   RAUNI MACHADO v. WILBERT TAYLOR ET AL.
                (SC 19838)
Rogers, C. J., and Palmer, McDonald, Espinosa, Robinson and Vertefeuille, Js.

                                  Syllabus

Pursuant to statute (§ 52-556), any person injured through the negligence
   of any state official or employee in the course of operating a motor
   vehicle owned and insured by the state against personal injuries or
   property damage shall have a right of action against the state to recover
   damages for such injury.
The plaintiff brought an action pursuant to § 52-556 against the defendant
   state Department of Transportation, seeking to recover damages for
   personal injuries he sustained as a result of an accident in which his
   motor vehicle was struck by a motor vehicle owned by the state and
   operated by one of its employees. Although the plaintiff alleged in his
   complaint that the state owned the vehicle, which the defendant admit-
   ted, he did not allege that the vehicle was insured by the state against
   personal injuries or property damage. Following the close of evidence
   after a bench trial, during which the plaintiff proffered no evidence that
   the vehicle was insured by the state, the defendant filed a motion for
   judgment of dismissal, pursuant to the rules of practice (§§ 10-30 [a] [1]
   and 15-8), in which it asserted that the plaintiff’s failure to establish at
   trial that the vehicle was insured by the state placed the claim outside
   the purview of the waiver of sovereign immunity in § 52-556 and deprived
   the court of subject matter jurisdiction. The plaintiff opposed that
   motion, contending that it was never in dispute that the vehicle was
   insured by the state. He attached to his motion an exhibit in which the
   defendant admitted in an interrogatory that the state maintained self-
   insurance on the vehicle. The plaintiff concurrently filed a motion to
   open the evidence to allow him to place the interrogatory into evidence.
   The defendant opposed the motion to open, arguing that the trial court
   first had to address the dispositive jurisdictional issue or, alternatively,
   that the motion should be denied because the interrogatory could have
   been proffered earlier. Prior to rendering judgment for the plaintiff, the
   trial court denied the defendant’s motion for judgment of dismissal but
   did not rule on the plaintiff’s motion to open. The court’s stated rationale
   for its denial of the defendant’s motion was the defendant’s delay in
   filing the motion or the application of the doctrine of laches. On the
   defendant’s appeal challenging the court’s decision on the motion for
   judgment of dismissal, held that the trial court improperly denied the
   defendant’s motion on the basis of delay or laches and rendered judg-
   ment for the plaintiff without first resolving whether the defendant’s
   motion raised a colorable jurisdictional issue and, if so, whether the
   court had jurisdiction over the cause of action, and, because the record
   in the case suggested that the various issues potentially implicated by
   the claims and circumstances were better left to be resolved in the first
   instance by the trial court, the judgment was reversed and the case was
   remanded to that court to resolve the jurisdictional challenge: to the
   extent that the defendant sought to challenge the trial court’s subject
   matter jurisdiction through its motion, pursuant to Practice Book § 15-
   8, for failure to make out a prima facie case, such a motion was procedur-
   ally improper, and the trial court should have considered the jurisdic-
   tional issue raised by the defendant in its motion under Practice Book
   § 10-30, the appropriate procedure for challenging subject matter juris-
   diction; moreover, the trial court was required to resolve the question of
   whether it had jurisdiction irrespective of the propriety of the procedural
   vehicle by which it was raised, and delay or laches was not a proper
   basis on which to deny a challenge to the trial court’s subject matter
   jurisdiction in relation to whether a claim falls within the statutory
   waiver of sovereign immunity.
            Argued March 28—officially released July 25, 2017

                             Procedural History
   Action to recover damages for personal injuries sus-
tained as a result of the named defendant’s negligent
operation of a motor vehicle owned by the state,
brought to the Superior Court in the judicial district of
New Haven at Meriden, where the action was dismissed
as against the named defendant; thereafter, the matter
was tried to the court, Cronan, J.; subsequently, the
court denied the defendant Department of Transporta-
tion’s motion for judgment of dismissal and rendered
judgment for the plaintiff, from which the defendant
Department of Transportation appealed. Reversed; fur-
ther proceedings.
  Ronald D. Williams, Jr., for the appellant (defendant
Department of Transportation).
  Nathan C. Nasser, with whom was Robert A. Shrage,
for the appellee (plaintiff).
                          Opinion

   McDONALD, J. The sole issue in this appeal is
whether a party’s delay in raising a challenge to the trial
court’s subject matter jurisdiction is a proper ground on
which to decline to dismiss the action. The defendant
state Department of Transportation appeals from the
trial court’s judgment in favor of the plaintiff, Rauni
Machado, in his negligence action, following the trial
court’s denial of the defendant’s motion for judgment
of dismissal premised on the plaintiff’s failure to allege
and prove an element of the statutory waiver of sover-
eign immunity cited as authority to bring the action.
We agree with the defendant that the timing of its
motion was an improper ground on which to deny the
motion for judgment of dismissal insofar as it chal-
lenged subject matter jurisdiction. Accordingly, we
reverse the judgment of the trial court and remand the
case for reconsideration of that motion.
   The record reveals the following undisputed facts
and procedural history. A motor vehicle operated by
the plaintiff was struck by a motor vehicle owned by
the state and operated by a state employee. In Novem-
ber, 2012, the plaintiff brought the present action
against the defendant, seeking to recover damages for
personal injuries sustained as a result of the accident
and alleging in his complaint that General Statutes § 52-
556 authorized the action.1 Section 52-556 provides:
‘‘Any person injured in person or property through the
negligence of any state official or employee when
operating a motor vehicle owned and insured by the
state against personal injuries or property damage shall
have a right of action against the state to recover dam-
ages for such injury.’’ The complaint alleged that the
state owned the vehicle, which the defendant admitted,
but it did not allege that the vehicle was insured by the
state against personal injuries or property damage. In
November, 2015, the matter proceeded to a bench trial,
during which the plaintiff proffered no evidence to
establish that the vehicle was insured by the state.
  After the close of evidence but before either party
had submitted posttrial briefs, the defendant filed a
motion captioned ‘‘Motion for Judgment of Dismissal,’’
pursuant to both Practice Book §§ 10-30 (a) (1)2 and
15-8,3 asserting that the plaintiff’s failure to offer evi-
dence at trial to establish that the vehicle was insured
by the state placed the claim outside the purview of
the waiver of sovereign immunity in § 52-556, and thus
deprived the court of subject matter jurisdiction. The
plaintiff filed an opposition to the motion, in which he
contended that it was never in dispute that the vehicle
was insured by the state or that his claim fell within
the waiver under § 52-556. The plaintiff attached to that
opposition as an exhibit an interrogatory dated more
than two years before trial, in which the defendant
acknowledged that the state maintained self-insurance
on the vehicle. The plaintiff concurrently filed a request
to open the evidence to allow him to place the interroga-
tory into evidence. The defendant opposed the motion
to open, arguing that the trial court first had to address
the dispositive jurisdictional issue, and, alternatively,
that the motion should be denied on the merits because
the interrogatory could have been proffered earlier.
Although the defendant argued that it would be prejudi-
cial to consider the interrogatory, it did not contend
that it would have introduced evidence to rebut its
response in the interrogatory. See Piantedosi v. Flor-
idia, 186 Conn. 275, 278, 440 A.2d 977 (1982) (‘‘An
answer filed by a party to an interrogatory has the same
effect as a judicial admission made in a pleading or in
open court. It relieves the opposing party of the neces-
sity of proving the facts admitted . . . but it is not
conclusive upon him and will not prevail over evidence
offered at the trial.’’ [Internal quotation marks omit-
ted.]); see also General Statutes § 52-200 (same).
   The trial court ruled on the defendant’s motion for
a judgment of dismissal in its memorandum of decision
rendering judgment for the plaintiff, but it did not rule
on the plaintiff’s motion to open evidence. In consider-
ing the defendant’s motion attacking the plaintiff’s fail-
ure of proof under two rules of practice, the trial court
did not expressly consider whether the motion raised
a jurisdictional issue or a challenge to the legal suffi-
ciency of the claim. See Egri v. Foisie, 83 Conn. App.
243, 246–51, 848 A.2d 1266 (failure to allege negligent
operation of vehicle as required by § 52-556 should have
been raised through motion to strike, not motion to
dismiss, because plaintiff potentially could state claim
under statute), cert. denied, 271 Conn. 931, 859 A.2d
930 (2004); see also In re Jose B., 303 Conn. 569, 572–80,
34 A.3d 975 (2012) (clarifying that absence of jurisdic-
tion means that plaintiff could not establish jurisdic-
tional facts, not that plaintiff had not done so). Nor did
the court consider whether the factual issue asserted
in the defendant’s motion, alone or in combination with
the interrogatory, raised an issue of fact that required
further proceedings to resolve the jurisdictional issue.
See Standard Tallow Corp. v. Jowdy, 190 Conn. 48, 56,
459 A.2d 503 (1983) (trial court may hold hearing if
issues of fact are necessary to determine jurisdiction);
see also Conboy v. State, 292 Conn. 642, 651–54, 974
A.2d 669 (2009) (describing procedures for addressing
jurisdictional challenge depending on point at which
issue raised). Instead, the trial court stated that it was
denying the motion, cited the procedural history of the
case, and provided the following comments: ‘‘The court
finds it somewhat odd that the defendant [waited] until
the close of evidence to file a motion that potentially
could be dispositive of a case that is over three years
old. In addition, a strong argument can be made that
the [d]octrine of [l]aches may well apply here.’’
  The defendant appealed from the judgment in the
plaintiff’s favor, solely challenging the court’s decision
on its motion, and we transferred the appeal to this
court. See General Statutes § 51-199 (c); Practice Book
§ 65-1. The defendant claims that the trial court improp-
erly denied its motion on the basis of delay and laches
because neither ground is a proper basis on which to
deny a motion raising a lack of subject matter jurisdic-
tion, and, even if such grounds were proper, the delay
was justified. The plaintiff contends that the court prop-
erly denied the motion, albeit for reasons not stated by
the court. We agree with the defendant that we must
assume that the trial court denied the motion on the
sole basis that the trial court articulated. We further
agree that the stated rationale was not a proper basis
on which to deny the defendant’s motion purportedly
raising a challenge to the court’s jurisdiction.
   We observe at the outset that, although the defen-
dant’s motion for judgment of dismissal was made pur-
suant to Practice Book §§ 10-30 (a) (1) and 15-8, our
analysis focuses on the former. To the extent the defen-
dant sought to challenge the court’s subject matter juris-
diction through a motion for judgment of dismissal for
failure to make out a prima facie case under the latter
provision, the motion was procedurally improper for
two reasons. First, a motion to dismiss pursuant to
Practice Book § 10-30 (a) (1) is the appropriate proce-
dure for challenging subject matter jurisdiction. See St.
George v. Gordon, 264 Conn. 538, 545, 825 A.2d 90
(2003). Second, to the extent the motion sought a judg-
ment of dismissal pursuant to Practice Book § 15-8, the
defendant waived a claim that the plaintiff failed to
make out a prima facie case under § 52-556 by pre-
senting evidence in its defense and waiting until the
close of evidence to file the motion. See, e.g., Cormier
v. Fugere, 185 Conn. 1, 2, 440 A.2d 820 (1981) (‘‘[a]
motion for judgment of dismissal must be made by the
defendant and decided by the court after the plaintiff
has rested his case, but before the defendant pro-
duces evidence’’).
    Although the motion was captioned in accordance
with Practice Book § 15-8 as a motion for judgment of
dismissal, the trial court nonetheless was required to
consider the jurisdictional issue raised under Practice
Book § 10-30. See Franco v. East Shore Development,
Inc., 271 Conn. 623, 629 n.7, 858 A.2d 703 (2004)
(‘‘[w]here a party captions its motion improperly, we
look to the substance of the claim rather than the form’’
[internal quotation marks omitted]). ‘‘[O]nce the ques-
tion of lack of jurisdiction of a court is raised, [it] must
be disposed of no matter in what form it is presented
. . . and the court must fully resolve it before proceed-
ing further with the case.’’ (Internal quotation marks
omitted.) Golden Hill Paugussett Tribe of Indians v.
Southbury, 231 Conn. 563, 570, 651 A.2d 1246 (1995);
see also Baldwin Piano & Organ Co. v. Blake, 186
Conn. 295, 297, 441 A.2d 183 (1982) (‘‘[w]henever the
absence of jurisdiction is brought to the notice of the
court or tribunal, cognizance of it must be taken and
the matter passed upon before it can move one further
step in the cause; as any movement is necessarily the
exercise of jurisdiction’’ [internal quotation marks omit-
ted]). The trial court, therefore, was required to resolve
the question of whether it had jurisdiction over the
subject matter irrespective of the propriety of the proce-
dural vehicle by which it was raised.
   Accordingly, the question before us is whether delay
or the doctrine of laches is a proper basis on which to
deny the defendant’s challenge to the trial court’s sub-
ject matter jurisdiction in relation to whether the plain-
tiff’s claim falls within the statutory waiver of sovereign
immunity. We conclude that they are not.
   It is well established that ‘‘[t]he doctrine of sovereign
immunity implicates subject matter jurisdiction and is
therefore a basis for granting a motion to dismiss. . . .
A determination regarding a trial court’s subject matter
jurisdiction is a question of law. When . . . the trial
court draws conclusions of law, our review is plenary
and we must decide whether its conclusions are legally
and logically correct and find support in the facts that
appear in the record.’’ (Citation omitted; internal quota-
tion marks omitted.) Miller v. Egan, 265 Conn. 301, 313,
828 A.2d 549 (2003).
   Delay suggests a failure to comply with a time limita-
tion, whether specific or governed by a reasonableness
standard. See General Statutes § 52-128 (after amend-
ment, ‘‘the defendant shall have a reasonable time to
answer the same’’); Practice Book § 10-59 (plaintiff may
amend pleading as of right during first thirty days after
return day). ‘‘Laches consists of an inexcusable delay
which prejudices the defendant. . . . We have said on
other occasions that [t]he defense of laches does not
apply unless there is an unreasonable, inexcusable, and
prejudicial delay in bringing suit. . . . Delay alone is
not sufficient to bar a right; the delay . . . must be
unduly prejudicial.’’4 (Internal quotation marks omit-
ted.) Doe v. Hartford Roman Catholic Diocesan Corp.,
317 Conn. 357, 398–99, 119 A.3d 462 (2015). We have
never stated that delay or laches precludes a jurisdic-
tional challenge.
   Indeed, such a conclusion would contravene well
settled law. ‘‘[A] court lacks discretion to consider the
merits of a case over which it is without jurisdiction.
. . . The objection of want of jurisdiction may be made
at any time . . . [a]nd the court or tribunal may act
on its own motion, and should do so when the lack of
jurisdiction is called to its attention. . . . The require-
ment of subject matter jurisdiction cannot be waived
by any party and can be raised at any stage in the
proceedings.’’ (Emphasis added; internal quotation
marks omitted.) Fairfield Merrittview Ltd. Partner-
ship v. Norwalk, 320 Conn. 535, 548, 133 A.3d 140 (2016);
accord Practice Book § 10-33; St. Paul Travelers Cos.
v. Kuehl, 299 Conn. 800, 815–16, 12 A.3d 852 (2011).
Hence, this court has recognized that it is proper to
consider a challenge to subject matter jurisdiction
raised posttrial before the trial court; see Fairfield Mer-
rittview Ltd. Partnership v. Norwalk, supra, 552; Chap-
man Lumber, Inc. v. Tager, 288 Conn. 69, 86 n.22, 952
A.2d 1 (2008); raised for the first time on appeal; see
Perez-Dickson v. Bridgeport, 304 Conn. 483, 506, 43
A.3d 69 (2012); and even raised in a collateral attack
under certain circumstances. See Investment Associ-
ates v. Summit Associates, Inc., 309 Conn. 840, 855, 74
A.3d 1192 (2013). Only in the context of a collateral
attack on the judgment by way of a separate action
have we considered whether the parties had a full
opportunity originally to contest the jurisdiction of the
adjudicatory tribunal. See id.
   Accordingly, it was improper for the trial court to
deny the defendant’s motion and render judgment in
favor of the plaintiff without first resolving whether
the defendant’s motion raised a colorable jurisdictional
issue, and, if so, whether it had jurisdiction over the
cause of action. Although this court will resolve a juris-
dictional challenge raised for the first time on appeal,
the record in this case suggests that the various issues
potentially implicated by the claims and circumstances
are better left to be resolved in the first instance by the
trial court. To the extent that further proceedings are
necessary to resolve those issues, nothing stated in
this opinion precludes such proceedings in accordance
with law.
  The judgment is reversed and the case is remanded
for further proceedings.
      In this opinion the other justices concurred.
  1
     The plaintiff also named the state employee, Wilbert Taylor, as a defen-
dant. Taylor successfully moved to dismiss the action against him on the
basis of immunity under General Statutes § 4-165. All references to the
defendant herein are to the Department of Transportation.
   2
     Practice Book § 10-30 (a) (1) provides in relevant part: ‘‘A motion to
dismiss shall be used to assert . . . lack of jurisdiction over the subject
matter . . . .’’
   3
     Practice Book § 15-8 provides in relevant part: ‘‘If, on the trial of any
issue of fact in a civil matter tried to the court, the plaintiff has produced
evidence and rested, a defendant may move for judgment of dismissal, and
the judicial authority may grant such motion if the plaintiff has failed to
make out a prima facie case. . . .’’
   4
     We have not previously considered whether laches may be asserted by
a plaintiff in an offensive manner, a matter on which other courts disagree,
or whether it can be asserted to bar a motion as opposed to a cause of
action, and our decision should not be construed to recognize the propriety
of such an action. We need not resolve these issues, however, for purposes
of this appeal.
