NPI registry status
Active
2026 NPPES data Family Medicine Physician NPI 1336378819 M.D.
Verify on CMS → Amber McIlwain, M.D.
Family Medicine Physician in Diamondhead, Mississippi.
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
3K
Medicare Part D claims · 309 beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
84%
generic claims · 14% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Amber McIlwain, M.D. filed 3,460 Medicare Part D claims in 2023 as a Family Medicine Physician in Diamondhead, Mississippi, prescribing 84% generic.
- 3K
- Part D claims, 2023
- 84%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥90th
- pct by Part D claim volume (lower-bound band)
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.
Amber McIlwain, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
3,460 ≥ 90th percentile 90% of 1,370,886 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
Amber McIlwain, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - 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 Amber McIlwain, M.D.?
Quality data not reportedPrimary specialty
Family Medicine Physician
Medicare Part D claims
3,460 1% vs specialty avg
Specialty distribution in Mississippi
How Family Medicine Physician compares to other specialties among Mississippi 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 Family 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).
Amber McIlwain, M.D. appears in the CMS NPPES registry as a Family Medicine Physician provider holding M.D. credentials at 4540 SHEPHERD SQ, Diamondhead, MS, 39525, with a listed phone of (228) 255-8216. NPI 1336378819 was issued on 07/06/2009.
Medicare Part D records for calendar year 2023 show 3,460 prescription claims written by this provider, covering 309 Medicare beneficiaries and totaling roughly $508K in drug spend, split 14% brand-name and 84% generic by claim count, with an opioid prescribing rate of 3.2%.
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 | 1336378819 |
|---|---|
| Specialty | Family Medicine Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 07/06/2009 |
Hospital and facility affiliations
Facilities where Amber McIlwain, 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.
Ochsner Mississippi, LLC
Diamondhead, MS
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Typical
Amber McIlwain, M.D. - brand share 14.0%
Family Medicine Physician average
14% brand-name claims vs 84% generic, on 3,460 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.
3,460
Total Claims
$508K
Total Drug Cost
309
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 7,700
- Total Day Supply
- 222,689
- Brand vs Generic
- 14% brand / 84% generic
- Brand Drug Cost
- $446K
- Generic Drug Cost
- $59K
- Opioid Claims
- 112 (3.2% rate)
- Antibiotic Claims
- 84
Patient Demographics
- Average Patient Age
- 68.0 years
- Avg HCC Risk Score
- 1.10
- Gender Split
- 69% female / 31% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Amber McIlwain, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Levothyroxine Sodium
Levothyroxine Sodium
114 claims
- Lisinopril
Lisinopril
110 claims
- Atorvastatin Calcium
Atorvastatin Calcium
99 claims
- Rosuvastatin Calcium
Rosuvastatin Calcium
99 claims
- Amlodipine Besylate
Amlodipine Besylate
97 claims
- Ozempic
Ozempic
82 claims
- Pantoprazole Sodium
Pantoprazole Sodium
81 claims
- Losartan Potassium
Losartan Potassium
76 claims
| Drug | Claims |
|---|---|
| Levothyroxine Sodium | 114 |
| Lisinopril | 110 |
| Atorvastatin Calcium | 99 |
| Rosuvastatin Calcium | 99 |
| Amlodipine Besylate | 97 |
| Ozempic Semaglutide | 82 |
| Pantoprazole Sodium | 81 |
| Losartan Potassium | 76 |
| Gabapentin | 71 |
| Omeprazole | 66 |
* 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 Amber McIlwain, 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
Amber McIlwain, M.D.'s 3,460 claims are above the specialty average of 3,418.
Nearby Family Medicine Physician Providers in Mississippi
Other clinicians with the same primary specialty enrolled in Mississippi, drawn from the same CMS NPPES roster as McIlwain.
One of 1,113 Family Medicine Physician providers enrolled in Mississippi, 5 are shown here.
Dr. Rolando Abangan
M.D.
Meridian, MS
Dr. Abdu Mohamed Abdallah Ahmed
MD
Jackson, MS
Dr. Kevin Abel
M.D.
Baldwyn, MS
Dr. George Abraham
MD
Vicksburg, MS
Dr. Audie Adams
M.D.
Senatobia, MS
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 Mississippi 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 Amber McIlwain, M.D.'s specialty? ▼
Amber McIlwain, M.D. specializes in Family Medicine Physician and practices in Diamondhead, Mississippi. Credentials: M.D..
How much does Amber McIlwain, M.D. prescribe under Medicare Part D? ▼
In 2023, Amber McIlwain, M.D. wrote 3,460 Medicare Part D claims totaling $508K in drug costs for 309 beneficiaries.
Where is Amber McIlwain, M.D. located? ▼
Amber McIlwain, M.D. is located at 4540 SHEPHERD SQ, Diamondhead, MS, 39525. Phone: (228) 255-8216.
What is Amber McIlwain, M.D.'s NPI number? ▼
Amber McIlwain, M.D.'s National Provider Identifier (NPI) is 1336378819, issued on 07/06/2009.
Does Amber McIlwain, M.D. prescribe more brand-name or generic drugs? ▼
Amber McIlwain, M.D.'s prescribing is 14% brand-name and 84% generic drugs by claim count, with $446K in brand drug costs.
Does Amber McIlwain, M.D. prescribe opioids? ▼
Yes, Amber McIlwain, M.D. had 112 opioid claims in 2023 with an opioid prescribing rate of 3.2%.
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 Amber McIlwain, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Amber McIlwain, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Lisinopril, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Amber McIlwain, M.D. accept Medicare? ▼
Amber McIlwain, M.D. appears in CMS Medicare data with 3,460 Part D claims and 309 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Amber McIlwain, M.D.'s credentials? ▼
Amber McIlwain, M.D.'s NPI is 1336378819 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.
- 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.