2026 NPPES data General Practice Physician NPI 1427673821 MD
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MILLICENT HORN, MD

General Practice Physician in SAINT LOUIS, Missouri. 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
679
Medicare Part D claims · 85 beneficiaries · General Practice Physician avg: 3K
Generic prescribing
84%
generic claims · 16% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
79.292/100
▼ 4 pts below national avg 83.1 · [object Object]
What the federal data reveals: MILLICENT HORN, MD is a General Practice Physician ([object Object]) practicing in SAINT LOUIS, Missouri with a Medicare Part D prescribing footprint of 679 claims across 85 beneficiaries — 16% brand-name prescribing . Their CMS MIPS Final Score of 79.292/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities .

What stands out: MILLICENT HORN, MD reported a CMS MIPS final score of 79.292 out of 100, below the 83.1 national average, and filed 679 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

MILLICENT HORN, MD 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).

MILLICENT HORN, MD at a glance

Near national average

NPI registry status

Active

Issued 06/11/2020

NPI 1427673821

Primary specialty

General Practice Physician

Mid-sized

16,677 US NPIs in this specialty

Medicare Part D claims

679 76% vs specialty avg

2023 prescription claims

Specialty avg: 2,872

MIPS final score

79.292/100 3.8079999999999927% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Missouri

How General Practice Physician compares to other specialties among Missouri providers

Missouri providers

General Practice Physician share within Missouri

1. General Practice Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
General Practice Physician share within Missouri

Medicare quality performance — MIPS

MILLICENT HORN, MD's 2023 MIPS final score plotted against the General Practice Physician national average

Near national average
MIPS Final Score
79.292/100
vs 83.1 national avg · 2023 performance year

MIPS final score (General Practice Physician) — 79.292/100 vs national avg 83.1

0%100%National avg83%79.3%
MIPS final score (General Practice Physician) — 79.292/100 vs national avg 83.1

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).

MILLICENT HORN, MD is a General Practice Physician provider practicing in SAINT LOUIS, Missouri, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1427673821. 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.

MILLICENT HORN, MD appears in the CMS NPPES registry as a General Practice Physician provider holding MD credentials at 4901 FOREST PARK AVE, SAINT LOUIS, MO, 63108, with a listed phone of (314) 362-5060. NPI 1427673821 was issued on 06/11/2020. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HORN 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 679 prescription claims written by this provider, covering 85 Medicare beneficiaries and totaling roughly $91K in drug spend, split 16% brand-name and 84% generic by claim count, with an opioid prescribing rate of 1.9%. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 79.292/100 for the 2023 performance year (Quality 71.46, Cost 59.5132), compared with the national average of 83.1.

General Practice Physician is a mid-sized specialty nationwide, with 16,677 enrolled providers across 56 states and an average of 2,872 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

4901 FOREST PARK AVE
SAINT LOUIS, MO 63108

Provider Details

NPI 1427673821
Specialty General Practice Physician
Credentials MD
Gender Female
NPI Issued 06/11/2020

CMS Quality Score (MIPS)

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

79.292
Final Score
Avg: 83.1
71.46
Quality
59.5132
Cost
100
Promoting Interoperability

Reporting: Group practice

Brand vs generic prescribing mix · Typical

MILLICENT HORN, MD — brand share 16.0%
Specialty average (est.)

16% brand-name claims vs 84% generic, on 679 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.

679
Total Claims
$91K
Total Drug Cost
85
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,252
Total Day Supply
36,782
Brand vs Generic
16% brand / 84% generic
Brand Drug Cost
$83K
Generic Drug Cost
$8K
Opioid Claims
13 (1.9% rate)

Patient Demographics

Average Patient Age
67.8 years
Avg HCC Risk Score
2.43
Gender Split
58% female / 42% male
Age Distribution
<65: 27, 65-74: 40, 75-84: N/A, 85+: N/A

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Atorvastatin Calcium
79
Amlodipine Besylate
71
Lisinopril
35
Gabapentin
29
Metformin Hcl
28
Duloxetine Hcl
26
Pantoprazole Sodium
24
Carvedilol
20
Hydrochlorothiazide
14
Spiriva Handihaler
Tiotropium Bromide
14

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

General Practice Physician Overview

How MILLICENT HORN, MD fits within the General Practice Physician landscape nationally.

16,677
General Practice Physician Providers in US
56
States with General Practice Physician
2,872
Avg Claims per Provider

MILLICENT HORN, MD's 679 claims are below the specialty average of 2,872.

Nearby General Practice Physician Providers in Missouri

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

Compare General Practice Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is MILLICENT HORN, MD's specialty?
MILLICENT HORN, MD specializes in General Practice Physician and practices in SAINT LOUIS, Missouri. Credentials: MD.
How much does MILLICENT HORN, MD prescribe under Medicare Part D?
In 2023, MILLICENT HORN, MD wrote 679 Medicare Part D claims totaling $91K in drug costs for 85 beneficiaries.
What is MILLICENT HORN, MD's Medicare quality score?
MILLICENT HORN, MD has a CMS MIPS Final Score of 79.292/100 (Quality: 71.46, Cost: 59.5132). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is MILLICENT HORN, MD located?
MILLICENT HORN, MD is located at 4901 FOREST PARK AVE, SAINT LOUIS, MO, 63108. Phone: (314) 362-5060.
What is MILLICENT HORN, MD's NPI number?
MILLICENT HORN, MD's National Provider Identifier (NPI) is 1427673821, issued on 06/11/2020.
Does MILLICENT HORN, MD prescribe more brand-name or generic drugs?
MILLICENT HORN, MD's prescribing is 16% brand-name and 84% generic drugs by claim count, with $83K in brand drug costs.
Does MILLICENT HORN, MD prescribe opioids?
Yes, MILLICENT HORN, MD had 13 opioid claims in 2023 with an opioid prescribing rate of 1.9%.
How many General Practice Physician providers are there in the US?
There are 16,677 General Practice Physician providers across 56 states in the US. The average General Practice Physician provider writes 2,872 Medicare Part D claims per year.
What drugs does MILLICENT HORN, MD prescribe most often?
Based on 2023 Medicare Part D data, MILLICENT HORN, MD's most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MILLICENT HORN, MD accept Medicare?
MILLICENT HORN, MD appears in CMS Medicare data with 679 Part D claims and 85 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MILLICENT HORN, MD's credentials?
MILLICENT HORN, MD's NPI is 1427673821 with credentials MD. 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.
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