California doesn’t have a single standardized mold disclosure form for rentals. Instead, residential landlords meet their obligation with two pieces of paper: the state-published booklet “Information on Dampness and Mold for Renters in California,” which every prospective tenant must receive before signing a lease, and, when you know a unit has a mold problem, a written disclosure attached to the lease describing what you know. This guide walks through what each document is, what to write on it, and how to record delivery so the tenant can’t later say they were never told.
The Mold Booklet Every California Landlord Must Provide
Health and Safety Code section 26148 requires residential landlords to give prospective tenants a copy of the CDPH consumer booklet “Information on Dampness and Mold for Renters in California” before the tenant signs the lease or rental agreement.1California Legislative Information. California Health and Safety Code 26148 The requirement has been active since January 1, 2022, when CDPH finalized the booklet.2California Department of Public Health. Information on Dampness and Mold for Renters in California The California Apartment Association has incorporated it into its standard rental agreement.3California Department of Public Health. Mold
The booklet covers how to identify mold, what causes it, steps tenants and landlords should take to address it, and the health effects of exposure. You do not fill anything out on the booklet itself. Your job is simpler:
- Download the current version from CDPH in English or Spanish, whichever your tenant reads.
- Include it in the lease packet you present before signing.
- Add a receipt acknowledgment. This can be a clause in the lease reading something like “Tenant acknowledges receipt of the CDPH booklet ‘Information on Dampness and Mold for Renters in California,'” or a separate signature page attached as an addendum.
- Keep the signed copy in your file.
That is the entire mandatory step. Every new tenancy gets a booklet and a signed acknowledgment, regardless of whether the unit has ever had a mold issue.
When You Also Need a Written Mold Disclosure
The Toxic Mold Protection Act includes a second, more detailed disclosure requirement in Health and Safety Code section 26147. It would obligate landlords who know or have reason to believe mold is present at levels exceeding exposure limits or posing a health threat to disclose that in writing to prospective tenants before lease signing, and to existing tenants as soon as reasonably practical.4California Legislative Information. California Health and Safety Code 26147
Section 26147(e) puts that requirement on hold until CDPH adopts the exposure standards and remediation guidelines the Act references. CDPH has not done so. Its own guidance states that “science-based exposure limits for indoor molds cannot be established at this time, and none exist in California.”5California Department of Public Health. Frequently Asked Questions about Mold So the specific statutory disclosure in 26147 is technically dormant.
That does not free you from disclosing known mold. California landlords still owe a general duty to maintain habitable premises and to disclose known hazardous conditions. If you know a unit has a significant mold problem, silence is a bad legal position no matter what section 26147 says. A written disclosure attached to the lease protects you against later claims of concealment. Many landlords use the California Association of Realtors’ Lease/Rental Mold and Ventilation Addendum for this purpose; a plain-language letter attached as a lease exhibit works as well, provided it captures the specifics below.
What to Put on the Written Disclosure
Whether you use the CAR addendum or draft your own document, cover each of these fields. Vague answers like “some mold was found and fixed” invite disputes. Specifics create the paper trail that protects you.
- Location and extent. Where the mold was found (for example, behind bathroom drywall or under kitchen cabinetry) and roughly how much surface area was affected.
- Moisture source. The underlying cause: pipe leak, roof failure, condensation from poor ventilation, flooding, or another source.
- Discovery date. When you first observed the mold or received a report about it.
- Testing results. If a licensed industrial hygienist did air or surface sampling, attach the lab report or its executive summary, including species if identified.
- Remediation work. What was done, the remediation company’s name, the completion date, and whether a clearance test confirmed successful removal.
- Ongoing conditions. Whether the moisture source is permanently fixed or whether the area remains prone to recurring dampness.
If you hired a remediation firm, attach the invoice and clearance report. Those documents are the strongest evidence you handled the problem responsibly. Look for a company that follows the ANSI/IICRC S520 standard, which defines containment, pressure management, protective equipment, and documentation practices for safe mold removal. A clearance report from an S520-compliant firm carries considerably more weight than an informal note that a spot got scrubbed.
Scale matters when deciding whether professional remediation is called for. The EPA suggests a homeowner can typically clean a moldy patch smaller than roughly 10 square feet, or a 3-by-3-foot area; anything larger warrants a professional.6US EPA. A Brief Guide to Mold, Moisture and Your Home A prospective tenant reading your disclosure will have more confidence in a professional remediation than in a self-cleanup, and that is worth factoring into how you handle any significant problem.
How to Deliver and Record the Paperwork
Both documents belong in the lease packet the tenant receives before signing. Handle them the same way:
- Attach the CDPH booklet as a lease exhibit and include a signed acknowledgment of receipt.
- Attach any written mold disclosure as a second lease exhibit with its own signature line.
- Have the tenant sign at lease signing, not later.
- Give the tenant a full copy of the executed packet and keep the original for your files.
For an existing tenant who is not renewing but for whom a mold issue has come to light, deliver the written disclosure through a traceable method (email with read receipt, certified mail, or a digital signature platform) and keep the delivery record with the disclosure itself.
Retain signed copies for at least three years after the tenancy ends. Longer is safer. If a former tenant claims years later that you never disclosed a mold condition, the signed acknowledgment is the document that ends the argument.
Preventing the Next Disclosure
The simplest way to avoid disclosing mold is to keep it from developing. The EPA identifies moisture control as the single most important factor: water-damaged areas and materials must be dried within 24 to 48 hours to prevent mold growth.6US EPA. A Brief Guide to Mold, Moisture and Your Home In bathrooms and other rooms prone to dampness, run an exhaust fan or open a window and clean surfaces regularly.
If mold appears and you clean it up without fixing the water source, it will come back. Remediation that removes visible growth but leaves a leaking pipe or a poorly ventilated bathroom in place puts you right back into disclosure territory at the next lease. Fix the source first, then clean the mold, then document the work. That order protects the building and your legal position at the same time.