Doctor profile · Federal record

Dr. Gwendolen Chang, M.D.

Internal Medicine Physician (CMS: Nephrology) · San Leandro, CA

  • NPI 1386807402
  • Accepts Medicare
  • 19 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
13851 E 14Th St Ste 206
San Leandro, CA 945782627
(510) 351-9373
fax (510) 351-0616

Credentials & registration

NPPES · NUCC
NPI registered
July 2008 — 18 yrs on file
Profile last updated
December 4, 2013
Year of graduation
2007 — 19 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A106132

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1386807402. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,785
Distinct HCPCS
10
Medicare allowed
$326,224
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 436 130 $128
99214 Established patient office or other outpatient visit, 30-39 minutes 376 168 $134
90960 Dialysis services, 4 or more physician visits per month (20 years or older) 301 38 $406
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 242 99 $87
90935 Hemodialysis procedure with physician evaluation 117 71 $79
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 74 71 $194
90961 Dialysis services, 2-3 physician visits per month (20 years or older) 52 20 $339
99204 New patient office or other outpatient visit, 45-59 minutes 46 46 $197
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 46 42 $147
99215 Established patient office or other outpatient visit, 40-54 minutes 41 28 $189

In context: peer comparison

Among 15 peers in San Leandro Internal Medicine Physician, average services per provider: 94. This provider delivers 19× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$1,284
Transactions
52
Manufacturers
15
Payer (manufacturer) Industry Txns Amount
Novartis Pharmaceuticals Corporation 10 $248.59
Amgen INC. 8 $217.16
Fresenius USA Marketing, INC. 8 $162.48
Otsuka America Pharmaceutical, INC. 6 $151.72
Ardelyx, INC. 3 $86.11
Vifor Pharma, INC. 3 $82.87
Bayer Healthcare Pharmaceuticals INC. 2 $64.10
Opko Pharmaceuticals, LLC 3 $52.10
Aurinia Pharma U.S., INC. 2 $48.79
Novo Nordisk INC 2 $34.50
Travere Therapeutics, INC. 1 $27.13
Mallinckrodt Hospital Products INC. 1 $26.04
Calliditas Therapeutics US INC. 1 $25.52
Lilly USA, LLC 1 $24.43
AstraZeneca Pharmaceuticals Lp 1 $18.88

By nature of payment

Food and Beverage
$1,212
Education
$72

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
1,036
Patients
229
Total drug cost
$230,049
Drug Type Claims Patients Total cost
Amlodipine Besylate Generic 172 56 $3,091
Allopurinol Generic 128 37 $2,291
Furosemide Generic 125 31 $1,160
Bumetanide Generic 99 24 $4,845
Losartan Potassium Generic 83 27 $1,500
Lisinopril Generic 78 25 $1,310
Veltassa (Patiromer Calcium Sorbitex) Brand 54 0 $66,545
Lokelma (Sodium Zirconium Cyclosilicate) Brand 50 0 $49,726
Farxiga (Dapagliflozin Propanediol) Brand 45 13 $37,455
Rayaldee (Calcifediol) Brand 42 0 $58,118

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Gwendolen Chang's medical specialty?
Dr. Gwendolen Chang practices Internal Medicine Physician in San Leandro, CA.
Where does Dr. Gwendolen Chang practice?
Dr. Gwendolen Chang practices at 13851 E 14Th St Ste 206, San Leandro, CA 945782627. Office phone: 5103519373.
What is Dr. Gwendolen Chang's NPI?
Dr. Gwendolen Chang's National Provider Identifier (NPI) is 1386807402, issued by NPPES.
Does Dr. Gwendolen Chang accept Medicare assignment?
Yes. Dr. Gwendolen Chang accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Gwendolen Chang commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Established patient office or other outpatient visit (HCPCS 99214); Dialysis services, 4 or more physician visits per month (20 years or older) (HCPCS 90960). Source: CMS Medicare Physician & Other Practitioners file.