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Map Amendments · Deep Reference Guide

LOMAs & LOMRs Explained

What a Letter of Map Amendment is, who qualifies by foundation type, how the eLOMA process works, the real cost-and-savings math, what happens when FEMA says no — and how to protect a LOMA when the next map revision comes.

What is a LOMA?

A Letter of Map Amendment (LOMA) is an official FEMA letter that amends the Flood Insurance Rate Map to remove a specific property — a structure, a parcel, or both — from the Special Flood Hazard Area. It is not a change to the FIRM itself; it is an administrative amendment that creates a formal record that the property has been determined to be above the mapped flood hazard.

When FEMA grants a LOMA, the property is officially out of the SFHA for insurance and regulatory purposes. For homeowners with federally backed mortgages, this eliminates the mandatory flood insurance requirement — the lender must remove the insurance condition once the LOMA is provided. The property remains physically in the same location; what changes is its official regulatory classification.

LOMAs exist because flood maps are drawn at a community scale using topographic data that cannot perfectly represent every individual structure. A property can fall within the shaded SFHA boundary on a FIRM even when its actual ground elevation is above the Base Flood Elevation — because the map's resolution or data vintage didn't capture that distinction. A LOMA corrects the classification for that property without requiring a full map revision.

The key insight: Being in the SFHA on the map and actually being at flood risk are not the same thing. The SFHA boundary is a modeled estimate drawn from engineering analysis and topographic data — sometimes decades old. A LOMA is the mechanism that resolves the discrepancy when your property's actual elevation is more favorable than the map assumed.

LOMA vs. LOMR vs. LOMR-F — knowing which applies

These three mechanisms are frequently confused. They serve different purposes and have different requirements.

LOMA — Letter of Map Amendment

Property-level administrative amendment. No physical changes to the property are involved. Based entirely on a surveyed determination that the property's natural ground elevation or lowest floor elevation is at or above the BFE. Applies to a single structure or parcel. The most common mechanism for individual homeowners. Does not change the printed FIRM — creates an administrative overlay.

LOMR — Letter of Map Revision

Revises the FIRM itself — changing zone boundaries, BFEs, or floodway designations. Typically filed by communities, developers, or engineers in response to physical changes (a new levee, channel improvement, detention basin) or to correct engineering errors affecting a broader area. A LOMR changes what appears on the actual FIRM panel, not just an administrative record. More complex, more expensive, longer timeline. Affects multiple properties or an entire reach.

LOMR-F — Letter of Map Revision Based on Fill

A hybrid mechanism for properties that were elevated by placing fill material. Like a LOMA, it applies to a single site — but unlike a LOMA, it requires documentation that fill was placed lawfully before the structure was built or before the current FIRM effective date. Requires an engineering certification that the fill meets hydraulic standards — specifically, that it doesn't displace floodwater in a way that increases flood levels on adjacent properties. More rigorous review than a standard LOMA; FEMA scrutinizes fill certifications carefully.

Which one for you? If your property has always been at its current elevation and no fill has been placed — a LOMA is the right mechanism. If fill was placed before construction specifically to elevate the site — a LOMR-F applies. If you need to change the FIRM for your entire neighborhood or street — a LOMR filed by or through the community is the path.

Eligibility — what FEMA is actually looking for

LOMA eligibility comes down to a single core question: Is the relevant elevation at or above the Base Flood Elevation? But "relevant elevation" depends on what type of LOMA is being sought.

FEMA evaluates two different elevation points depending on what the applicant is trying to remove from the SFHA:

  • Lot-based LOMA: The lowest natural ground elevation of the entire parcel must be at or above the BFE. This is a stricter standard — it means even the lowest corner of the property is above BFE. Required when the goal is to remove the entire lot, not just the structure.
  • Structure-based LOMA: The lowest adjacent grade — the ground immediately next to the building — must be at or above the BFE. This is a more achievable standard. A property can have low areas away from the structure while the building pad itself is above BFE. This is the most common LOMA type for residential properties.

Beyond the elevation question, FEMA also confirms that:

  • The property is actually shown within the SFHA on the current effective FIRM
  • A BFE has been established for the area (Zone AE, VE, AH — not Zone A without BFE)
  • The elevation data submitted is prepared by a licensed engineer, surveyor, or architect
  • The application is complete and consistent — property location, FIRM panel, and elevation data are internally coherent

One eligibility factor that surprises many applicants: FEMA reviews the natural ground elevation, not the elevation of any fill placed after the FIRM effective date. Fill placed after the current FIRM went into effect does not count toward LOMA eligibility — it may support a LOMR-F if placed before the structure was built, but standard LOMAs use natural or pre-FIRM ground elevations.

Eligibility by foundation type — what each means for your situation

Foundation type is one of the most important variables in LOMA eligibility. Different foundation types expose different floors to flood risk and are evaluated differently by FEMA.

Slab-on-grade

Most favorable for LOMA

The finished floor sits directly on the concrete slab. The slab elevation is the lowest floor elevation. If the slab is at or above BFE, the structure-based LOMA standard is typically met. Survey documents the top of slab elevation and the lowest adjacent grade. Generally the most straightforward LOMA application type.

Crawlspace

Depends on vent configuration

If the crawlspace has flood openings (vents that allow water to flow through), FEMA evaluates the lowest adjacent grade, not the crawlspace floor. If it's an unvented, enclosed crawlspace, FEMA may treat it as a basement. Whether and how the crawlspace is flood-vented substantially affects what elevation FEMA uses as the reference point.

Basement

Most challenging — floor is the reference

For structures with basements, FEMA uses the basement floor elevation as the lowest floor — not the first floor above grade. A structure with a finished first floor 2 feet above BFE but a basement 4 feet below BFE does not qualify for a structure-based LOMA. The basement makes the entire structure below BFE by definition. Lot-based LOMA may still be possible if the entire parcel is above BFE.

Elevated / Pier & Beam

Lowest adjacent grade is key

For elevated structures on piers, columns, or piling foundations, FEMA evaluates the lowest adjacent grade and the nature of the enclosure below the elevated floor. Open foundations with no enclosure: lowest adjacent grade is the reference. Enclosed areas below the elevated floor may be evaluated as basement or enclosure depending on configuration.

The practical implication: before committing to a LOMA application, understanding your foundation type and how FEMA will classify it determines whether you use the lot-based or structure-based standard — and whether a LOMA is viable at all. This is one of the most important assessments in a Comprehensive Review.

Who files the application

Property owners and lessees can initiate LOMA requests. However, the Elevation Certificate and any engineering certifications required must be prepared by a licensed land surveyor, civil engineer, or registered architect authorized under state law to certify elevation information. The property owner cannot self-certify elevation data — the professional seal is what gives the EC its standing with FEMA.

In practice, most LOMA applications are prepared by or with a licensed land surveyor who surveys the property, prepares the EC, and often submits the application to FEMA on the owner's behalf. Some civil engineers offer the same service. When shopping for a surveyor, ask specifically whether they handle LOMA applications — not all do, and those that do are typically faster and more cost-effective because they've done it before.

Attorneys and consultants sometimes assist with the process, particularly for complex cases or appeals, but the technical work — elevation survey and EC preparation — must be done by a licensed design professional.

The eLOMA portal — how it works

FEMA's eLOMA system allows licensed surveyors and engineers to submit LOMA applications electronically for qualifying simple cases. When it works, it's fast — determinations can come back in 1 to 5 business days, compared to 60+ days for traditional paper submissions.

eLOMA is available for:

  • Single-structure residential properties
  • Properties in Zone AE or AH with a published BFE
  • Applications where the structure's lowest floor or lowest adjacent grade is clearly above BFE
  • Submissions by FEMA-registered licensed professionals

eLOMA is not available for coastal V zones, Zone A without BFE, complex multi-structure properties, or cases involving fill or other complications. Those go through the traditional MT-1 process.

The licensed professional — not the property owner — submits through the portal. The owner provides the property information and access for the survey; the surveyor or engineer handles the portal submission. If you're working with a surveyor, ask upfront whether your case qualifies for eLOMA and whether they use the portal — it can shave weeks off your timeline.

The full MT-1 process — step by step

1

Preliminary eligibility assessment

Before spending money on a survey, assess whether LOMA eligibility appears viable from available data. Topographic data, community floodplain records, and the BFE for the property from the FIS can provide a preliminary indication of whether the property's ground elevation is likely above BFE. This is what a Comprehensive Review's LOMA pathway assessment does — using public data to evaluate likelihood before you commit to survey costs.

2

Hire a licensed land surveyor

Engage a licensed land surveyor experienced with LOMA applications in your jurisdiction. Provide them with your property address, FIRM panel number, and BFE from your zone (or let them obtain it). The surveyor will visit the property, establish the relevant elevations using professional survey equipment, and prepare the Elevation Certificate on FEMA Form 086-0-33.

When getting quotes, clarify whether the price includes EC preparation only or EC preparation plus LOMA application filing. Many surveyors bundle both. Costs vary significantly by market — $500 to $1,500 for the EC, with some charging separately for LOMA submission.

3

Confirm the datum

This step is frequently overlooked and causes application errors. The BFE on your FIRM is expressed in either NAVD 88 (North American Vertical Datum of 1988) or the older NGVD 29 (National Geodetic Vertical Datum of 1929). The two differ by fractions of a foot to over a foot depending on location. Your surveyor must survey in the same datum as your FIRM's BFE — or convert correctly. A surveyed elevation in NAVD 88 compared to a BFE in NGVD 29 without conversion produces an incorrect eligibility conclusion. Confirm with your surveyor that they've verified the FIRM datum before the survey.

4

Prepare and submit the MT-1 application

The MT-1 package consists of the completed FEMA MT-1 form, the signed and sealed Elevation Certificate, a copy of the FIRM panel with the property location marked, and a recorded plat or tax map showing property boundaries. For eLOMA-qualifying cases, the surveyor submits electronically. For paper submissions, the package goes to FEMA's Map Service Center. FEMA charges no application fee — the costs are the surveyor's fees and any engineering review costs for complex cases.

5

FEMA review

FEMA reviews the application for completeness and technical accuracy. For eLOMA cases, review is largely automated for straightforward applications — determinations within days. For MT-1 paper submissions, FEMA's published target is 60 days, though actual processing times vary. If FEMA needs additional information, they issue a request — responding promptly keeps the timeline on track. If the application is deficient, FEMA may issue a denial rather than a request for information, in which case a new application would be required.

6

LOMA issued — notify your lender and insurer

Once FEMA issues the LOMA, provide a copy to your mortgage lender. The lender is legally required to remove the mandatory flood insurance requirement. Provide a copy to your flood insurance carrier as well — you may cancel your policy and receive a pro-rated refund for the unused premium period. The LOMA is recorded with FEMA and is searchable in their records — future buyers of your property can verify it.

The cost and savings math — what the numbers actually look like

LOMA economics vary by property but the general framework is consistent. Here are three representative scenarios:

Scenario A — Zone AE, slab foundation, premium $2,800/year
Surveyor / EC + LOMA filing$850
FEMA application fee$0
Total upfront cost$850
Annual premium eliminated$2,800
Payback period~4 months
10-year net savings (post-cost)$27,150
Scenario B — Zone AE, crawlspace, premium $4,200/year with RR2.0 increases
Surveyor / EC + LOMA filing$1,200
FEMA application fee$0
Total upfront cost$1,200
Annual premium eliminated$4,200 (and rising)
Payback period~3.5 months
10-year net savings (conservative, no RR2.0 growth)$40,800
Scenario C — Ineligible (basement below BFE) — LOMA denied
Surveyor / EC cost$900
LOMA outcomeDenied — basement below BFE
EC still useful forNFIP rating, private market quotes
Net benefit from EC despite denialPotential $400–800/yr premium reduction

Scenario C illustrates why preliminary assessment matters — knowing your foundation type and approximate elevation before commissioning a survey prevents spending $900 to confirm ineligibility. The EC still has value for insurance rating purposes even when a LOMA isn't viable, but that's a different calculation than LOMA economics.

What happens after a LOMA is granted

The LOMA removes the mandatory purchase requirement. Your lender acknowledges it and cancels the insurance mandate. You may cancel your flood insurance and receive a pro-rated premium refund — typically processed within 30 days of cancellation request.

Important considerations after receiving a LOMA:

  • Flood risk doesn't disappear. A LOMA removes a regulatory classification — not a physical flood hazard. Properties that were marginally above BFE can still flood in extreme events. Many homeowners choose to maintain voluntary flood insurance at the much lower Zone X Preferred Risk Policy rates after a LOMA — usually $400–$700/year vs. $2,000–$5,000 in Zone AE.
  • Keep your LOMA documentation. Store a copy with your property records. Provide a copy to your title company if you refinance or sell — it should be in the property's public record but having a copy ensures it doesn't get overlooked.
  • Inform future buyers. A LOMA adds value to your property by removing a mandatory insurance cost. Make sure it appears in your disclosure documentation when you sell.
  • Monitor map revision activity. LOMAs can be superseded by subsequent FIRM revisions — see the next section.

Protecting your LOMA through future map revisions

This is the aspect of LOMA management most owners don't know about until it's too late. When FEMA revises the FIRM for your community — whether through a countywide remap, a LOMR from a neighboring development, or a Flood Map Modernization update — your existing LOMA may be superseded by the new map.

When a new FIRM is issued, any previously granted LOMAs based on the prior FIRM are effectively voided. The new FIRM establishes new BFEs, new zone boundaries, and a new regulatory baseline. If the new BFE is higher than the old one, a property that was above the old BFE may now be below the new one — even if nothing physically changed at the property.

How to protect yourself:

  • Sign up for FEMA map change notifications for your community at the Map Service Center — FEMA will notify you of proposed changes when you have an active amendment on file.
  • When a map revision is proposed, review the new BFEs for your area during the comment period. If your property remains above the new BFE, a new LOMA application can be submitted once the new FIRM becomes effective.
  • During the comment period, if you believe the proposed BFE is technically incorrect for your area, you can submit a scientific and technical appeal — this is a formal process where you or a hired engineer challenges the new BFE with data. This is uncommon but available.
  • If a countywide remap is announced, track it proactively. These take years from initiation to effective date — giving you time to evaluate your property's status under the proposed new map before it becomes final.

When FEMA denies — and what to do

FEMA denies a LOMA when the submitted elevation data doesn't demonstrate that the property meets the eligibility criteria. Common denial reasons:

  • Lowest adjacent grade or basement floor is below BFE
  • Datum mismatch — surveyed elevation compared against wrong BFE datum
  • Incomplete application — missing EC sections, missing FIRM panel, missing plat
  • Property not located where shown — incorrect FIRM panel reference
  • Fill placed after FIRM effective date — ineligible for standard LOMA, may qualify for LOMR-F

After a denial, options include:

  • Appeal the determination — if you believe FEMA's analysis was technically incorrect, a formal appeal can be filed. Appeals must be supported by additional technical data. An engineer reviewing FEMA's denial rationale can advise whether an appeal has merit.
  • Request a Scientific and Technical Appeal — if the denial reflects a disagreement about the BFE methodology or data quality, not just your property's elevation, a technical appeal challenging the BFE itself is possible. These are resource-intensive and typically pursued by engineers or attorneys, not individual homeowners directly.
  • Pursue LOMR through community — if the denial reflects a broader mapping issue affecting your neighborhood, working with the community's floodplain manager to pursue a community-level LOMR may be an option.
  • Re-evaluate private flood insurance — a denial doesn't change your premium situation directly, but the EC generated during the process may still support better NFIP rating or a competitive private market quote.

CLOMR — Conditional Letters of Map Revision

A Conditional Letter of Map Revision (CLOMR) is FEMA's pre-approval for a proposed project that, once completed, would qualify for a LOMR. It's used primarily by developers and communities planning flood control improvements, channel modifications, or significant grading projects that will change the flood hazard profile.

A CLOMR confirms that if the project is completed as designed, FEMA will issue the final LOMR. It provides certainty for financing and permitting — banks, investors, and local authorities often require a CLOMR before approving or funding a major development project in or near a flood zone.

For most individual homeowners, CLOMRs aren't directly relevant — they're part of the development and infrastructure financing landscape. But understanding CLOMRs matters when evaluating a property: if a CLOMR is in process for a neighboring development, it may affect future BFEs and zone boundaries in your area. A CLOMR on file for a project upstream or downstream can be an early warning of zone changes coming.

When a LOMA doesn't apply

  • Zone X properties — already outside the SFHA, no LOMA needed or available
  • Floodway — Floodway designation is based on hydraulic function, not elevation. Properties in the regulatory Floodway cannot be removed via LOMA
  • Structure below BFE — if the lowest floor (including basement) is below BFE, a LOMA is not available without physically elevating the structure first
  • Zone A without BFE — standard LOMA requires an established BFE. In Zone A, a BFE must first be calculated — possible through a FEMA-accepted technical analysis submitted with the application, but more complex
  • V zones without detailed analysis — coastal high-hazard LOMAs involve wave analysis in addition to elevation, requiring more complex engineering
  • Fill placed post-FIRM — fill placed after the FIRM effective date doesn't count toward natural ground elevation for standard LOMA; LOMR-F process applies if fill was pre-structure

Why amendment history research matters before you apply

Searching the public LOMA and LOMR record for a property address before filing a new application matters for several reasons most applicants don't consider:

  • Prior LOMA, now superseded: If a LOMA was previously granted for the property but superseded by a subsequent FIRM revision, the prior EC may still be on file — saving you survey costs if it was recent. The prior determination also provides useful context for a new application.
  • Neighboring LOMR activity: A LOMR filed by a neighboring developer may have changed the BFE in your area without your knowledge. If the new BFE is higher, your property's eligibility changes — and you may not know it without checking the amendment record.
  • LOMR-F on adjacent parcel: Fill placed on an adjacent parcel through a LOMR-F process can affect flood hydraulics in your area — potentially affecting the BFE that applies to your property.
  • Community-level map changes in progress: If a countywide remap or community LOMR is already in FEMA review, filing a LOMA based on the current FIRM creates a LOMA that may be short-lived. Knowing what's in the pipeline is part of a complete LOMA eligibility assessment.
Is Your Property Eligible?

A LOMA could be worth thousands per year — or nothing. The difference is in the data.

Eligibility comes down to your specific elevation vs. your BFE, your foundation type, and your amendment history — none of which a general guide can tell you. A Comprehensive Review assesses all of this from public records before you spend $1,000+ on a survey that may or may not support an application.

Comprehensive includes LOMA pathway assessment, BFE relationship analysis, full amendment history, foundation type context, and referral guidance if viable. 2–3 business day turnaround.

Important: LOMA filing requires a licensed professional engineer or registered land surveyor. This guide is educational and does not constitute engineering advice or a determination of LOMA eligibility. MyFloodReview LOMA pathway assessments evaluate publicly available data — they are not LOMA filings or engineering determinations. Eligibility requires site-specific survey data.
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