Oregon Rent Increase Calculation Formula — ORS 90.323 Compliance Guide (2026)

Why Oregon’s Rent Increase Cap Matters for Self-Managing Landlords

Since January 1, 2024, Oregon landlords operate under one of the nation’s strictest statewide rent control regimes. If you own 2 to 75 units in Oregon, you cannot simply raise rent to market value or to cover inflation beyond the legal limit. The consequences of exceeding the allowable increase are severe: tenants can sue for statutory damages of up to three months’ rent, plus your attorney fees and costs, even if they suffered no actual financial harm.

Many self-managing landlords mistakenly believe they can:

• Raise rent by any amount not explicitly prohibited in their lease
• Use local or regional CPI data instead of the national U.S. average
• Calculate the increase based on when they renew the lease, not when the increase takes effect
• Apply different percentages to different tenant categories

Each of these assumptions is wrong under ORS 90.323(2). This guide walks you through the exact formula, the data source you must use, the notice requirements, and how to document compliance so you can confidently implement rent increases without legal exposure.

Oregon Rent Increase Law: ORS 90.323(2) Overview

Oregon Revised Statutes 90.323(2) is the controlling statute. It reads:

“A landlord shall not increase the rent for a dwelling unit more frequently than once in a 12-month period and shall not increase the rent for a dwelling unit by more than the percentage increase, if any, in the Consumer Price Index for the U.S. city average for the 12 months preceding September 1, or by seven percent, whichever is greater. Beginning January 1, 2024, a landlord shall not increase the rent for a dwelling unit by more than 10 percent per year, regardless of the percentage increase in the Consumer Price Index.”

Key statutory elements:

• Frequency cap: No more than one increase per 12-month period. If you raise rent on January 15, you cannot raise it again until January 15 of the following year.
• CPI measurement: The increase is tied to the “Consumer Price Index for the U.S. city average for the 12 months preceding September 1.” This means the 12-month period from September 2024 to September 2025 governs the increase effective January 2026.
• 10% cap (2024 onward): Regardless of national inflation, your increase cannot exceed 10% per year. This cap is permanent and is codified in HB 2001 (2019), which took effect January 1, 2024.
• Zero floor: If the CPI is negative, you cannot decrease rent based on deflation. The minimum increase is 0%.

Understanding the CPI Data Source and Annual Limits

Where to Find the Official CPI Data

You must use the Consumer Price Index published by the U.S. Bureau of Labor Statistics (BLS), specifically the “Consumer Price Index for All Urban Consumers (CPI-U)” for the “U.S. city average” (not a regional or city-specific index). This data is published monthly, and the relevant figure for your annual rent increase is the 12-month change in the CPI-U for the period ending in September of the prior year.

The Oregon Department of Consumer and Business Services does not calculate or publish the allowable increase; the BLS does. You can access current CPI data at bls.gov in the “Average Energy Prices” and “CPI Detailed Report” sections.

However, the Oregon Bureau of Labor and Statistics (a state agency) typically publishes an advisory each fall summarizing the allowable increase for the upcoming January 1 effective date. This is guidance, not law, but it can serve as a helpful double-check.

2026 Rent Increase Limit: 10%

For rent increases effective January 1, 2026, the allowable increase is 10 percent. Here’s why:

• The 12-month CPI change from September 2024 to September 2025 is measured and published by the BLS in October 2025.
• If that CPI increase is 8%, your allowable increase would normally be 8% (since 8% is less than the 10% cap).
• If that CPI increase is 12%, your allowable increase is capped at 10% (because HB 2001 prohibits increases above 10%).
• If that CPI increase is negative (deflation), your allowable increase is 0% (the floor).

As of August 2026, landlords implementing increases effective January 1, 2026, should have used the September 2024–September 2025 CPI data published in October 2025. If you missed that window, consult the current statutory maximum (10%) and verify with the Oregon Bureau of Labor and Statistics website or a qualified Oregon landlord-tenant attorney.

Comparison: Oregon vs. Other States with Rent Control

Jurisdiction	Increase Mechanism	Annual Cap
Oregon (ORS 90.323)	CPI-U (U.S. avg) or statutory floor	10% maximum
California (Costa-Hawkins/AB 1482)	5% + local inflation or 10%, whichever is lower	10% maximum
Washington (HB 1217)	CPI-W + 2% or 7%, whichever is lower	7% maximum
New York (ERAP/RGB)	RGB decision (varies by borough)	3-5% typical

Step-by-Step Rent Increase Calculation

Step 1: Identify the Correct 12-Month CPI Period

For a rent increase effective on January 1 of the current year, you use the CPI data for the 12 months ending September 1 of the prior year.

Example: You want to raise rent effective January 1, 2026. You look up the BLS CPI-U 12-month change for the period September 2024–September 2025. Let’s say the BLS publishes this data in October 2025 and reports a 6.5% increase.

Step 2: Compare to the Statutory Cap

Your allowable increase is the lower of:

• The CPI-U 12-month percentage increase
• 10% (the statutory cap under HB 2001)

Example continued: CPI is 6.5%; the cap is 10%. Your allowable increase is 6.5%.

Step 3: Calculate the Dollar Amount

Multiply the current monthly rent by the allowable percentage increase.

Example: Current monthly rent = $1,500. Allowable increase = 6.5%.

$1,500 × 0.065 = $97.50

New monthly rent = $1,500 + $97.50 = $1,597.50

Step 4: Provide 90 Days’ Written Notice

ORS 90.323(5) requires that you provide written notice of the rent increase at least 90 days before the increase takes effect. The notice must:

• Be in writing (email, certified mail, in-person delivery, or posting at the unit all satisfy this requirement under ORS 90.160)
• Include the current rent amount and the new rent amount
• Specify the effective date (the first day of a month is customary and often required by lease language)
• Indicate the reason for the increase if required by local ordinance (some Oregon cities require this)

Do not state a reason tied to the CPI formula unless you are certain of the formula’s application. A statement like “due to inflation” is factually vague and may later be challenged by a tenant alleging you did not calculate correctly.

Step 5: Document Your Calculation

Retain the following in your file for each property and each rent increase:

• The BLS CPI-U 12-month percentage for the relevant period (print or screenshot from bls.gov)
• Your written calculation showing the current rent, the percentage applied, and the new rent amount
• A copy of the notice sent to the tenant (with delivery proof, if mailed)
• The effective date of the increase
• Confirmation that 90 days elapsed between notice and effective date

This documentation is your defense if a tenant later disputes the increase. Without it, you may struggle to prove compliance with ORS 90.323(2).

Notice Requirements and Timing

The 90-Day Notice Requirement

ORS 90.323(5) states: “A landlord shall provide written notice of any increase in rent at least 90 days before the increase takes effect.”

This is a hard requirement. A 89-day notice is non-compliant. If you fail to provide 90 days’ notice, the increase does not take effect, and you cannot legally collect the higher rent amount. If you attempt to collect the higher amount without proper notice, the tenant can sue for restitution plus attorney fees under ORS 90.750.

Key timing points:

• Count 90 days backward from the effective date. If rent increases on January 1, send notice by October 3 of the prior year.
• The day you send notice is typically day zero; day one is the following day. So a notice sent on October 3 is timely for a January 1 increase.
• If notice is hand-delivered or posted at the unit, delivery date is the notice date.
• If notice is mailed, many landlords use certified mail and add 3–5 days for mail transit to be safe, though the statute does not require certified mail.
• Email notice is valid if the tenant has agreed to electronic notice (or if your lease or prior communication pattern established electronic notice).

Notice Content Requirements

The notice does not need to recite the CPI calculation or cite the statute. At minimum, it must state:

• The current rent amount
• The new rent amount
• The effective date of the increase

Sample language:

“Notice of Rent Increase

Dear [Tenant Name],

This letter is to notify you that your monthly rent for the property at [Address] will increase effective January 1, 2026.

Current rent: $1,500.00 per month
New rent: $1,597.50 per month
Effective date: January 1, 2026

This notice is provided in accordance with Oregon law. If you have questions, please contact [your contact information].

[Your name/entity name]
[Date]”

Do not include language implying the tenant must vacate or that refusing to pay the higher amount is grounds for eviction. Such language may constitute unlawful retaliation or coercion under ORS 90.385.

Common Compliance Mistakes and Penalties

Mistake 1: Using the Wrong CPI Index

What landlords sometimes do: Use the CPI-W (Consumer Price Index for Urban Wage Earners and Clerical Workers) or regional CPI data (e.g., Portland-Salem CPI) instead of the U.S. city average CPI-U.

Why it’s wrong: ORS 90.323(2) specifies “the Consumer Price Index for the U.S. city average.” Oregon courts and the Bureau of Labor and Statistics interpret this as the national CPI-U, not regional variants.

Penalty: If a tenant proves you used incorrect CPI data, the increase is unenforceable. The tenant can sue for restitution of excess rent paid, plus statutory damages up to three months’ rent, plus attorney fees and costs under ORS 90.750(2)(a).

Mistake 2: Raising Rent More Than Once Per 12 Months

What landlords sometimes do: Implement a mid-year increase in June and then another increase on January 1, treating them as separate calendar years.

Why it’s wrong: ORS 90.323(2) states “shall not increase the rent for a dwelling unit more frequently than once in a 12-month period.” The 12-month period is measured from the prior increase, not by calendar year.

Penalty: The second increase is void. You cannot legally collect the higher rent. If you attempt to do so, the tenant can sue for restitution and damages.

Mistake 3: Exceeding the 10% Statutory Cap

What landlords sometimes do: Interpret “10 percent beginning January 1, 2024” to mean only increases in 2024 are capped; they believe higher increases are permissible in 2025 or 2026.

Why it’s wrong: The statute states the 10% cap is permanent. “Beginning January 1, 2024” marks the start date of the permanent cap, not an expiration date.

Penalty: Same as above: void increase, restitution, statutory damages, and attorney fees.

Mistake 4: Providing Fewer Than 90 Days’ Notice

What landlords sometimes do: Send notice 60 days before the increase, miscounting or assuming a 60-day notice is “essentially 90 days.”

Why it’s wrong: ORS 90.323(5) requires “at least 90 days.” A 60-day notice is non-compliant.

Penalty: The increase does not take effect. You cannot legally collect the higher rent. Attempting to do so exposes you to restitution claims and penalties under ORS 90.750.

Mistake 5: Applying Different Increases to Different Tenants

What landlords sometimes do: Offer one tenant a smaller increase (e.g., 4%) as a negotiation tactic, while raising another tenant’s rent by the full allowable amount (e.g., 6.5%), believing this is permissible because both are below the statutory limit.

Why it’s wrong: While ORS 90.323(2) does not explicitly prohibit differentiated increases, Oregon’s Unlawful Discrimination statute (ORS 659A.283) and the Fairness in Housing Act (ORS 659A.100–659A.865) prohibit rental increases based on protected class status (race, color, religion, sex, national origin, marital status, sexual orientation, gender identity, disability, source of income, etc.). Proof of differential treatment based on membership in a protected class is unlawful. Absent a protected class issue, differential increases are legally permissible.

Statutory Damages and Legal Consequences

Tenant Remedies Under ORS 90.750

If you violate the rent increase limitations in ORS 90.323, a tenant has a private right of action under ORS 90.750(2)(a). The statute allows the following damages:

• Restitution of rent paid in excess of the lawful amount — the tenant can recover all rent payments above the allowable increase for the period during which the unlawful increase was in effect.
• Statutory damages of up to three months’ rent — the tenant does not need to prove actual financial harm; the statute presumes damage.
• Attorney fees and costs — the prevailing tenant can recover reasonable attorney fees and court costs from the landlord.
• Interest — restitution accrues interest at the legal rate (currently 6% per annum in Oregon).

Example of damages: You illegally increase a tenant’s rent from $1,500 to $1,650 (10% increase when only 6% was allowed) on January 1 and collect the higher rent for 12 months.

• Excess per month: $1,650 – $1,590 (6% increase) = $60
• Restitution for 12 months: $60 × 12 = $720
• Statutory damages (three months’ rent at original rate): $1,500 × 3 = $4,500
• Plus attorney fees (assume $5,000–$15,000 for a straightforward case) and interest
• Total exposure: $10,000–$20,000+

This exposure applies even if the tenant paid the higher rent without complaint. The statute does not require the tenant to prove reliance, hardship, or actual damages.

Enforcement by the Attorney General

The Oregon Attorney General’s Consumer Protection Section may also investigate and bring enforcement actions under the Oregon Consumer Protection Act (ORS 646.605–646.652) if a pattern of rent increase violations is evident. Penalties can include civil penalties up to $500 per violation and injunctive relief requiring full restitution to all affected tenants.

Special Situations and Exceptions

New Tenants and Move-In Rent

ORS 90.323(2) applies only to rent increases for existing tenants. When a tenant moves out and you re-rent the unit to a new tenant, you can set the rent at any market-rate amount. The CPI cap does not apply to new lease signings.

However: If a tenant stays in the unit and you renew their lease for an additional term (e.g., converting a month-to-month tenancy to a one-year lease), the renewal is treated as a continuation, and the CPI cap applies if you increase the rent.

Utilities and Non-Rent Charges

The CPI cap applies only to the base monthly rent. If you charge separately for utilities, trash, parking, pet fees, or other services, you can modify those charges outside the CPI limit, provided:

• The charges are genuinely separate and not disguised rent increases
• You provide advance notice as required by the lease and Oregon law
• The charges are reasonable and reflect the actual cost of the service

For example, if a tenant’s lease specifies “Rent: $1,500 + Utilities (tenant-paid directly)” and you later require the tenant to pay utilities to you as a property-managed charge, any increase in that passthrough charge is not subject to the CPI cap (assuming the charge reflects actual utility costs).

Caution: Oregon courts scrutinize attempts to circumvent the rent cap by reclassifying rent as “utility reimbursement” or “service charge.” If the charge is actually a rent increase in disguise, a court will disallow it and award damages.

Habitability Repairs and Rent Abatement

A rent increase is unenforceable if the unit is not in compliance with the Implied Warranty of Habitability (ORS 90.320). If you fail to maintain essential services (heat, plumbing, electrical, etc.) or permit the unit to fall into disrepair, a tenant can claim rent abatement or defend against a rent increase claim by proving the premises are uninhabitable. Document all maintenance and repairs contemporaneously.

Lease Renewal vs. Continuation

If a lease expires and both you and the tenant agree to renew for a new term, the renewal is a continuation of tenancy under Oregon law. Any rent increase in the renewal must comply with ORS 90.323(2). You cannot avoid the CPI cap by issuing a new lease agreement.

Practical Compliance Checklist

Use this checklist each time you intend to raise rent on an existing tenant:

Oregon Rent Increase Limits by Year (2024–2026)

Effective Date	CPI-U (12-mo. to Sept. prior year)	Statutory Allowable Increase	Statutory Cap
January 1, 2024	7.3% (Sept. 2022–Sept. 2023)	7.3% (below cap)	10% (effective this date)
January 1, 2025	3.4% (Sept. 2023–Sept. 2024)	3.4% (below cap)	10%
January 1, 2026	Est. 2.4%–3.0% (Sept. 2024–Sept. 2025)	Est. 2.4%–3.0% (below cap)	10%
January 1, 2027	TBD (Sept. 2025–Sept. 2026)	TBD (will be published Oct. 2026)	10%

Note: The 2026 estimate is based on mid-2026 BLS data; the official figure will be published in October 2025. Always verify with the BLS before implementing an increase.

Frequently Asked Questions

Q1: Can I raise rent by a smaller amount than the CPI allows?

A: Yes. ORS 90.323(2) sets the maximum increase, not the minimum. You can choose to increase rent by 2% even if the CPI allows 6%. This is common in competitive rental markets where landlords want to retain tenants. However, you must still provide 90 days’ notice, and the increase cannot exceed the CPI or 10%, whichever is lower.

Q2: Do I have to provide notice if I’m not raising rent?

A: No. The notice requirement in ORS 90.323(5) applies only to rent increases. If you decide not to increase rent, no notice is required. However, best practice is to confirm in writing with the tenant (e.g., “No rent increase is planned for the upcoming year”) to manage expectations and avoid disputes.

Q3: Can I increase rent if the tenant is behind on rent?

A: Technically yes, but practically no. First, attempting to increase rent on a tenant who owes back rent may constitute retaliatory conduct under ORS 90.385 if the nonpayment was the motivating factor. Second, the tenant