much does Terry Chambless, M.D.,P.A. prescribe under Medicare Part D? ▼
In 2023, Terry Chambless, M.D.,P.A. wrote 6,466 Medicare Part D claims totaling $929K in drug costs for 268 beneficiaries.
Where is Terry Chambless, M.D.,P.A. located? ▼
Terry Chambless, M.D.,P.A. is located at 7200 WYOMING SPGS, Round Rock, TX, 78681. Phone: (512) 244-1683.
What is Terry Chambless, M.D.,P.A.'s NPI number? ▼
Terry Chambless, M.D.,P.A.'s National Provider Identifier (NPI) is 1831188572, issued on 10/16/2005.
Does Terry Chambless, M.D.,P.A. prescribe more brand-name or generic drugs? ▼
Terry Chambless, M.D.,P.A.'s prescribing is 17% brand-name and 82% generic drugs by claim count, with $747K in brand drug costs.
Does Terry Chambless, M.D.,P.A. prescribe opioids? ▼
Yes, Terry Chambless, M.D.,P.A. had 182 opioid claims in 2023 with an opioid prescribing rate of 2.8%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,737 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Terry Chambless, M.D.,P.A. prescribe most often? ▼
Based on 2023 Medicare Part D data, Terry Chambless, M.D.,P.A.'s most frequently prescribed drugs include Rosuvastatin Calcium, Ezetimibe, Pioglitazone Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Terry Chambless, M.D.,P.A. accept Medicare? ▼
Terry Chambless, M.D.,P.A. appears in CMS Medicare data with 6,466 Part D claims and 268 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Terry Chambless, M.D.,P.A.'s credentials? ▼
Terry Chambless, M.D.,P.A.'s NPI is 1831188572 with credentials M.D.,P.A.. 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.
- 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.