If you want to cut through a campaign's rhetoric and see who is actually writing the checks, the single highest-signal field in the FEC individual-contribution file is the five-digit ZIP code. Combine it with the donor's itemized amount, and you get a surprisingly sharp picture of the campaign's geographic coalition.
On LobbyVault, the /zip-codes/ index ranks ZIPs by total dollars contributed to federal candidates and committees. The individual ZIP detail pages (e.g. /zip-codes/10011/) drill into:
- Top recipient candidates — where the ZIP's money actually lands.
- Top recipient committees — which PACs and super PACs the ZIP funds.
- Party split — the share going to D vs R vs other.
- Top employers and occupations — who lives and works there.
The donor ZIPs that actually matter
A handful of ZIPs punch far above their weight. The recurring heavyweights are:
- 10021 / 10075 / 10028 (Upper East Side, New York) — Wall Street finance donors on both sides of the aisle.
- 10011 / 10014 (West Village / Chelsea, New York) — heavily Democratic individual-donor ZIPs.
- 94027 (Atherton, CA) and 94301 (Palo Alto, CA) — Silicon Valley tech money.
- 90210 / 90402 (Beverly Hills / Santa Monica) — entertainment and legal.
- 20016 / 20015 (NW Washington, DC) — the "inside the Beltway" donor corridor.
- 33480 (Palm Beach, FL) — right-leaning finance and real-estate donors.
- 02138 (Cambridge, MA) — academic / nonprofit Democratic donors.
If you see a campaign's top 20 donor ZIPs dominated by these codes, you're looking at a nationally-networked fundraising operation, not a grassroots one.
What a "local" campaign's ZIPs look like
Contrast a House challenger running a genuinely local campaign. Their top ZIPs will be:
- Their home district.
- Adjacent suburban ZIPs that share their media market.
- Maybe one or two in their home state capital, if they have state-level political roots.
That geographic tightness is itself a signal — for viability (tight-coalition candidates often lose primaries to better-networked ones) and for policy (a candidate funded by their own neighbors votes differently than one funded by a national donor network).
Where ZIP data misleads
A few traps to avoid when you read ZIP-level donor data:
- Address of record vs address of residence. High-net-worth donors often list a secondary address (Florida or Wyoming, for tax reasons) on FEC filings. The ZIP is where they sent the check from, not necessarily where they live most of the year.
- Corporate HQ ZIPs. Some donors list their office address. A cluster of donations from 10020 (Rockefeller Center) probably reflects several people who all work at Comcast/NBCU, not a neighborhood donor surge.
- The 20001-20024 DC range is disproportionately lobbyists, trade-association staff, and federal employees. DC ZIP dollars are almost always a signal about Washington's interest in a race, not a candidate's home-district strength.
Practical reading
Here is the workflow I run when I open a candidate detail page on LobbyVault:
- Check the individual vs PAC ratio. If < 60% individual, the campaign is running on institutional money.
- Look at top ZIPs. Are they local, or are they a national donor-network pattern?
- Cross-reference top industries and top employers. A candidate with "Wall Street finance" as a top industry and 10021 as a top ZIP is telling you exactly who they will take calls from.
- Check top city on the candidate page. If the top city isn't in the candidate's home state, write down whose campaign it actually is.
ZIPs on their own are a blunt instrument, but combined with employer, occupation, and recipient data, they are the fastest way to read a campaign's real coalition without wading through thousands of individual filings.