Montana candidate filing & campaign-finance deadlines
Official 2026 report due dates for Montana state candidates file with Montana Commissioner of Political Practices (COPP).
2 more deadlines follow in this cycle.
Electbase emails you before every deadline — 14, 7, and 2 days out — and stays current as the official schedule changes.
Get deadline remindersIncluded in every Electbase plan · See pricingThis page also covers Montana candidate-filing (ballot access) deadlines for 2027–2028 — the process of becoming a qualified candidate, distinct from the campaign-finance reporting below. Here's how to run for office in Montana: what to file, when, and with whom.
9 report deadlines for the 2026 cycle.
These are the campaign-finance report due dates a Montana state candidate files with Montana Commissioner of Political Practices (COPP) for the 2026 election cycle, stored verbatim from the official schedule. The 2026 primary is Jun 2, 2026.
| Due | Type | Report | Covers |
|---|---|---|---|
| Annual/Year-end | MT 2025 Year-End Report Year-end C-5 covering October 1 – December 31, 2025. |
Oct 1, 2025 – Dec 31, 2025 | |
| Pre-election | MT Pre-Primary Report 1 C-5 covering January 1 – March 15, 2026. |
Jan 1, 2026 – Mar 15, 2026 | |
| Pre-election | MT Pre-Primary Report 2 C-5 covering March 16 – April 15, 2026. |
Mar 16, 2026 – Apr 15, 2026 | |
| Pre-election | MT Pre-Primary Report 3 Last C-5 before the June 2 primary; covers April 16 – May 14, 2026. |
Apr 16, 2026 – May 14, 2026 | |
| Post-election | MT Post-Primary Report C-5 covering May 15 – June 15, 2026 (June 20 is a Saturday — file early). |
May 15, 2026 – Jun 15, 2026 | |
| Periodic | MT Summer Report C-5 covering June 16 – August 15, 2026 (no July report by statute). |
Jun 16, 2026 – Aug 15, 2026 | |
| Pre-election | MT Pre-General Report 1 C-5 covering August 16 – September 15, 2026 (September 20 is a Sunday — file early). |
Aug 16, 2026 – Sep 15, 2026 | |
| Pre-election | MT Pre-General Report 2 Last C-5 before the November 3 general; covers September 16 – October 14, 2026. |
Sep 16, 2026 – Oct 14, 2026 | |
| Post-election | MT Post-General Report Final scheduled C-5; covers October 15 – November 15, 2026. |
Oct 15, 2026 – Nov 15, 2026 |
Shaded rows are deadlines that have already passed.
Good to know
Montana requires a Form C-5 for every reporting period (even a $0 report). Two published due dates fall on a weekend — June 20 (Saturday) and September 20 (Sunday); the campaign-finance statute has no next-business-day extension, so treat the published date as the hard deadline and file on or before the preceding Friday. Event-driven C-7/C-7E 48-hour reports apply for a single contribution or expenditure over $790 (statewide) / $450 (other) in the windows before each election.
Montana candidate-filing deadlines — 2027–2028.
Deadlines to become a qualified candidate for office in Montana — declarations of candidacy, nominating petitions, and related ballot-access filing requirements — compiled from Montana Secretary of State, Elections and Voter Services Division. Distinct from the campaign-finance report deadlines above.
2027
Municipal
Municipal Offices
Filing window: Closes
Candidacy method: Nonpartisan · Deadline type: Nonpartisan filing
Withdrawal deadline: Aug 11, 2027
Files with: Municipal Clerk
Montana Code Annotated Title 13, Chapter 1, Part 4 - Local Government Elections · accessed Jul 13, 2026
Last verified Jul 13, 2026
Filing for Municipal Offices in Statewide (All Montana Municipalities) for the 2027 Montana Municipal General Election (Nov 2, 2027) closes Aug 4, 2027 at 5:00 PM America/Denver. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
School Board
School Board Trustee
Filing window: –
Candidacy method: Nonpartisan · Deadline type: Nonpartisan filing
Withdrawal deadline: Apr 1, 2027
Files with: School District Clerk
Fee: $0
Montana Code Annotated Title 13, Chapter 10, Part 5 - Special Purpose District Elections · accessed Jul 13, 2026
Not yet independently verified
Filing for School Board Trustee in Statewide (All Montana School Districts) for the 2027 Montana School Board Elections (May 4, 2027) closes Mar 25, 2027 at 5:00 PM America/Denver. Opens Dec 10, 2026. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
2028
Federal
President of the United States
Filing window: –
Candidacy method: Party Primary · Deadline type: Party primary filing
Withdrawal deadline: Mar 20, 2028
Files with: Montana Secretary of State
Fee: $0 (presidential candidates file through party processes)
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration for Nomination · accessed Jul 13, 2026
Not yet independently verified
Filing for President of the United States in Statewide for the 2028 Montana Primary Election (Jun 6, 2028) closes Mar 8, 2028 at 5:00 PM America/Denver. Opens Feb 22, 2028. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
U.S. House of Representatives — At-Large
Filing window: –
Candidacy method: Party Primary · Deadline type: Party primary filing
Withdrawal deadline: Mar 20, 2028
Files with: Montana Secretary of State
Fee: $50
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration for Nomination · accessed Jul 13, 2026
Not yet independently verified
Filing for U.S. House of Representatives in Statewide for the 2028 Montana Primary Election (Jun 6, 2028) closes Mar 8, 2028 at 5:00 PM America/Denver. Opens Feb 22, 2028. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
President of the United States
Not yet published. Independent and minor party candidates must gather valid petitions instead of paying filing fee. Signature requirement changed from 5% to 4% as of 2025 legislative session.
Filing authority: Montana Secretary of State.
Next check: Sep 1, 2027.
Montana Code Annotated Title 13, Chapter 10 - Candidate Requirements · accessed Jul 13, 2026
Not yet independently verified
The official filing deadline for President of the United States in Statewide for the 2028 Montana General Election (Nov 7, 2028) has not yet been published; check with Montana Secretary of State. Source: Montana Legislature.
Statewide
Statewide Offices (General Election Write-In)
Filing window: Closes
Candidacy method: Write In · Deadline type: Write-in filing
Write-in deadline: Aug 9, 2028
Files with: Montana Secretary of State
Fee: $0
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration of Intent for Write-in Candidates · accessed Jul 13, 2026
Last verified Jul 13, 2026
Filing for Statewide Offices (General Election Write-In) in Statewide for the 2028 Montana General Election (Nov 7, 2028) closes Aug 9, 2028 at 5:00 PM America/Denver. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
State Legislative
Montana State Senate — Odd-numbered districts (50 total)
Filing window: –
Candidacy method: Party Primary · Deadline type: Party primary filing
Withdrawal deadline: Mar 20, 2028
Files with: Montana Secretary of State
Fee: $50
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration for Nomination · accessed Jul 13, 2026
Not yet independently verified
Filing for Montana State Senate in Statewide for the 2028 Montana Primary Election (Jun 6, 2028) closes Mar 8, 2028 at 5:00 PM America/Denver. Opens Feb 22, 2028. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
Montana House of Representatives — All 100 districts
Filing window: –
Candidacy method: Party Primary · Deadline type: Party primary filing
Withdrawal deadline: Mar 20, 2028
Files with: Montana Secretary of State
Fee: $30
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration for Nomination · accessed Jul 13, 2026
Not yet independently verified
Filing for Montana House of Representatives in Statewide for the 2028 Montana Primary Election (Jun 6, 2028) closes Mar 8, 2028 at 5:00 PM America/Denver. Opens Feb 22, 2028. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
Judicial
Montana District Court Judges — Various districts
Filing window: –
Candidacy method: Nonpartisan · Deadline type: Nonpartisan filing
Write-in deadline: Mar 8, 2028 · Withdrawal deadline: Mar 20, 2028
Files with: Montana Secretary of State
Fee: $0 (judicial candidates)
Montana Code Annotated Title 13, Chapter 10, Part 2 - Declaration for Nomination · accessed Jul 13, 2026
Not yet independently verified
Filing for Montana District Court Judges in Statewide for the 2028 Montana Primary Election (Jun 6, 2028) closes Mar 8, 2028 at 5:00 PM America/Denver. Opens Feb 22, 2028. This date is calculated from statute and is not an official calendar date. Source: Montana Legislature.
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Electbase compiles these dates from official state sources as a workflow aid. It is not legal advice. Confirm every deadline with your filing authority before you rely on it.
Last updated August 27, 2026