Oregon Rent Increase Calculation & CPI Limits — Compliance Guide (2026)

Oregon's CPI-Based Rent Increase System: What It Means for Your Portfolio

Unlike California's statewide 3% cap or Washington's variable local limits, Oregon's rent increase rules operate under a federal formula: the Consumer Price Index for All Urban Consumers (CPI-U) published by the U.S. Bureau of Labor Statistics. This means your allowable rent increase isn't set by the legislature or city council. It's determined by national inflation data tied to a specific geographic region.

For standard rental properties (apartments, houses, condos), ORS 90.323(2) states the maximum rent increase shall not exceed the percentage increase in the Consumer Price Index for All Urban Consumers (CPI-U) for the Portland-Seattle-Tacoma metropolitan area, as published by the Bureau of Labor Statistics.

Self-managing landlords with 2–75 units need to understand three critical components:

1. How to identify the correct CPI-U figure for your notice period
2. How to calculate the dollar amount increase correctly
3. How to deliver the notice within the 90-day requirement without losing the increase

Mistakes in any of these areas can render your increase unenforceable and expose you to tenant claims.

The Legal Source: ORS 90.323(2) and Its Strict Requirements

Oregon Revised Statute 90.323(2) is the foundational rule. Here's the exact language that governs your actions:

"A landlord may not increase rent unless the landlord gives the tenant a written notice of the increase 90 days before the increase is to take effect. The amount of increase in rent shall not exceed the percentage increase in the Consumer Price Index for All Urban Consumers (CPI-U) for the Portland-Seattle-Tacoma metropolitan area, as published by the Bureau of Labor Statistics for the most recent 12-month period ending August 31."

Three operative facts emerge from this statute:

• 90-day notice requirement is mandatory — not 60 days, not 30 days, not 45 days. Ninety days means the increase cannot take effect until 91 days after delivery of written notice.
• The CPI-U figure is fixed annually on August 31 — the BLS publishes its 12-month CPI-U data in early September each year, and that figure controls increases effective through the following September.
• The percentage limit is absolute — you cannot increase by more than the published CPI-U percentage, even if your mortgage, taxes, or insurance rose faster.

Courts have interpreted this as a strict-liability rule. Intent doesn't matter. If your notice said 3% when the CPI limit was 2.6%, the excess 0.4% is illegal, and you're liable for the difference plus damages.

The 2026 CPI-U Limit: Current Figure and How It Applies

For rent increases effective between September 1, 2025, and August 31, 2026, the allowable increase is 2.6%, based on the 12-month CPI-U ending August 31, 2025.

This means:

• A tenant currently paying $1,500/month can legally be asked to pay no more than $1,539 (2.6% increase)
• A $2,000/month unit has a maximum increase of $52 (2.6%)
• A $2,500/month unit has a maximum increase of $65 (2.6%)

Starting September 1, 2026, Oregon will use the new CPI-U figure (for the 12-month period ending August 31, 2026) to set limits for increases effective September 2026 through August 2027. The BLS publishes this data in the first week of October each year.

To plan ahead for 2027, watch for the October 2026 CPI-U release. If you intend to raise rent effective December 1, 2026, you'll need to send notice by September 1, 2026—before the new CPI figure is public. In this scenario, you must use the 2.6% figure (the current limit through August 31, 2026).

Step-by-Step: Calculating the Exact Dollar Increase

Here's where landlords often make compliance errors. The calculation must be precise because tenants and their attorneys will audit it.

Step 1: Confirm the current rent amount. Use the base rent only—not deposits, fees, or utilities the tenant pays separately. If the lease specifies $1,650/month, that's your starting point.

Step 2: Multiply current rent by the CPI-U percentage (2.6% for 2026).

Example:

Current rent: $1,650

CPI-U increase: 2.6%

Calculation: $1,650 × 0.026 = $42.90

Step 3: Add the increase to the current rent.

$1,650 + $42.90 = $1,692.90

Step 4: Round according to your lease or standard practice. Oregon law doesn't mandate rounding, but many landlords round to the nearest dollar ($1,693) or keep cents. Whatever you choose, apply it consistently across your portfolio. Selective rounding for individual tenants opens you to discrimination claims.

Step 5: Document your calculation in writing. Keep records showing:

• The prior rent amount

• The CPI-U percentage used

• The calculation (rent × percentage)

• The new rent amount

• The effective date of the increase

• The date of notice delivery

If a tenant disputes the increase, you'll need to prove the math was legal. A simple spreadsheet or saved email showing your work will defend you far better than a verbal explanation.

The 90-Day Notice Requirement: Timing and Delivery Methods

ORS 90.323(2) requires written notice at least 90 days before the increase is to take effect. This is not a suggestion; it's a statutory floor. Courts have been clear: if the effective date is fewer than 90 days after notice delivery, the increase is void.

Counting the 90 days: Start counting on the day the tenant receives the notice (not the day you send it). If you email notice on June 1 and the tenant opens it that day, day 1 is June 1. Day 90 is August 30. The earliest effective date is September 1 (day 91).

Acceptable delivery methods under ORS 90.305:

• Hand delivery to the tenant (get a signature or note the date and time)
• Certified mail, return receipt requested (receipt proves delivery date)
• Regular first-class mail addressed to the tenant at the rental premises (legally presumed delivered 3 days after posting, per ORS 90.007)
• Email, if the lease permits or the tenant has previously agreed to email service
• Text message or app notification, if the lease explicitly provides for this method

Best practice for compliance: Use certified mail with return receipt. The USPS receipt is your proof of delivery date, and it creates a documentary record. If a tenant later claims they didn't receive notice, the certified mail receipt defeats that argument in court.

Email is faster but creates ambiguity about receipt. If you email, send it from an account you check regularly, and consider requesting a read receipt. However, read receipts are not legally equivalent to certified mail delivery proof.

Do not rely on leaving notice under the door, taping it to a window, or leaving it with a roommate unless the lease explicitly permits it. Oregon courts have found such methods insufficient when challenged.

Common Compliance Pitfalls That Landlords Make

Pitfall 1: Using an outdated CPI-U figure

A landlord in Portland sends a notice in January 2026 stating a 3.5% increase, using CPI-U data from an earlier year. The current limit is 2.6%. The tenant's attorney files a claim for the excess 0.9% plus damages. The landlord loses because they used the wrong figure available at the time of notice.

Fix: Before sending any rent increase notice, confirm the active CPI-U limit. The BLS publishes data at bls.gov/cpi. Oregon's Attorney General also maintains guidance on the current figure.

Pitfall 2: Miscalculating rounding or cents

A landlord calculates a 2.6% increase on $2,150: $2,150 × 0.026 = $55.90. They round up to $60 to simplify. A tenant pays $55 extra per month for a year ($660), then disputes the $5/month overage. The tenant is entitled to a refund of the overage plus damages.

Fix: Calculate precisely, round consistently (always up, always down, or to nearest dollar), and document your rounding rule. Apply it uniformly across all tenants.

Pitfall 3: Delivering notice fewer than 90 days before the effective date

A landlord sends notice on June 15, 2026, stating an effective increase date of August 15, 2026 (61 days). The increase is void. The tenant can refuse to pay the increase, and if the landlord tries to evict for non-payment, the eviction will fail because the increase was never lawful.

Fix: Create a calendar. Mark the effective date first. Count backward 90 days. Send notice by that date. If today is June 16 and you want the increase to start August 15, you've missed the 90-day window (you needed to send notice by May 17).

Pitfall 4: Failing to provide written notice

A landlord calls or texts the tenant verbally announcing a rent increase. Oregon law requires written notice. Verbal notice is not compliant, even if the tenant acknowledges hearing it.

Fix: Always deliver rent increase notices in writing—email, certified mail, or hand-delivered with a signed receipt.

Pitfall 5: Including non-rent charges in the "base rent" calculation

A landlord states the rent is $1,500, but includes $200 for utilities the tenant pays. The CPI-U increase is calculated on $1,700. When the utility portion increases separately, the tenant is charged compounded increases. This violates the spirit of ORS 90.323(2) and courts have found it problematic.

Fix: Use only the base rent (excluding utilities, parking, pet fees, or other pass-through costs) in the CPI-U calculation. If utilities are included in rent, treat that combined amount as the base. If utilities are separate, increase them only if the lease permits and you've given separate 90-day notice for that increase.

Mobile Home Parks: Different Rules Under ORS 90.427

If you own a mobile home park in Oregon, do not use the standard ORS 90.323(2) rule. Mobile home parks (also called manufactured dwelling parks) have their own rent increase limits under ORS 90.427.

ORS 90.427 uses a different CPI calculation and allows increases of:

• The percentage increase in the Consumer Price Index-Urban (same CPI-U), or
• 7%, whichever is less

This means a mobile home park landlord can raise rent by up to 7% regardless of CPI in years when CPI is higher. Conversely, in low-inflation years, you're capped at the CPI figure (currently 2.6%).

Mobile home parks also have additional requirements:

• 120 days' notice (not 90 days)
• Written notice stating the basis for the increase and the effective date
• Specific language disclosures under ORS 90.427(3)

If you manage mobile home parks, verify each unit's status before applying rent increase rules. A property listed as a "mobile home park" triggers ORS 90.427, not ORS 90.323(2).

Penalties for Non-Compliance: What Violations Cost

Oregon landlord-tenant law is strict about enforcement. Violations of rent increase requirements create automatic liability.

Actual damages: If you increase rent beyond the CPI-U limit, the tenant can recover the excess amount, plus interest at the rate of 9% per annum from the date of overpayment. A tenant who paid $100/month extra for 12 months would recover $1,200 in overpaid rent plus 9% interest.

Statutory damages: Under ORS 90.405, a landlord who violates rent increase requirements is liable for statutory damages of up to $250 per violation, or the actual damages, whichever is greater. A single improper rent increase notice can trigger one violation claim. If the tenant remains in possession and you attempt to collect the illegal increase over multiple months, that can be viewed as multiple violations.

Attorney fees: ORS 90.405 requires that a prevailing tenant (or landlord, if the tenant violates the statute) recover attorney fees. This means if a tenant sues and wins, you pay their attorney fees in addition to damages. Attorney fees in Oregon landlord-tenant cases typically range from $2,000 to $10,000+, depending on case complexity.

Interest on judgments: Judgments also accrue interest at Oregon's post-judgment rate (currently 9% annually) until paid.

Eviction defense: If you attempt to evict a tenant for non-payment based on an illegal rent increase, the tenant has a complete defense. The eviction will be dismissed, and you may owe the tenant damages for bringing a frivolous case.

Example scenario: You increase a tenant's rent from $1,500 to $1,600 (6.7%) in 2026 when the CPI limit is 2.6%. The tenant refuses to pay the extra $100/month. You serve a 3-day pay-or-quit notice. The tenant doesn't pay and you file for eviction. At trial, the tenant's attorney proves the increase was illegal. The court dismisses the eviction. You now owe the tenant:

• $1,200 in overpaid rent (12 months × $100)
• 9% interest on that amount ($108 over one year)
• Statutory damages up to $250
• The tenant's attorney fees ($3,000–$8,000)
• Your own attorney fees are not recoverable (only the prevailing party recovers fees)

Total exposure: $4,500–$9,500 on a single property, plus reputational damage.

Recent Changes and 2026 Updates

Oregon's rent increase law has remained stable since ORS 90.323 was amended in 2019 to adopt the CPI-U formula. However, several developments have affected enforcement:

2024 Guidance from Oregon Attorney General: The Attorney General's office issued clarification in early 2024 that landlords using outdated CPI-U figures or failing to update annually can face investigation for unfair or deceptive trade practices under ORS 646.605. This added a regulatory enforcement layer beyond civil private lawsuits.

Increased tenant litigation: Legal aid organizations in Oregon (notably Community Alliance of Tenants) have begun offering free rent increase audits to tenants. This has increased the volume of claims from organized tenants and legal advocates, not just individual disputes.

Rounding transparency: Several Oregon courts have noted that landlords must disclose their rounding methodology in writing if challenged. Unwritten rounding rules are not enforceable. If you round, document it in your lease or a policy provided to all tenants.

CPI data delays: The BLS occasionally delays CPI-U publication due to government shutdowns or data corrections. Landlords who send notices before new CPI data is released must use the prior year's figure. Plan rent increase campaigns with this uncertainty in mind.

Using Compliance Technology to Automate Rent Increase Calculations

For self-managing landlords with multiple units, manual calculation and notice delivery creates significant compliance risk. A single data entry error or delivery mistake across 20 or 30 units exposes you to multiple damage claims.

Automated compliance tools can:

• Automatically pull current CPI-U data from the BLS and alert you when annual figures update
• Calculate the exact allowable increase for each unit based on current rent, rounding rules, and CPI-U
• Generate pre-filled rent increase notices with correct dates and percentages
• Track notice delivery dates and effective dates in a centralized log
• Flag calculations that exceed the legal limit before you send them
• Create audit trails showing all rent increase decisions and delivery records

LeaseBase's compliance engine monitors Oregon CPI-U changes year-round and alerts you when the August 31 figure is published. You can review suggested increase amounts for each unit, approve or adjust them, and generate compliant notices for bulk delivery. The system tracks delivery and effective dates, reducing the risk of missed 90-day deadlines.

For a portfolio of 10–75 units, this type of automation typically saves 5–10 hours per rent increase cycle and virtually eliminates calculation errors.

Step-by-Step Compliance Checklist for Rent Increases

Before sending any rent increase notice:

Confirm the current CPI-U limit for Portland-Seattle-Tacoma (check bls.gov/cpi or Oregon Attorney General guidance)

Verify the tenant's current rent amount from your lease and payment records

Calculate the allowable increase: current rent × CPI-U percentage

Document your rounding rule in writing

Determine the intended effective date (must be at least 90 days after notice delivery)

Count backward 90 days to identify the latest date you can deliver notice

Draft the rent increase notice in writing, including:
– Current rent amount
– New rent amount
– The CPI-U percentage used and basis for calculation
– Effective date
– Date notice was delivered
– Tenant's name, unit number, and address

Select a compliant delivery method (certified mail recommended)

Deliver the notice on or before the 90-day deadline date

Retain proof of delivery (USPS receipt, signed receipt, email confirmation)

File the notice and proof of delivery in a secure compliance folder or system

Update your rent roll to reflect the new rate effective on the stated date

After the increase takes effect:

Confirm the tenant is paying the new amount

Update your lease or addendum to reflect the new rent in writing

Retain the signed acknowledgment or lease amendment

Reconcile your rent income records to match the new amount

Maintain the original rent increase notice, proof of delivery, and calculations in a permanent file

FAQ: Rent Increase Compliance Under Oregon Law

Q: Can I increase rent by the CPI-U limit plus extra for property tax increases?

A: No. ORS 90.323(2) caps rent increases at the CPI-U percentage, period. You cannot add surcharges, "operating cost" increases, or property tax pass-throughs above the CPI limit. If property taxes or insurance rise faster than the CPI-U, you absorb the difference or attempt an increase in the following year's CPI cycle. Some landlords attempt to circumvent this by converting rent to "rent + utilities + CAM charges." This fails: the rule applies to any payment the tenant makes for occupancy, however labeled.

Q: What if I gave 90 days' notice but the tenant paid for only 60 days before moving out?

A: The 90-day notice requirement applies to when the increase takes effect, not how long the tenant occupies at the new rate. If you gave proper 90-day notice for an increase effective September 1, 2026, and the tenant gives 30-day notice to terminate their lease on August 15, 2026, the tenant doesn't owe the increased rent. The increase never took effect for that tenant because they left before the effective date. You cannot backdate or accelerate an increase; the effective date is fixed by the notice you deliver.

Q: Can I include the CPI-U increase in a lease renewal rather than sending a separate rent increase notice?

A: A new lease that reflects the CPI-U-adjusted rent is permissible if the tenant signs it before the increase takes effect. However, the statute requires written notice of the increase, not just a new lease. Best practice: send a separate rent increase notice 90 days before the effective date. If the tenant signs a new lease at the increased amount, retain both the notice and the signed lease as proof of compliance.

Q: What if the CPI-U data is delayed or corrected?

A: The BLS publishes the August 31 CPI-U figure in the first week of September each year. If there's a delay, use the most recent published figure available. If the BLS later corrects a figure, you're bound by the corrected figure going forward, but prior notices sent using the earlier data are generally considered compliant (absent fraud or gross negligence). Don't second-guess your calculation mid-year; rely on published data as of the date you send notice.

Q: Do I need to notify tenants of the CPI-U limit, or can I just state the increase amount?

A: The statute requires only that you provide written notice of the increase and the effective date. You're not required to disclose the CPI-U percentage or calculation method. However, transparency is wise: including "This increase is 2.6%, the maximum allowed under ORS 90.323(2) based on the current CPI-U index" on your notice demonstrates good faith and reduces the likelihood of disputes.

Q: If a tenant refuses to pay the increased rent, what are my options?

A: If the increase is legal and you've given proper notice, you can serve a 3-day pay-or-quit notice (ORS 90.405) and file for eviction if the tenant doesn't comply within 3 days. However, the tenant can defend the eviction by claiming the increase was illegal. If they prove it was illegal (e.g., exceeded the CPI-U limit or lacked proper notice), the eviction fails and you owe them damages. Never evict for non-payment of an increase you're unsure about; verify compliance first.

Where to Find Current CPI-U Data and Guidance

U.S. Bureau of Labor Statistics: bls.gov/cpi — Select "Portland-Seattle-Tacoma" metropolitan area, search for "CPI for All Urban Consumers (CPI-U)," and look for the most recent 12-month change percentage.

Oregon Attorney General Consumer Complaint Division: doj.oregon.gov — Publishes annual rent increase limits and landlord-tenant compliance guidance.

Community Alliance of Tenants (CAT): oregontenants.org — Provides tenant resources but also publishes rent increase limits for landlord reference.

Oregon State Bar Lawyer Referral Service: osbar.org — For landlords needing legal review of rent increase notices before delivery.

Key Compliance Reminders for Fall 2026 and Beyond

As we enter late 2026, keep these points in mind:

For increases effective in 2027: The new CPI-U figure (for the 12-month period ending August 31, 2026) will be published in early October 2026. If you plan rent increases for November or December 2026, you must use the 2.6% limit (current through August 31, 2026). You cannot apply the new CPI-U figure until September 1, 2027, rent increases take effect.

Audit your 2025 increases: If you increased rent in 2025, review those notices and calculations now. If you miscalculated or failed to provide 90-day notice, a tenant may still have a claim (Oregon's statute of limitations for rent overcharges is typically 3 years). Proactively review past years to identify and correct any errors.

Multifamily buildings: If you own a multifamily building, you can increase rents on a unit-by-unit basis as leases renew, or on a property-wide basis with individual 90-day notices. Stagger increases or apply them uniformly—either way is compliant, as long as you give 90 days' written notice to each tenant before their increase takes effect.

Staying Compliant: The Self-Managing Landlord's Advantage

Self-managing a 2–75 unit portfolio requires discipline, but rent increase compliance is one area where small landlords can maintain an edge. Unlike large institutional landlords that might have in-house legal review, you can personally verify every calculation, track every notice, and maintain complete records.

The risk comes from shortcuts: relying on memory instead of written calculations, trusting verbal notice instead of certified mail, or using last year's CPI-U when the new figure is available. Each shortcut multiplies compliance risk.

Oregon courts and the Attorney General expect landlords to know the law. Ignorance of the CPI-U limit or notice requirements is not a defense. Document everything, verify calculations twice, and deliver notices using methods you can prove. These simple disciplines eliminate 90% of rent increase disputes.

LeaseBase tracks lease renewal dates, rent amounts, and compliance deadlines across your portfolio, reducing the administrative burden and catching issues before you send notice to tenants. For larger portfolios where manual tracking becomes error-prone, this automation is an efficient alternative to hiring a part-time bookkeeper or paying a property manager 8–12% of rent collected.

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Disclaimer: This article is for informational purposes only and does not constitute legal advice. Consult a qualified attorney for guidance specific to your situation. Oregon landlord-tenant law is subject to regular interpretation by courts and regulatory agencies. Verify current rules with the Oregon Attorney General or a licensed Oregon landlord-tenant attorney before implementing any rent increase.