How many of the negotiating chapters required to join the EU will Montenegro have closed at the end of 2026?

TL;DR

I forecast Montenegro ends 2026 with 26 provisionally closed chapters, with a 12% chance of closing all 33 by the deadline.

Context

As of 7 June 2026, the best official count is 14 provisionally closed chapters out of 33: the Council says all 33 chapters have been opened and 14 provisionally closed after the 17 March 2026 Accession Conference, and the Commission repeated the 14-chapter count on 20 May 2026 (Council Montenegro profile, Commission news, 20 May 2026). The forecast window is just under seven months, and the outcome only moves when an EU-Montenegro Accession Conference formally says a chapter is provisionally closed.

The political goal is real. The Commission said on 4 November 2025 that Montenegro was on track to close accession negotiations by end-2026 if it maintained reform pace, and European Council President António Costa said on 5 June 2026 that the EU had started drafting Montenegro’s accession treaty in May 2026, aimed at Montenegro becoming the EU’s 28th member state by 2028 (Commission Enlargement Package, 4 November 2025, Costa remarks, 5 June 2026). That does not make 33 the base case. The remaining chapters include the hardest rule-of-law, environmental, budgetary, and bilateral files.

Evidence

The historical series is short and lumpy. Units are provisionally closed negotiating chapters. Coverage is December 2012 through March 2026. The sample is eight formal closure events, using current official EU and Montenegrin-source vintage available on 7 June 2026.

This history has two regimes. Montenegro closed only 3 chapters in roughly 12 years, then closed 11 more after the June 2024 rule-of-law milestone for Chapters 23 and 24 opened a new phase in negotiations (Commission Montenegro Report 2025). So the old 2012-2023 pace is too low, but the last 15 months are also too optimistic because many easy chapters have already been removed from the pool.

The strongest near-term evidence is the Council paperwork. The 9 April 2026 Council Working Party page lists draft EU common positions for Chapter 2, freedom of movement for workers, and Chapter 28, consumer and health protection; the 2 June and 9 June 2026 Working Party pages list draft common positions for Chapter 8, competition policy, and Chapter 29, customs union (Council Working Party, 9 April 2026, Council Working Party, 2 June 2026, Council Working Party, 9 June 2026). I treat those four chapters as more likely than not to close by year-end, and likely to bring the count to about 18. I do not treat them as already closed. Local reporting on 19 May 2026 said the expected May intergovernmental conference had slipped, with only Chapters 2 and 28 looking clearly ready, Chapter 29 submitted, and Chapter 9 delayed (Vijesti, 19 May 2026).

The next signal is institutional. Council pages show an ad hoc working party on drafting Montenegro’s accession treaty meeting on 2 June 2026, after earlier May meetings, with more June and July meetings scheduled; Costa’s 5 June statement confirms that this is not only a technical rumor (Council accession-treaty working party, 2 June 2026, Costa remarks, 5 June 2026). This pushes the upper tail up: if EU governments decide to meet the 2026 target, remaining chapters can close in large packages rather than one by one.

The drag is the remaining workload. Montenegro’s 2026-2027 accession programme covers 581 acts, with 495 planned for 2026, including 67 strategic documents, 119 laws, and 309 by-laws; the largest 2026 chapter workloads are Chapter 12 with 80 obligations, Chapter 14 with 75, Chapter 1 with 71, Chapter 27 with 37, and Chapter 23 with 28 (Ministry of European Affairs, 31 January 2026). The Commission’s 2025 report, covering 1 September 2024 to 1 September 2025, says Chapter 23 is between moderate and good preparation but still needs high-level judicial appointments and stronger final results, Chapter 24 requires full visa-policy alignment as a closing benchmark, Chapter 27 has only some level of preparation, and Chapter 8 still needs a credible competition-enforcement track record (Commission Montenegro Report 2025). A May 2026 cabinet release also says the Chapter 15 energy roadmap includes steps such as a National Building Renovation Plan by the end of 2027, which shows some implementation work runs beyond the forecast window even if a political closure remains possible (Government of Montenegro, 7 May 2026).

There is a specific bilateral veto risk. Croatia has blocked Chapter 31, foreign, security and defence policy, and Croatian Prime Minister Andrej Plenković said in Tivat on 5 June 2026 that Croatia’s support for further progress on Chapters 31, 23, and 24 depends on open bilateral issues, including Morinj compensation, missing persons, war-crimes prosecution, property claims, the training ship Jadran, and border talks (Vijesti, 5 June 2026). That matters because formal chapter closure needs EU-side agreement, not only Montenegrin legislation.

My model starts from the confirmed 14. I assign 5% to 18 or fewer chapters, 28% to 19-23, 37% to 24-28, 17% to 29-32, and 12% to all 33. The mean is 25.8, the median is 26, the 10th percentile is 20, and the 90th percentile is 33. The distribution is wide because the final stage is correlated: either the rule-of-law and bilateral files unlock a year-end sweep, or several otherwise-ready chapters wait for 2027.

What's non-obvious

The positive signal is not the slogan “28 by 2028.” It is the administrative machinery behind it: draft common positions for four named chapters and a Council working party already drafting the accession treaty (Council Working Party, 2 June 2026, Council accession-treaty working party, 2 June 2026). That is why I put little mass on outcomes near the current 14.

The negative signal is selection bias. The chapters left are not a random sample. They include rule of law, environment, competition policy, financial and budgetary provisions, and a Croatia-sensitive foreign-policy chapter. Also, Montenegro can still be a plausible 2028 entrant if some final chapters close in early 2027 rather than by 23:59 CET on 31 December 2026. That timing distinction is the main reason I keep the all-33 probability at 12% rather than making it the base case.

Limitations

The decisive documents are partly opaque. Public Council pages show that draft common positions exist, but not their full content or member-state reserves (Council Working Party, 9 June 2026). The latest full Commission country report was published on 4 November 2025 and covers evidence only through 1 September 2025, so it is stale for the 2026 legislative sprint (Commission Montenegro Report 2025). I found no official EU announcement, as of 7 June 2026, of a post-March 2026 Montenegro accession conference; the 16 June General Affairs Council page had preparatory documents but not a Montenegro accession-conference item yet (General Affairs Council, 16 June 2026).