San Mateo County Jumbo Loan Limits Explained

Will this home push you into a jumbo loan? If you are shopping in San Mateo, Burlingame, Foster City, or nearby Peninsula neighborhoods, that question comes up fast. Prices often sit close to the line where loans switch from conforming to jumbo, which affects your rate, down payment, reserves, and even appraisal timelines. In this guide, you will learn how loan limits work, how they impact your buying power, and the smart ways to structure a competitive offer in San Mateo County. Let’s dive in.

Conforming vs. jumbo loans: the quick picture

A conforming loan meets Fannie Mae and Freddie Mac guidelines and stays at or below the county’s conforming loan limit. These are widely available and typically come with more competitive rates and fees. You can read more about conforming products in the overviews from Fannie Mae and Freddie Mac.

A jumbo loan is any loan amount above the county’s conforming limit. Jumbos are not sold to Fannie or Freddie, so lenders often apply stricter standards on credit, debt-to-income, reserves, and documentation. The Consumer Financial Protection Bureau’s mortgage basics are a helpful primer if you want a neutral overview.

Here is your quick check while touring homes:

• Start with the price you are targeting.
• Subtract your planned down payment.
• Compare that loan amount to the county’s conforming limit.
• If your loan amount is above the limit, you will need a jumbo or an alternative structure.

How loan limits are set

The Federal Housing Finance Agency sets conforming loan limits each year by county. Some counties, including parts of the Bay Area, qualify for high-cost limits that sit above the national baseline. Limits can change annually based on home price trends. Before you write an offer or lock a rate, confirm the current figure on the FHFA conforming loan limits page.

Why the threshold matters in San Mateo County

On the Peninsula, many homes naturally price near or above the conforming limit. That means a small shift in your target price or down payment can move your loan from conforming to jumbo. In a competitive market like Burlingame, San Mateo, Foster City, Belmont, San Carlos, Millbrae, and Redwood City, understanding where your loan falls helps you plan for rate, cash needs, and how to write a strong, realistic offer.

Neighborhood selection can influence which path fits best. Some areas and property types tend to push buyers into jumbo territory more often, while others may allow a conforming structure with a slightly larger down payment or a second loan.

What changes when you cross into jumbo

Rates and pricing

Conforming loans often have lower base rates and more favorable pricing because lenders can sell them easily. Jumbo rates can be higher or similar depending on market conditions and investor appetite. The key is to compare total cost, not just the headline rate. Consider the rate, lender fees, and any added reserve requirements that affect your cash position at closing.

Down payment and mortgage insurance

Conforming loans may allow smaller down payments with private mortgage insurance. PMI adds to your monthly cost until your loan-to-value ratio drops. Jumbo loans typically require larger down payments and do not use standard PMI programs. Some lenders offer portfolio solutions or a second lien to bridge the gap, but these can raise your effective cost.

Credit, DTI, and reserves

Jumbo underwriting is usually more conservative. Expect higher minimum credit score requirements, lower allowed debt-to-income ratios, more months of liquid reserves, and deeper documentation. You might qualify for a certain amount on paper with a conforming loan but fall short under a specific jumbo lender’s overlays. Get pre-approved early with a lender experienced in Peninsula jumbos.

Appraisals and valuation

Higher-value homes and unique properties can be harder to appraise. Jumbo lenders may require extra appraisal work or more detailed valuation reviews. Limited comparable sales can slow timelines or create negotiation friction if an appraisal comes in low.

Timeline and closing speed

Jumbo files sometimes take longer because lenders review more documentation. Many local lenders can still close quickly, but you should factor in appraisal scheduling and any additional underwriting conditions. When you write a competitive offer, balance speed with sensible protections.

Strategies to stay within limits or manage a jumbo

If you are close to the line, you have options. Each path comes with tradeoffs, so ask your lender to model the total cost and cash impact.

• Increase down payment. Putting more cash down reduces your loan amount and may keep you under the conforming limit.
• Target the right price range. Shop in neighborhoods or focus on properties where your planned down payment results in a conforming loan amount.
• Use a split loan structure. Pair a conforming first mortgage with a second lien or HELOC to cover the difference. This can avoid PMI and keep the first loan conforming, but it adds complexity and may raise your blended interest cost.
• Consider adjustable-rate mortgages. ARMs can lower your initial rate on either conforming or jumbo loans. This is a pricing strategy, not a limit workaround, so weigh your time horizon and rate risk.
• Strengthen liquid reserves. If you need a jumbo, robust reserves can improve approval odds and may open better pricing tiers.
• Explore rare alternatives. Seller carryback financing is occasionally used to bridge a gap, but it requires careful negotiation and legal review.

Offer tactics that work in San Mateo’s fast market

• Present a clean, confident offer. Larger earnest money, concise inspection periods, and clear financing language demonstrate readiness.
• Match your financing contingency to your loan type. If you need a jumbo, include proof of pre-approval and evidence of required reserves.
• Prepare for the appraisal. Have your lender and agent align on timelines and discuss backup options if valuation is tight.
• Use cash strategically. If you can bring enough cash to keep the first mortgage conforming, that can strengthen your offer while controlling long-term cost.

Lender selection and pre-approval

• Work with lenders who do both conforming and jumbo at scale and who know Peninsula appraisals.
• Ask about overlays. Clarify minimum down payment, reserve requirements, credit score floors, and maximum debt-to-income ratios for the exact product you need.
• Discuss rate locks and extensions. Jumbo files can take longer, so make sure your lock strategy fits your closing timeline.
• Request a precise pre-approval letter. Ask the lender to state whether your amount is conforming or jumbo and to list any special conditions.

What to confirm with your lender

• The current FHFA conforming limit for San Mateo County. Verify on the FHFA conforming loan limits page.
• Whether your target price and down payment produce a conforming or jumbo loan amount.
• Lender-specific jumbo requirements for down payment, reserves, credit score, and debt-to-income.
• PMI options and costs for high loan-to-value conforming loans.
• Typical underwriting and appraisal timelines for your lender and product type.
• HOA and condo project eligibility if you are buying a condo in San Mateo, Foster City, or Redwood Shores.
• Appraisal approach for high-value or unique homes. Understand if an additional review or second appraisal might be required.

For plain-language definitions and planning tools, the CFPB’s mortgage basics guide is a helpful resource.

San Mateo County nuances to keep in mind

• Many buyers face the conforming versus jumbo decision across the Peninsula’s mid to upper price ranges.
• Condos can bring added scrutiny on HOA financials and project eligibility, especially at higher price points.
• Custom or unique homes may require extra appraisal work and time.
• Multi-unit properties follow different rules, and occupancy matters, so align early with your lender about how you plan to use the property.

Buyer action checklist for Peninsula tours

• Get pre-approved with a lender that actively funds both conforming and jumbo loans in high-cost counties.
• Ask for two scenarios: a conforming structure and a jumbo structure, each with total monthly cost, reserves, and estimated cash to close.
• Define your walk-away limits on price and timelines before you submit offers.
• Identify neighborhoods where your budget is most likely to keep you conforming if that is your goal.
• If you will go jumbo, gather documentation and assets early to streamline underwriting.
• Coordinate appraisal timing with your lender and agent to support a competitive but realistic closing date.

Local market context and planning

San Mateo County’s market can move quickly, and multiple offers are common in many neighborhoods. The difference between conforming and jumbo can shape your negotiating position as much as your monthly payment. When rates are volatile, a conforming structure might offer noticeable pricing advantages and simpler underwriting. In other seasons, jumbo pricing can be similar, but underwriting and reserves still matter. The bottom line is to compare complete offers side by side and choose the path that best fits your goals, cash flow, and timeline.

If you want data-driven context for current trends, the California Association of Realtors market data portal is a useful statewide resource. For county-level loan limits, always reconfirm the figure with the FHFA’s official tool before you submit an offer.

The bottom line

On the Peninsula, understanding where your loan sits relative to the county limit is essential. It influences your rate, down payment, reserves, appraisal plan, and how you compete for the home you want. With the right lender, a clear comparison of options, and a well-structured offer, you can buy confidently in San Mateo County.

If you would like a calm, strategic approach tailored to your goals, reach out. We will align your financing strategy with neighborhood-specific guidance and a competitive offer plan that fits San Mateo’s pace. Connect with Andrew Klink to schedule your complimentary Peninsula market consultation.

FAQs

Jumbo loans in San Mateo County: how do I know if I need one?

• Subtract your planned down payment from the price; if the loan amount is above the county’s conforming limit, you will need a jumbo or an alternative split-loan structure.

Rates and costs: will a jumbo loan always be more expensive?

• Not always, but jumbos often carry higher rates or fees; shop multiple lenders and include local portfolio lenders and credit unions in your comparisons.

PMI rules: can you avoid mortgage insurance on a conforming loan?

• PMI is usually required when your loan-to-value is high; alternatives include a larger down payment, lender-paid MI options, or a split-loan structure with tradeoffs.

Cash reserves: how much do jumbo lenders want to see?

• Requirements vary, but it is common to see several months of mortgage payments in liquid reserves; exact amounts depend on the lender and your profile.

Appraisals in San Mateo: are there special challenges?

• Yes, high-value and unique properties can have fewer comparable sales; jumbo lenders may require more detailed appraisal reviews, which can add time.

Relocating to the Peninsula: what is the first step?

• Get pre-approved by a lender experienced with high-cost county jumbos and verify the current FHFA conforming limit to set realistic price and down payment targets.