Official source Data mirrored from Centers for Medicare & Medicaid Services Open Payments · General Payments · as published 2026-01-23 View official record Methodology

Covered recipient · General Payments record

CHESTER D ZAHN

Allopathic & Osteopathic Physicians Internal Medicine Gastroenterology

NPI
1639146442
CMS profile
28453
Location
SAN GABRIEL, CA

General Payments · PY2018–2024

$1,252.97

  • Reported across 77 records
  • CMS publication 2026-01-23

Latest program year · PY2024

$296.06

17 records · 0 disputed

Financial relationships do not necessarily indicate an improper relationship; the data is open to interpretation.

How these totals are calculated
  • The total is the sum of the General Payments records CMS published for the labeled program year(s), exactly as published. Nothing is estimated, weighted, or combined across categories.
  • General Payments only. Research and Ownership/Investment are separate datasets and are never summed with these figures; amounts are kept separate per program year.
  • Featured-page threshold (a presentation gate, not a judgment): records>=3 OR total>=100 (all years).
  • Methodology & Data — sourcing, labeling, and limitations.

By nature of payment

PY2024 · sorted by reported total

Nature of paymentAmountRecords
Food and Beverage $264.48 15
Education $31.58 2

By paying entity

PY2024 · sorted by reported total

Paying entityAmountRecords
Gilead Sciences, Inc. $194.61 13
ABBVIE INC. $30.37 1
Janssen Biotech, Inc. $24.93 1
ALBIREO PHARMA, INC. $23.33 1
Phathom Pharmaceuticals, Inc. $22.82 1

By program year

All program years on this page · sorted by year

Program yearAmountRecords
PY2018 $141.94 8
PY2019 $228.54 20
PY2020 $219.79 14
PY2021 $119.81 6
PY2022 $104.62 5
PY2023 $142.21 7
PY2024 $296.06 17

Payment records · PY2024 (17)

Sorted by paying entity, then date · as published by CMS

Program year 2024 201820192020202120222023 Record-level detail is published for PY2024; earlier years are summarised in “By program year”.
Paying entity Amount Date Nature of payment Dispute status Published Record ID Source
ABBVIE INC. $30.37 05/06/2024 Food and Beverage Undisputed 01/23/2026 1106387882 CMS
ALBIREO PHARMA, INC. $23.33 08/05/2024 Food and Beverage Undisputed 01/23/2026 1071126898 CMS
Gilead Sciences, Inc. $3.31 02/05/2024 Food and Beverage Undisputed 01/23/2026 1133791241 CMS
Gilead Sciences, Inc. $13.51 02/05/2024 Food and Beverage Undisputed 01/23/2026 1133791243 CMS
Gilead Sciences, Inc. $19.85 03/28/2024 Food and Beverage Undisputed 01/23/2026 1133791245 CMS
Gilead Sciences, Inc. $20.60 03/28/2024 Food and Beverage Undisputed 01/23/2026 1133791247 CMS
Gilead Sciences, Inc. $15.97 06/05/2024 Food and Beverage Undisputed 01/23/2026 1133791249 CMS
Gilead Sciences, Inc. $15.64 07/10/2024 Food and Beverage Undisputed 01/23/2026 1133791251 CMS
Gilead Sciences, Inc. $20.35 07/10/2024 Food and Beverage Undisputed 01/23/2026 1133791253 CMS
Gilead Sciences, Inc. $11.00 08/21/2024 Food and Beverage Undisputed 01/23/2026 1133791255 CMS
Gilead Sciences, Inc. $19.99 08/23/2024 Education Undisputed 01/23/2026 1133891113 CMS
Gilead Sciences, Inc. $24.25 09/11/2024 Food and Beverage Undisputed 01/23/2026 1133791257 CMS
Gilead Sciences, Inc. $11.59 09/11/2024 Education Undisputed 01/23/2026 1133891115 CMS
Gilead Sciences, Inc. $15.28 10/23/2024 Food and Beverage Undisputed 01/23/2026 1133791259 CMS
Gilead Sciences, Inc. $3.27 11/20/2024 Food and Beverage Undisputed 01/23/2026 1133791261 CMS
Janssen Biotech, Inc. $24.93 10/09/2024 Food and Beverage Undisputed 01/23/2026 1078332893 CMS
Phathom Pharmaceuticals, Inc. $22.82 03/06/2024 Food and Beverage Undisputed 01/23/2026 1151142507 CMS

Source & provenance

Dataset
CMS Open Payments — General Payments
Publisher of source data
Centers for Medicare & Medicaid Services
CMS publication date
2026-01-23
Program years on this page
2018, 2019, 2020, 2021, 2022, 2023, 2024
Source files
Dataset page · Bulk file · PY2018 , PY2019 , PY2020 , PY2021 , PY2022 , PY2023 , PY2024
Generated from
OP_DTL_GNRL_PGYR2024_P01232026_01102026.csv

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