In a personal-injury case, most of the evidence that matters is held by someone who never gets sued. The treating hospital, the plaintiff's employer, the prior auto carrier, the defendant's cell provider, the retained expert's own billing office — none of them are parties, and none of them answer to the ordinary interrogatory-and-production machinery that governs the people named in the caption. Reaching their files means going outside the case, and California gives you one primary instrument for doing it: the deposition subpoena, in its three statutory flavors.
The attorneys who get burned on third-party discovery rarely lose on the merits of what they asked for. They lose on the procedure around it — a missing consumer notice, a production date set too early, a privacy objection they could have anticipated and briefed around. The statutes are specific, the deadlines are counted in days, and the custodians on the other end have no incentive to help you fix a defective subpoena. What follows is how the compliance, objection, and enforcement pieces fit together.
The three subpoenas, and why the distinction decides everything
Code of Civil Procedure section 2020.010 recognizes three ways to compel discovery from a nonparty: a subpoena for personal appearance (oral testimony), a subpoena for business records only, and a subpoena for both appearance and records. For PI practice the records-only subpoena under section 2020.410 does most of the work, because what you usually want is a certified set of medical, employment, or billing records with an affidavit of the custodian, not a live deposition.
Get the timing right on the records-only subpoena. Under section 2020.410, the date of production cannot be sooner than 20 days after the subpoena issues or 15 days after it is served, whichever is later. Custodians read those dates. Set the production date a day early and you have handed the nonparty — or opposing counsel policing the subpoena — a clean ground to refuse without ever reaching your substantive request. The subpoena also has to designate the records with reasonable particularity; a demand for \"any and all documents relating to the plaintiff\" invites a motion to quash on overbreadth before anyone argues relevance.
The consumer-notice trap under section 1985.3
This is where most third-party subpoenas in PI cases die. When the records you want are the \"personal records\" of a consumer — and section 1985.3 defines that term broadly to cover records held by physicians, hospitals, state-licensed health practitioners, attorneys, banks, insurers, and more — you cannot simply serve the custodian and wait. You must serve the consumer with a notice to consumer and a copy of the subpoena, and you must do it before the custodian is required to produce.
The mechanics matter. The consumer notice has to be served at least 10 days before the production date, and if you serve the custodian by mail you add the usual mailing extension. You then serve the custodian with proof that the consumer was notified; absent that proof of service, a conscientious custodian will not release the file. The purpose is to give the consumer — ordinarily the opposing party or a nonparty whose private records are at issue — a window to move to quash or serve a written objection before anything leaves the file room.
Employment records carry their own parallel scheme under section 1985.6, with its own employee-notice requirement. Plaintiff attorneys subpoenaing a defendant driver's employment file, or defense counsel going after the plaintiff's wage and personnel records, have to run that notice track or face the same fate. The lesson is the same in both statutes: the notice is not a courtesy, it is a condition precedent to enforceable production.
Third-party objections and the privacy balance
Assume you served everything correctly. The most common substantive objection you will meet is privacy — the nonparty, or the consumer behind the records, asserts the state constitutional privacy right under article I, section 1, usually paired with the Confidentiality of Medical Information Act (Civil Code section 56 et seq.) when the file is medical.
For years, trial courts treated any discovery touching private information as something the propounding party had to justify by a \"compelling interest\" at the threshold. The California Supreme Court closed that off in Williams v. Superior Court (2017) 3 Cal.5th 531, holding that the party asserting a privacy interest first has to show a legally protected interest, a reasonable expectation of privacy, and a serious intrusion — the framework from Hill v. National Collegiate Athletic Assn. (1994) 7 Cal.4th 1. Only when the objecting party clears that bar does the court balance the privacy interest against the need for the information, and a compelling-interest showing is required only for the most sensitive categories. Practically, Williams moved the burden off your back at the outset and onto the objector to establish a genuine, serious intrusion.
That does not make medical and psychiatric records open season. A PI plaintiff who puts her physical condition at issue waives privacy as to records relevant to the injuries claimed, but not as to unrelated conditions — courts routinely limit subpoenas to the body parts and time periods the complaint actually describes. When you draft the records request, anticipate the balancing: tie each category to a pleaded injury, cabin the date range, and you leave the objecting party far less to work with. The same discipline pays off when the records bear on damages tied to liens and prior treatment, the sort of documentation that drives the negotiation discussed in our analysis of ERISA lien reduction in PI settlements.
Moving to compel — and the mirror motion to quash
When a custodian refuses or produces a partial file, your remedy is a motion to compel compliance with the deposition subpoena under Code of Civil Procedure section 2025.480. The motion has to be made within 60 days of the record of the deposition's completion — for a records subpoena, that generally runs from the custodian's production or refusal — and it carries a mandatory meet-and-confer obligation. Skipping the meet-and-confer, or filing late, gives the court an easy off-ramp that has nothing to do with whether you were entitled to the records.
The objecting side's instrument is the motion to quash or modify under section 1987.1, which lets the court quash, modify, or issue a protective order on a subpoena, and condition production on terms the court finds just. A consumer who received a section 1985.3 notice uses this vehicle, as does a nonparty custodian burdened by an overbroad demand. Expect it most often when you subpoena a retained expert's entire file and fee history — a request that is squarely proper, but one the defense will try to narrow. Keep that fight in view when you build the record for a causation challenge, because the expert's own documents frequently decide the gatekeeping question we examine in our review of tightening Daubert causation standards.
Court-side enforcement when a nonparty simply ignores you
A nonparty who disobeys a properly served subpoena is not merely uncooperative — it is in contempt. Section 2020.240 makes a custodian who fails to obey a business-records subpoena subject to the court's contempt power and liable for up to $500 plus the damages the aggrieved party sustains. For subpoenas generally, section 1987.2 authorizes the court to award the expenses, including attorney fees, incurred in making or opposing a motion to compel or to quash, where the losing side acted without substantial justification.
Those fee provisions change the economics of the fight. A custodian stonewalling on a clean subpoena, or an opposing party running a meritless motion to quash to delay, is exposed to a fee award that often exceeds what the discovery dispute is worth to them. When you move to compel, ask for the fees; when you defeat a baseless motion to quash, ask again. Courts in these disputes are more willing to shift costs against a nonparty or an obstructing party than many practitioners assume, and the sanctions record you build early tends to discipline behavior through the rest of the case. The misuse-of-discovery catalog in section 2023.010 gives the court a further basis where the obstruction is part of a pattern.
Practice points that save the subpoena
Three habits prevent most of the failures above. First, calendar the production date backward from the day you serve, counting the section 2020.410 minimums and the section 1985.3 or 1985.6 notice window separately, and never let the production date fall inside either. Second, draft categories that map to pleaded injuries and a defined time frame, so a privacy objection has nowhere to land after Williams. Third, serve proof of the consumer or employee notice on the custodian, because a custodian without that proof is right to refuse, and the refusal is your fault, not theirs. These same records often fix the value of a claim before any motion is filed — the kind of documentation that controls recovery analysis in a UIM-only settlement after arbitration.
Third-party discovery rewards procedure. The attorney who serves a tight, correctly noticed subpoena, meets and confers in writing, and asks for fees on the motion will get the records and often get them faster than the one who fights over relevance. The statutes are not obstacles to the file you need; read in order, they are the route to it.