Doctor profile · Federal record

Dr. John Armstrong, MD

Gynecology Physician (CMS: Obstetrics/Gynecology) · Napa, CA

  • NPI 1790875995
  • Accepts Medicare
  • MIPS 75.0 / 100 · 2023
  • 50 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3434 Villa Ln, Suite 360
Napa, CA 94558
(707) 257-4317
fax (707) 257-4319

Credentials & registration

NPPES · NUCC
NPI registered
October 2006 — 20 yrs on file
Profile last updated
July 8, 2007
Year of graduation
1976 — 50 yrs since
Specialty taxonomy
207VG0400X — NUCC code
State license (1)
California #00C378990
Medicaid
CA #ZZR0009F

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1790875995. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,842
Distinct HCPCS
10
Medicare allowed
$186,153
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 462 193 $127
76641 Complete ultrasound scan of 1 breast 181 170 $121
76830 Ultrasound scan of uterus, ovaries, tubes, cervix and pelvic area through vagina 178 156 $142
56820 Exam of external female genitals using an endoscope 174 134 $103
G0444 Annual depression screening, 5 to 15 minutes 151 151 $22
57452 Exam of cervix and upper part of vagina using an endoscope 119 107 $143
99213 Established patient office or other outpatient visit, 20-29 minutes 97 73 $76
99215 Established patient office or other outpatient visit, 40-54 minutes 96 68 $188
Q0091 Screening papanicolaou smear; obtaining, preparing and conveyance of cervical or vaginal smear to laboratory 87 87 $51
G0101 Cervical or vaginal cancer screening; pelvic and clinical breast examination 86 86 $44

In context: peer comparison

Among 1 peers in Napa Gynecology Physician, average services per provider: 115. This provider delivers 16× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$159
Transactions
8
Manufacturers
6
Payer (manufacturer) Industry Txns Amount
Radius Health, INC. 3 $66.83
Pfizer INC. 1 $20.72
Abbvie INC. 1 $20.05
Organon LLC 1 $18.69
Astellas Pharma US INC 1 $17.62
Sumitomo Pharma America, INC. 1 $15.35

By nature of payment

Food and Beverage
$159

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
498
Patients
127
Total drug cost
$159,601
Drug Type Claims Patients Total cost
Estradiol Generic 223 74 $11,317
Progesterone (Progesterone, Micronized) Brand 77 20 $4,358
Tymlos (Abaloparatide) Brand 41 0 $106,481
Terconazole Generic 35 21 $1,505
Premarin (Estrogens, Conjugated) Brand 26 0 $14,777
Estradiol (Twice Weekly) (Estradiol) Brand 20 0 $2,601
Imvexxy (Estradiol) Brand 19 0 $9,092
Yuvafem (Estradiol) Brand 16 0 $2,146
Nitrofurantoin Mono-Macro (Nitrofurantoin Monohyd/M-Cryst) Brand 15 12 $345
Acyclovir Generic 13 0 $95

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. John Armstrong's medical specialty?
Dr. John Armstrong practices Gynecology Physician in Napa, CA.
Where does Dr. John Armstrong practice?
Dr. John Armstrong practices at 3434 Villa Ln, Napa, CA 94558. Office phone: 7072574317.
What is Dr. John Armstrong's NPI?
Dr. John Armstrong's National Provider Identifier (NPI) is 1790875995, issued by NPPES.
Does Dr. John Armstrong accept Medicare assignment?
Yes. Dr. John Armstrong accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. John Armstrong commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Complete ultrasound scan of 1 breast (HCPCS 76641); Ultrasound scan of uterus, ovaries, tubes, cervix and pelvic area through vagina (HCPCS 76830). Source: CMS Medicare Physician & Other Practitioners file.