Peremptory challenges to a judge under CCP 170.6: which clock you are on

Who gets a challenge, and how many

One per party and one per side, and the side is the unit that runs out.

CCP 170.6(a)(1) reaches "[a] judge, court commissioner, or referee of a superior court" and bars that officer from trying the action or hearing "any matter therein that involves a contested issue of law or fact" once prejudice is established under the section. CCP 170.6(a)(2) lets "[a] party to, or an attorney appearing in, an action or proceeding" establish it, and the prejudice alleged can run against the party, the attorney, or the interest of either.

That is CCP 170.6(a)(4). A challenge by any party on a side uses that side's challenge for everyone on it. Whether two coparties share a side turns on their interests. In Home Ins. Co. v. Superior Court (2005) 34 Cal.4th 1025 the Supreme Court held that the party seeking a second challenge carries the burden of showing its interests are substantially adverse to those of the coparty that already challenged, that adversity is not presumed, and that whether two parties sit on the same side is a question of fact. It held that primary and excess carriers do not necessarily have substantially adverse interests, and upheld an order striking an excess carrier's challenge after a primary carrier on the same side had used one.

A party brought in late is measured the same way. If nobody on its side has used the challenge, a late-appearing party gets its own window running from its appearance. If someone on its side already has, the late arrival "has no right to challenge the then-current judge because that side has used its one challenge." School Dist. of Okaloosa County v. Superior Court (1997) 58 Cal.App.4th 1126, 1134-1135. "Appearance" in section 170.6 means a general appearance. Id. at 1131; see id. at 1132, fn. 3.

The limit binds the party as well as the lawyer, and that is the half that catches new counsel. Substituting in does not give the client back a challenge it already spent. What else you inherit is in substituting into a case before trial.

Four clocks, and how to tell which one you are on

Work out how the judge was assigned before you count anything. The assignment picks the rule.

The Supreme Court's starting point: "As a general rule, a challenge of a judge is permitted under section 170.6 any time before the commencement of a trial or hearing." People v. Superior Court (Lavi) (1993) 4 Cal.4th 1164, 1171. Subdivision (a)(2) then carves out three exceptions, and the general rule governs only when none of them applies.

All purpose assignment. "If directed to the trial of a civil cause that has been assigned to a judge for all purposes, the motion shall be made to the assigned judge or to the presiding judge by a party within 15 days after notice of the all purpose assignment, or if the party has not yet appeared in the action, then within 15 days after the appearance." CCP 170.6(a)(2). Fifteen calendar days, computed under CCP 12 by excluding the first day and including the last, with a last day that falls on a holiday carried to the next day that is not one under CCP 12a(a). The label on the order is prima facie evidence of what kind of assignment it was, and it does not automatically control. Lavi, 4 Cal.4th at 1179. The assignment qualifies when it "instantly pinpoint[s]" the judge who will preside at trial and that judge is expected to process the case "in its totality" from the assignment forward. Id. at 1180.

Master calendar. "If directed to the trial of a cause with a master calendar, the motion shall be made to the judge supervising the master calendar not later than the time the cause is assigned for trial." CCP 170.6(a)(2). A department's master calendar label is persuasive and not conclusive. Lavi, 4 Cal.4th at 1174. "For the master calendar rule to apply, there must be a true master calendar assignment of a ready case to a ready courtroom." Id. at 1177. A master calendar department that sends a case out for trial setting on a future date has not made that kind of assignment. Id. at 1176-1177.

A known judge. "If the judge, other than a judge assigned to the case for all purposes, court commissioner, or referee assigned to, or who is scheduled to try, the cause or hear the matter is known at least 10 days before the date set for trial or hearing, the motion shall be made at least 5 days before that date." CCP 170.6(a)(2). Known does not mean certain. It means "reasonable assurance that the judge will in fact hear the case," and a party who could have learned by "further investigation or inquiry" who sits in the assigned department is treated as knowing. Lavi, 4 Cal.4th at 1183. The rule does not reach an all purpose judge, by its own words and by Lavi, 4 Cal.4th at 1182. Five days here is five calendar days counted back from the date set. If the fifth day lands on a weekend or a holiday, file earlier.

Everything else. "If the motion is directed to a hearing, other than the trial of a cause, the motion shall be made not later than the commencement of the hearing." CCP 170.6(a)(2). For a trial where nobody can say with reasonable certainty who will try it, the general rule applies and the challenge may be made any time before trial. Lavi, 4 Cal.4th at 1185. For proceedings the subdivision does not address, "the procedure specified herein shall be followed as nearly as possible."

That sentence in CCP 170.6(a)(2) is the outer limit on every clock above. The earlier limits still apply inside it.

The merits bar, and the rulings that trigger it

Pretrial rulings leave the challenge intact unless one of them decided a contested fact issue relating to the merits.

That is the last sentence of the first paragraph of CCP 170.6(a)(2), and the converse is what bites. "[A] disqualification motion cannot be filed after the challenged judge has made a determination 'of contested fact issues relating to the merits' of the case." School Dist. of Okaloosa County v. Superior Court (1997) 58 Cal.App.4th 1126, 1131.

Okaloosa put the test this way: "However important an issue may be to the outcome of a case, it is not a bar to a disqualification motion unless it requires resolution of 'contested fact issues relating to the merits' of the case." Id. at 1133. Courts classify the motion by type, in general terms, rather than by what turned on it in the particular case. Id. at 1134, fn. 4. Okaloosa held that a motion to quash for lack of personal jurisdiction is not a merits determination, even though it may resolve contested facts about the defendant's contacts with the state. Id. at 1133-1134.

Okaloosa also collected the earlier decisions. As it described them, a motion for judgment on the pleadings, a continuance motion, a summary judgment motion and an ex parte application for a temporary restraining order had each been held not to involve a merits determination, and it counted four pretrial rulings that had been held to: a motion to suppress a confession, a preliminary injunction, a summary adjudication of a "make or break" issue, and contempt. It noted that the summary adjudication decision had since been criticized. Id. at 1133. Those are that court's characterizations of other cases. Read the case that matches your ruling before you rely on the list.

The bar matters where a window is still open late in the case: a late-appearing party, a challenge under the 10 day and 5 day rule, and a challenge made under the general rule on the eve of trial.

Whether mail or electronic service extends any of it

One clock has a published answer, one has a statutory answer, and the rest either run from something nobody serves or have no answer.

The all purpose window after mailed notice. CCP 1013(a) extends "any period of notice and any right or duty to do any act or make any response within any period or on a date certain after service of the document" by five calendar days when both the place of mailing and the address are in California, 10 when either is outside California but within the United States, 12 to an address in the Secretary of State's confidentiality program, and 20 when either is outside the United States. California Business Council for Equal Opportunity v. Superior Court (1997) 52 Cal.App.4th 1100 held that "notice" in section 170.6 means notice given by the methods in the chapter that contains section 1013, including service by mail (id. at 1105-1106), and that "[s]ince section 170.6 contains no express exception to section 1013, the 10-day period of notice is extended by 5 days when notice is given by service by mail" (id. at 1107). That was the 10 day text. The current 15 days still run "after notice of the all purpose assignment," so the same reasoning reads onto them, but no decision this page relies on has said so about the 15 day version.

The same window after electronic service. CCP 1010.6(a)(3)(B) extends "[a]ny period of notice, or any right or duty to do any act or make any response within any period or on a date certain after the service of the document" by two court days after electronic service, and CCP 1010.6(a)(3)(C) applies that "in the absence of a specific exception provided by any other statute or rule of court." Section 170.6 carries no such exception, so the reasoning of California Business Council points toward two court days. No published decision this page relies on says so, and this page does not rely on it either.

The clocks with nothing served. Both extension statutes lengthen a period running after service of a document. A 15 day window that runs from your own appearance, a deadline counted back from a trial date, and a master calendar assignment that has to be met on the spot have no served document to extend from.

The 60 days after a reversal. The statute runs them from when "the party or the party's attorney has been notified of the assignment." It says notified, not served, and it contains no extension language of its own. Treat 60 as 60.

The writ. CCP 170.3(d) says "If the notice of entry is served by mail, that time shall be extended as provided in subdivision (a) of Section 1013." It says nothing about electronic service. Whether section 1010.6's default rule adds two court days to an electronically served notice of entry is not answered by either statute's text.

The form, and the five days after

The statute writes the declaration for you. Use its words.

CCP 170.6(a)(2) allows "an oral or written motion without prior notice supported by affidavit or declaration under penalty of perjury, or an oral statement under oath." Subdivision (a)(6) supplies the affidavit, captioned with the court and cause and headed "PEREMPTORY CHALLENGE," and its operative language is this:

CCP 170.6(a)(7): "Any oral statement under oath or declaration under penalty of perjury made pursuant to this section shall include substantially the same contents as the affidavit above." A declaration should track that paragraph closely.

No facts go in it. The oath is the whole showing. "[F]or purposes of this statute good faith is sufficiently established by the act of verification itself," and making the affiant "go behind his oath and prove his good faith as a matter of fact" would depart from the statutory scheme. Solberg v. Superior Court (1977) 19 Cal.3d 182, 200-201.

Direct it to the right judge. On an all purpose assignment the motion goes "to the assigned judge or to the presiding judge," and off a master calendar it goes "to the judge supervising the master calendar." Both are CCP 170.6(a)(2).

Then serve it. "A party to a civil action making that motion under this section shall serve notice on all parties no later than five days after making the motion." CCP 170.6(a)(3). The statute does not say what follows if you do not. Serve it the day you file it.

When it is timely and in form, the judge is off the case

The court's only question is whether the motion qualifies. Once it does, reassignment follows by operation of the statute.

That is CCP 170.6(a)(4). Where there is no master calendar, the matter is assigned or transferred to another judicial officer of the same court, and if the court has no other, the Chair of the Judicial Council assigns one. The Supreme Court's summary: "if the motion is timely and in proper form, the judge must recuse himself without further proof and the case must be reassigned to another judge." Solberg, 19 Cal.3d at 187.

The motive behind it does not enter into it. In Okaloosa a late-named defendant's lawyer told the plaintiffs he would challenge the judge unless they dismissed his client, then did. The court said it could find no case holding that bad faith invalidates a challenge and held that the motion "was timely and it had to be granted without regard to the disruption it may have caused in the orderly administration of this litigation." 58 Cal.App.4th at 1129-1130, 1137.

Filing it does not buy time. "Unless required for the convenience of the court or unless good cause is shown, a continuance of the trial or hearing shall not be granted by reason of the making of a motion under this section." CCP 170.6(a)(5). Any continuance that is granted is day to day or for other limited periods, with reassignment "as promptly as possible."

One judge is out of reach entirely. When a for-cause challenge under CCP 170.3(c) is sent to another judge to decide, "[n]o challenge pursuant to this subdivision or Section 170.6 may be made against the judge selected to decide the question of disqualification." CCP 170.3(c)(5).

When it is denied: a writ petition in 10 days, and nothing else

No appeal, and a 10 day window that starts on a document you may never receive.

That is CCP 170.3(d), and it governs peremptory challenges as well as challenges for cause. "[S]ection 170.3(d) prescribes the exclusive means of appellate review of an unsuccessful peremptory challenge." People v. Hull (1991) 1 Cal.4th 266, 268. The defendant in Hull went to trial before the judge she had tried to challenge and raised the denial on appeal from the judgment. The Supreme Court held the point could not be reviewed that way. Id. at 268-269, 276. Hull was a criminal case. Section 170.3(d) draws no line between civil and criminal proceedings.

A party who is denied a challenge "can file a petition for a writ of mandate and a request for a stay with the Court of Appeal." Id. at 275. The petition itself is appellate practice, and this site stops at the trial court door. What belongs here is the consequence of not filing one: "If he does not pursue this remedy, however, subsequently entered orders and judgments of the challenged judge remain valid." Guedalia v. Superior Court (1989) 211 Cal.App.3d 1156, 1163. The failure to seek the writ within the statutory period "waives any right to relief which might have otherwise pertained." Id. at 1165.

Ten calendar days, extended under CCP 1013(a) only if the notice of entry was mailed. Nothing in section 170.3(d) says who has to serve that notice. Do not wait for one. File within 10 days of the ruling and the question of when the clock started never comes up.

After a reversal: a new challenge, and 60 days to make it

A reversal can reopen the challenge against the judge who is sent the retrial, and the appellant gets one even if its side has used its challenge.

That is the second paragraph of CCP 170.6(a)(2). Three conditions sit in it. There has to be a reversal, of a decision or of a final judgment. The judge from the prior proceeding has to be the one assigned to conduct the new trial. And the motion has to come within 60 calendar days of being notified of that assignment.

The override of the one-per-side limit is written for "the party who filed the appeal that resulted in the reversal of a final judgment" and for no one else. On the text, every other party takes the post-appeal window subject to subdivision (a)(4), and even the appellant gets the override only where a final judgment was reversed.

The statute does not define "a new trial on the matter." Whether a particular remand counts turns on what the disposition sends back. Read the disposition before you count on the challenge.

The local layer

San Diego assigns every civil case when it is filed, "either to the master calendar or to a judge for all purposes." The Notice of Case Assignment and Case Management Conference that may be generated at filing includes the name and department of the assigned judge, if there is one, and the plaintiff or cross-complainant must serve it on every defendant. Construction defect cases may go to a designated construction defect department. San Diego Superior Court Local Rules, rule 2.1.3 (eff. January 1, 2026). For a party that has appeared, that notice is the obvious candidate for "notice of the all purpose assignment." A defendant served with it before it appears runs its 15 days from its own appearance, on the statute's text.

The last paragraph of rule 2.1.3 is the one to read before trial call. A case assigned to an independent calendar judge for all purposes may be reassigned to the master calendar at trial call if the case is ready and the assigned judge will not be trying it. The supervising civil judge or a delegee runs that master calendar and notifies the parties of the trial judge, and the rule then says: "Accordingly, if any of the parties intend to challenge the judge assigned for trial pursuant to Code of Civil Procedure section 170.6, subdivision (a)(2), they must do so at the time they are notified of the assignment." That is the master calendar rule, stated locally. Go to trial call with the decision made.

For Riverside and San Bernardino, and for every other county, the rule is the statewide one on this page. This site does not guess at how a department runs.