---
schema_version: "secwatch.filing_event.v1"
accession: "0001877939-25-000044"
form_type: "8-K"
ticker: "CTM"
cik: "0001877939"
company_name: "Castellum, Inc."
filed_at: "2025-04-21T23:59:59+00:00"
generated_at: "2026-05-23T10:39:14.190984+00:00"
event_type: "debt"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Castellum reduces $2M of principal on Eisiminger notes, extends maturity to Dec 2027, rate to 10%

## Summary
- $2M principal payment reduces two notes to $4M aggregate; $400k note paid off, $5.6M note now $4M.
- Maturity on remaining note extended from Aug 2026 to Dec 15, 2027.
- Interest rate on the $4M note increased from 8% to 10% per annum.
- Amended letter agreement with Robert Eisiminger effective April 17, 2025.
- CFO cites de-levering balance sheet; CEO says it fortifies organic growth strategy.

## SEC filing metadata
- accession: 0001877939-25-000044
- form_type: 8-K
- ticker: CTM
- cik: 0001877939
- company_name: Castellum, Inc.
- filed_at: 2025-04-21T23:59:59+00:00
- event_type: debt
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 1.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1877939/000187793925000044/0001877939-25-000044-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1877939/000187793925000044/ctm-20250417.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001877939-25-000044
- JSON: https://secwatch.observer/filing/0001877939-25-000044.json
- Plain text: https://secwatch.observer/filing/0001877939-25-000044.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.