---
schema_version: "secwatch.filing_event.v1"
accession: "0001466593-26-000034"
form_type: "8-K"
ticker: "OTTR"
cik: "0001466593"
company_name: "Otter Tail Corp"
filed_at: "2026-03-23T23:59:59+00:00"
generated_at: "2026-05-15T09:21:22.235101+00:00"
event_type: "debt"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Otter Tail Power issues $170M senior unsecured notes (5.33% and 6.04%)

## Summary
- Issued $100M 5.33% Series 2026A Notes due 2036 and $70M 6.04% Series 2026B Notes due 2056.
- Series 2026A closed March 19, 2026; Series 2026B expected to close June 4, 2026.
- Proceeds to fund capital expenditures, refinance existing debt, and for general corporate purposes.
- Covenants limit Interest-bearing Debt to 65% of Total Capitalization and Priority Indebtedness to 20%.

## SEC filing metadata
- accession: 0001466593-26-000034
- form_type: 8-K
- ticker: OTTR
- cik: 0001466593
- company_name: Otter Tail Corp
- filed_at: 2026-03-23T23:59:59+00:00
- event_type: debt
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 1.01, 2.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1466593/000146659326000034/0001466593-26-000034-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1466593/000146659326000034/ottr-20260319.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001466593-26-000034
- JSON: https://secwatch.observer/filing/0001466593-26-000034.json
- Plain text: https://secwatch.observer/filing/0001466593-26-000034.txt

## Source-grounded claims
- claim_id: c344764b329530a9d8f57abadce130ab284b49a5
  claim: Otter Tail Corp incurred senior notes of $170,000,000 aggregate principal amount of the Company’s senior unsecured notes consisting of $100,000,000 in aggregate with the purchasers named therein at 5.33% and 6.04% maturing March 19, 2036 and June 4, 2056.
  evidence_excerpt: (the “Note Purchase Agreement”) with the purchasers named therein (the “Purchasers”), pursuant to which the Company issued to the Purchasers, in a private placement transaction, $170,000,000 aggregate principal amount of the Company’s senior unsecured notes consisting of $100,000,000 in aggregate principal amount of its 5.33% Series 2026A Senior Unsecured Notes due
  evidence_url: https://www.sec.gov/Archives/edgar/data/1466593/000146659326000034/0001466593-26-000034-index.htm
- claim_id: 5c7a74afdb5824a5e41eeb38aa9f680fe1bbd1e2
  claim: Otter Tail Corp entered into Note Purchase Agreement with the purchasers named therein (the ‘Purchasers’) valued at $170,000,000 aggregate principal amount (effective 2026-03-19).
  evidence_excerpt: On March 19, 2026, Otter Tail Power Company (the “Company”), a wholly owned subsidiary of Otter Tail Corporation (“OTC”), entered into a Note Purchase Agreement (the “Note Purchase Agreement”) with the purchasers named therein (the “Purchasers”), pursuant to which the Company issued to the Purchasers, in a private placement transaction, $170,000,000 aggregate principal amount of the Company’s senior unsecured notes consisting of $100,000,000 in aggregate principal amount of its 5.33% Series 2026A Senior Unsecured Notes due March 19, 2036 (the “Series 2026A Notes”) and $70,000,000 in aggregate principal amount of its 6.04% Series 2026B Senior Unsecured Notes due June 4, 2056 (the “Series 2026B Notes”) (collectively, the “Notes”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1466593/000146659326000034/0001466593-26-000034-index.htm

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