2026 NPPES data Sleep Medicine (Internal Medicine) Physician NPI 1316954092 MD, PHD
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SONYA MERRILL, MD, PHD

Sleep Medicine (Internal Medicine) Physician in DALLAS, Texas. 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
321
Medicare Part D claims · 58 beneficiaries · Sleep Medicine (Internal Medicine) Physician avg: 1K
Generic prescribing
76%
generic claims · 24% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$99.99
1 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

SONYA MERRILL, MD, PHD filed 321 Medicare Part D claims in 2023 as a Sleep Medicine (Internal Medicine) Physician in DALLAS, Texas, prescribing 76% generic.

321
Part D claims, 2023
76%
generic prescribing
$99.99
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.

SONYA MERRILL, MD, PHD's Medicare Part D volume vs every U.S. prescriber

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

321 Top 43% higher than 57% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 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

Board-eligible specialty (heuristic — not verified)

SONYA MERRILL, MD, PHD 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 SONYA MERRILL, MD, PHD?

Quality data not reported

NPI registry status

Active

Issued 08/02/2006

NPI 1316954092

Primary specialty

Sleep Medicine (Internal Medicine) Physician

Niche

857 US NPIs in this specialty

Medicare Part D claims

321 75% vs specialty avg

2023 prescription claims

Specialty avg: 1,310

Specialty distribution in Texas

How Sleep Medicine (Internal Medicine) Physician compares to other specialties among Texas providers

Texas providers

Sleep Medicine (Internal Medicine) Physician share within Texas

1. Sleep Medicine (Internal Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Sleep Medicine (Internal Medicine) Physician share within Texas

Specialty board-certification context

Estimated specialty board-certified rate — Sleep Medicine (Internal Medicine) Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Sleep Medicine (Internal Medicine) Physician ABMS/AOA estimate

Est. board-certified rate (Sleep Medicine (Internal Medicine) Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Sleep Medicine (Internal Medicine) Physician) — 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).

SONYA MERRILL, MD, PHD is a Sleep Medicine (Internal Medicine) Physician provider practicing in DALLAS, Texas, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD, PHD. NPI: 1316954092. 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.

SONYA MERRILL, MD, PHD appears in the CMS NPPES registry as a Sleep Medicine (Internal Medicine) Physician provider holding MD, PHD credentials at 7777 FOREST LN, DALLAS, TX, 75230, with a listed phone of (972) 566-7684. NPI 1316954092 was issued on 08/02/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MERRILL 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 321 prescription claims written by this provider, covering 58 Medicare beneficiaries and totaling roughly $36K 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.

Sleep Medicine (Internal Medicine) Physician is a narrow specialty nationwide, with 857 enrolled providers across 52 states and an average of 1,310 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

7777 FOREST LN
DALLAS, TX 75230

Provider Details

NPI 1316954092
Specialty Sleep Medicine (Internal Medicine) Physician
Credentials MD, PHD
Gender Female
NPI Issued 08/02/2006

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 SONYA MERRILL, MD, PHD. Source: openpaymentsdata.cms.gov.

Total received

$100

Largest payer

HARMONY BIOSCIENCES LLC

Most common payment type

Education

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 SONYA MERRILL, MD, PHD. To verify SONYA MERRILL, MD, PHD'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

SONYA MERRILL, MD, PHD — brand share 24.0%
Specialty average (est.)

24% brand-name claims vs 76% generic, on 321 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.

321
Total Claims
$36K
Total Drug Cost
58
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
450
Total Day Supply
13,440
Brand vs Generic
24% brand / 76% generic
Brand Drug Cost
$22K
Generic Drug Cost
$14K

Patient Demographics

Average Patient Age
73.0 years
Avg HCC Risk Score
1.10
Gender Split
50% female / 50% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Doxepin Hcl
77
Gabapentin
63
Eszopiclone
56
Horizant
Gabapentin Enacarbil
18
Armodafinil
17
Zaleplon
14
Zolpidem Tartrate
14
Pramipexole Dihydrochloride
Pramipexole Di-Hcl
13
Trazodone Hcl
13

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

Sleep Medicine (Internal Medicine) Physician Overview

How SONYA MERRILL, MD, PHD fits within the Sleep Medicine (Internal Medicine) Physician landscape nationally.

857
Sleep Medicine (Internal Medicine) Physician Providers in US
52
States with Sleep Medicine (Internal Medicine) Physician
1,310
Avg Claims per Provider

SONYA MERRILL, MD, PHD's 321 claims are below the specialty average of 1,310.

Nearby Sleep Medicine (Internal Medicine) Physician Providers in Texas

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

Compare Sleep Medicine (Internal Medicine) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is SONYA MERRILL, MD, PHD's specialty?
SONYA MERRILL, MD, PHD specializes in Sleep Medicine (Internal Medicine) Physician and practices in DALLAS, Texas. Credentials: MD, PHD.
How much does SONYA MERRILL, MD, PHD prescribe under Medicare Part D?
In 2023, SONYA MERRILL, MD, PHD wrote 321 Medicare Part D claims totaling $36K in drug costs for 58 beneficiaries.
Where is SONYA MERRILL, MD, PHD located?
SONYA MERRILL, MD, PHD is located at 7777 FOREST LN, DALLAS, TX, 75230. Phone: (972) 566-7684.
What is SONYA MERRILL, MD, PHD's NPI number?
SONYA MERRILL, MD, PHD's National Provider Identifier (NPI) is 1316954092, issued on 08/02/2006.
Does SONYA MERRILL, MD, PHD prescribe more brand-name or generic drugs?
SONYA MERRILL, MD, PHD's prescribing is 24% brand-name and 76% generic drugs by claim count, with $22K in brand drug costs.
How many Sleep Medicine (Internal Medicine) Physician providers are there in the US?
There are 857 Sleep Medicine (Internal Medicine) Physician providers across 52 states in the US. The average Sleep Medicine (Internal Medicine) Physician provider writes 1,310 Medicare Part D claims per year.
What drugs does SONYA MERRILL, MD, PHD prescribe most often?
Based on 2023 Medicare Part D data, SONYA MERRILL, MD, PHD's most frequently prescribed drugs include Doxepin Hcl, Gabapentin, Eszopiclone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does SONYA MERRILL, MD, PHD accept Medicare?
SONYA MERRILL, MD, PHD appears in CMS Medicare data with 321 Part D claims and 58 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify SONYA MERRILL, MD, PHD's credentials?
SONYA MERRILL, MD, PHD's NPI is 1316954092 with credentials MD, PHD. 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