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

TL;DR

I forecast 28 chapters provisionally closed at the end of 2026, with a mean of 27.2, a median and mode of 28, and a central 50% range of 26–29. Montenegro starts from 18 closed chapters after the 14 July conference and should finish most ordinary technical files, but Croatia's active demands on the accession endgame block the clean-sweep path. My distribution gives 17% to 30 or more chapters, 3% to all 33, and a negligible 0.03% to falling below the current count through reopening.

Context

The verified baseline is 18 of 33 chapters provisionally closed as of 14 July 2026. The 15 still open are Chapters 1, 9, 12, 14, 15, 16, 17, 18, 19, 22, 23, 24, 27, 31 and 33; all 33 have been opened, and the Council's official page was last reviewed on 28 July 2026.

Formal closure is not the same as Montenegro passing a law or the Commission judging a file technically ready. A chapter counts only after the Commission and Council process produces a common EU position, all member states consent, and an Accession Conference formally calls it provisionally closed; the Council decides on accession steps by unanimity.

Evidence

The historical record is lumpy. Montenegro closed only three chapters in the first twelve years of talks, then 15 chapters across seven formal closure conferences from December 2024 through July 2026. The table is the full closure history through the forecast cutoff; the unit is chapters formally provisionally closed at each conference.

The best completed reference class is Croatia. It closed 11 of its 35 chapters during calendar 2010, ended that year with 28 closed, and finished the remaining seven by 30 June 2011; the year-end stock and 2010 flow are recorded by Croatia's foreign ministry. This shows that endgames accelerate. It also shows how demanding Montenegro's headline target is: Montenegro must close 15 chapters in less than five months, versus Croatia's seven in the first half of its final year.

The positive evidence is real. Ireland made advancing Montenegro a presidency goal before taking the Council chair on 1 July 2026. The Council created a working party to draft Montenegro's accession treaty on 22 April 2026, and the Commission presented the Chapter 33 financial package on 30 June 2026. Montenegro's European affairs minister said a further conference was planned for September 2026. The government also reported about 100 EU-linked laws adopted during 2026 through 23 July, while late-July steps included visa-policy alignment for Chapter 24 and the filling of Constitutional Court vacancies. These are government claims or domestic actions, not closure decisions, so I use them as leading indicators rather than completed milestones.

The remaining stock is harder than the chapters already cleared. The Commission's latest full chapter-by-chapter assessment was published on 4 November 2025 and covers developments from 1 September 2024 through 1 September 2025. Its vintage is stale relative to the 2026 reform sprint, but it still identifies the structural load: Chapters 27 and 33 were only at some level of preparation, several other open chapters were moderately prepared, and Chapters 23 and 24 still needed implementation, appointments, capacity and stronger enforcement track records.

Croatia is the clearest downside. It blocked Chapter 31 in the final stage and then withheld approval for technically ready Chapter 14 in July over cabotage and related concerns, according to Vijesti's reporting. On 22 July 2026, Croatia publicly demanded action on compensation for former detainees, 14 missing persons, war-crimes cases, property claims, the Morinj memorial, the Kotor pool name, the maritime boundary and the training ship Jadran. I read the escalation from one blocked chapter to two as evidence that this is leverage backed by a willingness to delay, not a routine procedural hold. Commissioner Marta Kos also said that a small spillover into January would not prevent 2028 membership, which reduces the cost of missing the exact year-end deadline (RTNK, 15 July 2026).

My model starts at 18 and separates the 15 open chapters into 11 mainly technical files, the Croatia-affected Chapters 14 and 31, and the fundamentals Chapters 23 and 24. The core scenario weights are 35% for a strong endgame, 48% for central progress, 15% for a slow endgame and 2% for disruption. I then add a 4% focal path ending at 30—ordinary technical files plus Chapter 14 close, while 31, 23 and 24 remain—and a 2% comprehensive-bargain path to 33. A 0.03% reopening tail respects the resolution rules. This produces a mean of 27.2, a median and mode of 28, an 80% range of 24–30, 17% probability of at least 30, and 3% probability of 33.

What's non-obvious

The endgame is not 15 independent coin flips. Under the revised methodology, the fundamentals govern the pace and are intended to close last, while Croatia can keep Chapter 31 open even if Montenegro completes the domestic work (Council methodology). That makes 30 more likely than 31 or 32: Montenegro can clear nearly every ordinary chapter yet stop with Chapters 31, 23 and 24 still open. A full political package can jump from that plateau to 33, which is why the distribution has a small second peak at completion.

The public narrative also overweights laws passed in Podgorica. The bottleneck has shifted from drafting legislation to Commission verification, Council processing and unanimity. The official Croatian statement arrived after the July conference and became more explicit, while EU officials simultaneously normalized a short slip into 2027. Those two signals outweigh the government's claim that every remaining file is almost finished.

Uncertainties

The largest gap is the absence of a fresh public Commission readiness matrix for all 15 open chapters. The November 2025 report is the latest comprehensive assessment, while most 2026 evidence comes from Montenegro's own ministries and Parliament. I also could not verify any private EU-mediated bargain with Croatia; no public evidence of flexibility does not prove that backchannel talks are absent.

The announced September conference was a Montenegrin minister's statement, not yet a formal Council notice at the cutoff. The forecast would move upward if the Commission sends a large set of draft closing positions to the Council by early autumn, if Croatia accepts a roadmap rather than final settlement, or if Chapters 23 and 24 receive a positive implementation assessment. It would move downward if September produces only Chapter 14 or no closures, or if Croatia extends its objections beyond Chapters 14 and 31.