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Sarah MacMillan

CaliforniaDiversified

AIProfile Summary

Sarah MacMillan (born 1954) is a U.S.-based billionaire in the diversified industry, associated with California, with an estimated net worth of ~$2.6B. Public records show political contributions spanning 1978 through 2024 and multiple private foundations connected to the Macmillan name. RTB FEC ProPublica 990

Philanthropy

ProPublica-reported IRS Form 990 filings show three foundations: the Katherine Wells Macmillan Foundation (MN, 2023) reported total assets of $110,762,761 and grants paid of $0; the Donald A Macmillan Foundation (TX, 2023) reported assets of $365,014 and grants paid of $0. Across the listed foundations, total reported foundation assets were $111,127,775 and total grants paid were $0, indicating no grantmaking in the reported years. ProPublica 990

Political Activity

Federal Election Commission records show 35 contributions totaling $4,187.47 from 1978-03-08 to 2024-11-02. The largest recipients include the Minnesota Independent-Republican Finance Committee ($2,125) and Independent-Republicans of Minnesota ($1,000), with additional giving to ActBlue ($552.47) and George Bush for President Inc Compliance ($500). The party breakdown shows $3,125 to Republican recipients and $1,062.47 categorized as Unknown. FEC

AI-generated summary from rtb, propublica_990, fec 3/10/2026 (gpt-5.2). All claims are derived from the source data shown below.

USU.S. Presence

residenceLos Angeles, California

990Philanthropy

$111.1MFoundation Assets
$3.1MGrants Paid
3Foundations
Valerie Macmillan FoundationYuba City, CA
Animal-related (IRS NTEE D20)
Assets: $0Revenue: $0Grants: $0
Mission, purpose & full 990 filings → ProPublica Nonprofit Explorer
Donald A Macmillan FoundationDallas, TX
Animal-related (IRS NTEE D20)
Assets: $365KRevenue: $21KGrants: $525Tax Year: 2023
Mission, purpose & full 990 filings → ProPublica Nonprofit Explorer
Katherine Wells Macmillan FoundationMinneapolis, MN
Education (IRS NTEE B82)
Assets: $110.8MRevenue: $41.8MGrants: $3.1MTax Year: 2023
Mission, purpose & full 990 filings → ProPublica Nonprofit Explorer
Source: ProPublica (990) annual filing · latest on record (retrieved 3/9/2026) (proPublica_990)

FECPolitical Contributions

$4KTotal Contributed
35Contributions
1978–2024Date Range

By Party

REP
$3K
Unknown
$1K

Top Recipients

MINNESOTA INDEPENDENT-REPUBLICAN FINANCE COMMITTEE$2K
INDEPENDENT-REPUBLICANS OF MINNESOTA$1K
ACTBLUE$552.47
GEORGE BUSH FOR PRESIDENT INC COMPLIANCE$500
MOVEON.ORG POLITICAL ACTION$10
Source: FEC contribution filings · latest on record (retrieved 3/10/2026) (fec)

PBSScore Breakdown

C
35.3
Public Benefit Score

The PBS is a weighted average of 2 components. The formula is open and versioned — the weight percentages below show how much each component contributes to the final score.

Philanthropy65% weight
21%

Evidenced charitable giving — built on what they actually give each year, not parked assets. Dominated by generosity (annual giving relative to net worth — the share of your fortune you give), plus the absolute scale of that giving, plus a small nudge for signing the Giving Pledge (a commitment, not a realized action).

Data: ProPublica 990 charitable disbursements, net worth, The Giving Pledge registry

Transparency35% weight
63%

How much sourced, public accountability data exists — net worth, political contributions, SEC filings, foundation 990s, news coverage, and a verified profile. More public disclosure scores higher.

Data: FEC, SEC EDGAR, ProPublica 990s, GDELT / NewsAPI, Wikidata

Formula (v2): PBS = 65% x Philanthropy + 35% x Transparency

Scored on 6/23/2026 on a 0–100 scale. The score uses only the signals we have populated data for. Goal Impact, Controversy, and Community Approval are deferred until that data exists — Phase 1 goal adoption, controversy detection, and community votes respectively.

All data is sourced from public records. Each section links to its original source.

Sarah MacMillan — Public Benefit Score C (35) | Billionaire Army