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

TL;DR

My distribution has a median of 28 provisionally closed chapters and a mean of 27.5. The official count is 18 after the 14 July 2026 accession conference, so the forecast adds 9 to 10 closures over the final five and a half months of 2026 (Council of the EU, 14 July 2026). I put 33% on 30 or more chapters and 11% on all 33 chapters being closed by 31 December 2026.

Context

Montenegro is the most advanced current EU candidate in the formal chapter process. The latest official EU count is 33 chapters opened and 18 provisionally closed after the 28th EU-Montenegro Accession Conference closed Chapter 8, competition policy, and Chapter 29, customs union, on 14 July 2026 (Council Montenegro page; Council press release). The remaining chapters are 1, 9, 12, 14, 15, 16, 17, 18, 19, 22, 23, 24, 27, 31, and 33, derived from the closed-chapter list and the Council's 18-of-33 count (Council Montenegro page).

The process is not automatic once Montenegro is technically ready. Accession negotiations are intergovernmental, the General Affairs Council supervises them, and enlargement decisions generally require unanimous agreement among all EU member states (Council enlargement explainer). The remaining political windows are narrow but real: the Council calendar lists General Affairs Council meetings on 3-4 September, 22 September, 13 October, 19 November, 23 November, and 15 December 2026 (Council meeting calendar).

Evidence

The historical data are lumpy. The unit is provisionally closed chapters at accession conferences; the coverage window is 18 December 2012 through 14 July 2026; the sample has 10 closure events; the source vintage is official EU and government material available on 19 July 2026. The full closure history is:

A straight-line model from 2026 alone is too low. Montenegro closed 6 chapters in 194 days from 1 January to 14 July 2026, which linearly implies about 5 more by year-end and a final count near 23. But chapter closures arrive in packages, and the best analogue, Croatia, closed 11 chapters in 2010 and reached 28 of 35 temporarily closed chapters by December 2010 before the EU closed negotiations on 30 June 2011 (Croatian MFA, 22 Dec 2010; Croatian MFA negotiation process). The analogue shows that fast endgames happen, but it also argues against treating 33 as the base case.

The strongest positive evidence is that the EU is already doing endgame work. On 30 June 2026 the Commission adopted a Montenegro financial package under Chapter 33 and said this followed member-state agreement to start drafting the accession treaty; it also said it would submit a draft common position on Chapter 33 (European Commission, 30 Jun 2026). The Council's ad hoc working party for drafting Montenegro's accession treaty was also on the official Council calendar in May 2026 (Council, 20 May 2026). This is stronger than normal candidate-country rhetoric.

Montenegro's own implementation plan is also specific. Its 2026-2027 accession programme covers 581 acts across all 33 chapters, with 495 acts planned for 2026: 67 strategic documents, 119 laws, and 309 by-laws; obligations tied to chapter closure were planned for the first two quarters of 2026 (EU4ME, 31 Jan 2026). The largest 2026 loads were Chapter 12 with 80 obligations, Chapter 14 with 75, Chapter 1 with 71, Chapter 27 with 37, and Chapter 23 with 28, which shows both ambition and why the remaining set is hard (EU4ME, 31 Jan 2026).

The freshest chapter-level signals are positive. On 16 July 2026, Minister Maida Gorčević told RTCG that Chapters 14 and 31 were ready or technically ready, that several chapters were already before the Commission, and that internal readiness had to be finished by the end of August, with no normal summer break for the government or parliament (RTCG, 16 Jul 2026). RTCG also reported that Montenegro had fully met the final benchmark requirements for Chapter 19, social policy and employment, while the EU delegation said social dialogue would continue to be monitored after closure (RTCG, 16 Jul 2026). The same day, Parliament elected two remaining Constitutional Court judges, restoring full composition after years of crisis, and Commissioner Marta Kos linked that institution directly to Chapter 23 and to closing the accession negotiations (RTCG, 16 Jul 2026; RTCG, 16 Jul 2026).

The negative evidence is that the remaining tail is not a random sample. Chapters 23 and 24 are the rule-of-law core, Chapter 27 on environment and climate change remains administratively heavy, Chapter 33 is budgetary endgame work, and Chapter 31 is exposed to bilateral politics. The 2026 Rule of Law Report says the government adopted constitutional-amendment proposals addressing Commission and Venice Commission recommendations, but final adoption still requires a two-thirds parliamentary majority; it also records continuing human-resource and digitalisation limits in the judiciary (European Commission Rule of Law Report: Montenegro, 17 Jul 2026). The 2025 Montenegro report said Chapter 27 work had to intensify, and that only 109 of 281 planned action-plan activities had been implemented in the relevant report, or 38% (European Commission Montenegro Report 2025).

The clearest veto risk is Croatia. Vijesti reported on 10 July 2026 that Chapter 14 was ready and that every EU member except Croatia had given a green light, but Croatia held it over cabotage concerns; the same report said Croatia had already blocked Chapter 31 over bilateral disputes (Vijesti, 10 Jul 2026). On 5 June 2026, Croatian Prime Minister Andrej Plenković said further progress on Chapters 31, 23, and 24 depended on preconditions tied to open Croatia-Montenegro issues, including Morinj compensation, 14 missing persons, war-crimes prosecution, property rights, the training ship Jadran, the Kotor pool name, and border talks (Vijesti, 5 Jun 2026). That makes a final count in the high 20s or low 30s more probable than a clean 33.

I used a scenario-weighted count model rather than independent per-chapter probabilities, because closures are correlated by Council windows, Commission packaging, and member-state vetoes. I put 0.05% on a count below 18 through a reopening or count-loss edge case, 11% on 22 or fewer chapters, 56% on 23-29, 23% on 30-32, and 11% on all 33. The resulting mean is 27.5, the median is 28, the 10th percentile is 22, and the 90th percentile is 33.

What's non-obvious

The obvious base-rate read says 15 more chapters in less than six months is too many. That misses the stage of the file. Montenegro is not trying to open new chapters; it has opened all 33, passed the 2024 interim-benchmark gate for Chapters 23 and 24, and now has EU treaty-drafting and Chapter 33 financial work under way (Council, 26 Jun 2024; European Commission, 30 Jun 2026). That is why my forecast sits well above a linear extrapolation from the first half of 2026.

The other hidden crux cuts the other way. Chapter 14 appears to have been technically ready before the July accession conference, but did not close because Croatia withheld consent; Chapter 31 has the same veto problem in a more political form (Vijesti, 10 Jul 2026). Commissioner Kos also said Montenegro could still become a member in 2028 even if it did not close all chapters by the end of 2026, which lowers the pressure to force every hard file through before 31 December (Vijesti, 14 Jul 2026).

Limitations

The main gap is real-time chapter readiness. The Commission and Council do not publish a live chapter-by-chapter closure probability table, and the decisive common positions often become visible only near an accession conference. Some of the best current signals on Chapters 14, 19, and 31 come from Montenegrin media or government statements, not from final EU common positions.

The second gap is member-state politics. Croatia's objections are visible, but informal concerns from other member states could emerge late in COREPER or Council working-party discussions. The 2026 enlargement package is also not yet published, so the freshest official assessment is the July 2026 Rule of Law Report, not a full autumn enlargement report with a chapter-by-chapter readiness judgment (European Commission Rule of Law Report: Montenegro, 17 Jul 2026).