NPI registry status
Active
2026 NPPES data Family Medicine Physician NPI 1629234489 M.D.
Verify on CMS → Grace Stonerock, M.D.
Family Medicine Physician in Manassas, Virginia.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 147,760 in Family 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
7K
Medicare Part D claims · 401 beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
86%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
21.6/100
▼ 62 pts below national avg 83.5 · Below average
Industry payments
$3.0K
168 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Grace Stonerock, M.D. reported a CMS MIPS final score of 21.6/100 - below the 83.5 national average - and filed 6,983 Medicare Part D claims in 2023.
- 21.6/100
- MIPS score · -62 vs avg
- 7K
- Part D claims, 2023
- 86%
- 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.
Grace Stonerock, M.D.'s MIPS score vs every measured U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure. Clinicians whose score CMS assigned without scoring any category are excluded.
22 ≥ 3rd percentile 3% of 454,083 measured providers are in lower value bands
Each bar is a band; taller bars hold more measured 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.
The percentile is a conservative whole-score-point band: it counts only measured clinicians in lower score bands. A CMS MIPS metric is not a recommendation or a clinical-quality rating by PlainDoctor. See methodology § corpus placement.
Source CMS Merit-based Incentive Payment System (MIPS) · 2023
Where Grace Stonerock, M.D. sits
This provider among family medicine physician peers
Across the 21,266 family medicine physician providers who report both Medicare Part D prescribing and a MIPS quality score, Grace Stonerock, M.D. writes more Part D claims than 78% of them and scores higher on MIPS quality than 3% - 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
Each dot is one family medicine physician peer from a representative sample of 60; the gold marker is Grace Stonerock, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
✓
Board certification likely (heuristic, not verified)
Grace Stonerock, 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 Grace Stonerock, M.D.?
Below national averagePrimary specialty
Family Medicine Physician
Medicare Part D claims
6,983 104% vs specialty avg
MIPS final score
21.6/100 61.9 pts vs avg
Specialty distribution in Virginia
How Family Medicine Physician compares to other specialties among Virginia providers
Medicare quality performance, MIPS
Grace Stonerock, M.D.'s 2023 MIPS final score plotted against the Family Medicine Physician national average
- MIPS Final Score
- 21.6/100
- vs 83.5 national avg · 2023 performance year
MIPS final score (Family Medicine Physician) - 21.6/100 vs national avg 83.5
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).
Grace Stonerock, M.D. appears in the CMS NPPES registry as a Family Medicine Physician provider holding M.D. credentials at 10696 CRESTWOOD DR STE B, Manassas, VA, 20109, with a listed phone of (703) 368-7110. NPI 1629234489 was issued on 07/31/2008.
Medicare Part D records for calendar year 2023 show 6,983 prescription claims written by this provider, covering 401 Medicare beneficiaries and totaling roughly $801K in drug spend, split 12% brand-name and 86% generic by claim count, with an opioid prescribing rate of 1.8%. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 21.6/100 for the 2023 performance year (Quality 0, Cost 72.1), compared with the 83.5 average among clinicians with a measured score.
Family Medicine Physician is a high-volume specialty nationwide, with 147,760 enrolled providers across 56 states and an average of 3,418 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 | 1629234489 |
|---|---|
| Specialty | Family Medicine Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 07/31/2008 |
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
21.6172
Final Score
Measured-score avg: 83.5
0
Quality
72.0573
Cost
Reporting: Individual
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 Grace Stonerock, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$3.0K
Largest payer
AstraZeneca Pharmaceuticals LP
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
Grace Stonerock, M.D. - brand share 12.0%
Family Medicine Physician average
12% brand-name claims vs 86% generic, on 6,983 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.
6,983
Total Claims
$801K
Total Drug Cost
401
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 15,632
- Total Day Supply
- 454,186
- Brand vs Generic
- 12% brand / 86% generic
- Brand Drug Cost
- $663K
- Generic Drug Cost
- $134K
- Opioid Claims
- 124 (1.8% rate)
- Antibiotic Claims
- 250
Patient Demographics
- Average Patient Age
- 71.2 years
- Avg HCC Risk Score
- 0.87
- Gender Split
- 71% female / 29% male
- Age Distribution
- <65: 47, 65-74: 209, 75-84: 118, 85+: 27
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Grace Stonerock, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Amlodipine Besylate
Amlodipine Besylate
328 claims
- Atorvastatin Calcium
Atorvastatin Calcium
322 claims
- Levothyroxine Sodium
Levothyroxine Sodium
283 claims
- Metformin Hcl
Metformin Hcl
218 claims
- Pravastatin Sodium
Pravastatin Sodium
214 claims
- Montelukast Sodium
Montelukast Sodium
212 claims
- Lisinopril
Lisinopril
192 claims
- Gabapentin
Gabapentin
138 claims
| Drug | Claims |
|---|---|
| Amlodipine Besylate | 328 |
| Atorvastatin Calcium | 322 |
| Levothyroxine Sodium | 283 |
| Metformin Hcl | 218 |
| Pravastatin Sodium | 214 |
| Montelukast Sodium | 212 |
| Lisinopril | 192 |
| Gabapentin | 138 |
| Alprazolam | 136 |
| Trazodone Hcl | 135 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Family Medicine Physician Overview
How Grace Stonerock, M.D. fits within the Family Medicine Physician landscape nationally.
147,760
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider
Grace Stonerock, M.D.'s 6,983 claims are above the specialty average of 3,418.
Nearby Family Medicine Physician Providers in Virginia
Other clinicians with the same primary specialty enrolled in Virginia, drawn from the same CMS NPPES roster as Stonerock.
Dr. Maureen Aaron
M.D.
Martinsville, VA
Dr. Marianne Abadam
DO
Hampton, VA
Dr. Linda Abbey
M.D.
Richmond, VA
Dr. David Abbot
MD
Vienna, VA
Dr. James Abbott
M.D.
Richmond, VA
Compare Family 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 Virginia medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Family 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 Grace Stonerock, M.D.'s specialty? ▼
Grace Stonerock, M.D. specializes in Family Medicine Physician and practices in Manassas, Virginia. Credentials: M.D..
How much does Grace Stonerock, M.D. prescribe under Medicare Part D? ▼
In 2023, Grace Stonerock, M.D. wrote 6,983 Medicare Part D claims totaling $801K in drug costs for 401 beneficiaries.
What is Grace Stonerock, M.D.'s Medicare quality score? ▼
Grace Stonerock, M.D. has a CMS MIPS Final Score of 21.6/100 (Quality: 0, Cost: 72.1). The average MIPS Final Score across the 454,083 clinicians with at least one published category score is 83.5; clinicians whose score CMS assigned without scoring any category are excluded from that average. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Grace Stonerock, M.D. located? ▼
Grace Stonerock, M.D. is located at 10696 CRESTWOOD DR STE B, Manassas, VA, 20109. Phone: (703) 368-7110.
What is Grace Stonerock, M.D.'s NPI number? ▼
Grace Stonerock, M.D.'s National Provider Identifier (NPI) is 1629234489, issued on 07/31/2008.
Does Grace Stonerock, M.D. prescribe more brand-name or generic drugs? ▼
Grace Stonerock, M.D.'s prescribing is 12% brand-name and 86% generic drugs by claim count, with $663K in brand drug costs.
Does Grace Stonerock, M.D. prescribe opioids? ▼
Yes, Grace Stonerock, M.D. had 124 opioid claims in 2023 with an opioid prescribing rate of 1.8%.
How many Family Medicine Physician providers are there in the US? ▼
There are 147,760 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does Grace Stonerock, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Grace Stonerock, M.D.'s most frequently prescribed drugs include Amlodipine Besylate, Atorvastatin Calcium, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Grace Stonerock, M.D. accept Medicare? ▼
Grace Stonerock, M.D. appears in CMS Medicare data with 6,983 Part D claims and 401 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Grace Stonerock, M.D.'s credentials? ▼
Grace Stonerock, M.D.'s NPI is 1629234489 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
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.