LOMA vs. LOMR: What's the Difference? A Guide to FEMA Map Changes

If a property has been mapped into a Special Flood Hazard Area (SFHA) by FEMA, it doesn't necessarily mean the property will stay there forever. FEMA provides formal processes to challenge or change flood zone designations when the data supports it.

The two most common mechanisms are the Letter of Map Amendment (LOMA) and the Letter of Map Revision (LOMR). While they sound similar, they serve very different purposes, apply to different situations, and follow different processes.

This guide explains both, helps you determine which one applies to your situation, and walks you through the steps involved.

The Quick Comparison

What Is a LOMA (Letter of Map Amendment)?

A Letter of Map Amendment is FEMA's official determination that a specific property or structure has been incorrectly included in a Special Flood Hazard Area. The LOMA establishes that the property is naturally at or above the Base Flood Elevation (BFE) and therefore should not be subject to SFHA requirements.

Key Characteristics

• Based on natural ground conditions — the property must be on naturally high ground, not elevated by fill
• Applies to individual properties or structures (not entire neighborhoods)
• Does not actually change the FEMA flood map — it creates a property-specific exception
• Once issued, the mandatory flood insurance requirement is removed for that property

When a LOMA Applies

A LOMA is appropriate when:

1. A property is shown as being in an SFHA on the current FEMA map
2. The property's natural ground elevation is at or above the BFE
3. The property has NOT been elevated using fill material
4. The property owner wants to remove the mandatory flood insurance requirement

Common LOMA Scenarios

• Mapping precision issues: FEMA maps are created at a broad scale. Individual properties near the edges of flood zone boundaries may be incorrectly included due to limited map resolution.
• Terrain variations: A property on a slight rise or ridge may be naturally above BFE even though the surrounding area floods.
• Updated elevation data: Newer, more accurate elevation data (LiDAR surveys) may show that a property was mapped incorrectly based on older topographic information.

How to Apply for a LOMA

Step 1: Get an Elevation Certificate

Hire a licensed surveyor or professional engineer to prepare an Elevation Certificate (FEMA Form 086-0-33). This document establishes the property's elevation relative to the BFE.

Cost: Typically $300-600 depending on your area.

Step 2: Complete the MT-1 Application

FEMA's application for a LOMA is the MT-1 form (available through FEMA's online portal at https://hazards.fema.gov/femaportal/onlinelomc).

Required documentation:
- Completed application form
- Elevation Certificate
- Copy of the property deed
- Tax assessor's map or plat showing the property
- Community acknowledgment (required for some applications)

Step 3: Submit and Wait

For single residential lot or structure applications, there is no FEMA review fee. Processing typically takes 4-8 weeks, though it can be faster or slower depending on FEMA's workload.

Step 4: Receive Your LOMA

If approved, FEMA issues a Letter of Map Amendment officially determining that your property is not in the SFHA. You can then:
- Contact your lender to remove the mandatory flood insurance requirement
- If you want to keep flood insurance (recommended), you may qualify for significantly lower premiums
- Provide the LOMA to future buyers as documentation

LOMA Success Rate

LOMAs have a relatively high approval rate when the elevation data supports the application. The most common reason for denial is that the property's lowest adjacent grade or lowest floor elevation is actually below the BFE.

What Is a LOMR (Letter of Map Revision)?

A Letter of Map Revision is FEMA's official modification to an effective Flood Insurance Rate Map. Unlike a LOMA, a LOMR actually changes the official map to reflect altered flood conditions in an area.

Key Characteristics

• Based on physical changes that have altered the flood hazard in an area
• Requires detailed engineering analysis (hydrologic and hydraulic studies)
• Actually revises the FEMA map — not just a property-specific exception
• Can add or remove areas from the SFHA
• More complex, expensive, and time-consuming than a LOMA

When a LOMR Applies

A LOMR is appropriate when:

1. Physical changes have been made that alter flood hazard conditions (e.g., levee construction, channel improvements, bridge modifications, fill placement)
2. Better technical data shows the existing map is inaccurate
3. The changes affect an area larger than a single property
4. The applicant wants the official FEMA map to be revised

Common LOMR Scenarios

• New levee or floodwall construction: A community builds a levee that protects an area previously in the floodplain
• Channel improvements: A river or creek channel is widened, deepened, or realigned, reducing upstream flood levels
• Bridge or culvert modifications: Changes to bridge or culvert capacity that affect water surface elevations
• Large-scale development: Significant grading or fill placement that changes drainage patterns
• Updated engineering studies: New hydrologic/hydraulic modeling that produces different results than the original study

Types of LOMRs

Standard LOMR

A revision based on physical changes already completed (as-built conditions). This is the most common type.

Conditional LOMR (CLOMR)

A Conditional Letter of Map Revision is FEMA's comment on whether a proposed project, if built as designed, would meet the criteria for a map revision. It's essentially a pre-approval.

Important: A CLOMR does not change the map. It provides assurance that a LOMR will be issued once the project is completed and as-built documentation is submitted.

CLOMRs are particularly useful for:
- Developers who need to know before investing in construction
- Communities planning infrastructure improvements
- Projects requiring financing that depends on flood zone status

LOMR-F (Letter of Map Revision Based on Fill)

A LOMR-F is a specific type of LOMR for properties that have been elevated using engineered fill to or above the BFE. It functions similarly to a LOMA but applies when the elevation is artificial rather than natural.

Requirements:
- Elevation Certificate showing the property is at or above BFE
- Certification that fill was properly placed and compacted
- Community acknowledgment
- FEMA review fee applies

How to Apply for a LOMR

Step 1: Engage a Licensed Professional Engineer

LOMR applications require detailed engineering studies that must be prepared and certified by a licensed professional engineer (P.E.). This is not a DIY process.

Step 2: Prepare the Technical Submission

Required documentation typically includes:
- Completed MT-2 application forms
- Hydrologic and hydraulic analyses
- Topographic mapping and survey data
- Floodway data tables
- Certified as-built drawings (for completed projects)
- Community acknowledgment and concurrence
- Environmental and regulatory compliance documentation

Step 3: Pay Review Fees

FEMA charges review fees for LOMR applications:
- LOMR: Starting at $6,750 (fees vary based on complexity)
- CLOMR: Starting at $6,750
- LOMR-F: Starting at $525 for single residential lots

Step 4: FEMA Review

FEMA reviews the engineering analysis, may request additional information or revisions, and ultimately issues a determination. This process typically takes 6-12 months and can take longer for complex projects.

Step 5: Map Revision

If approved, FEMA issues a Letter of Map Revision that officially changes the flood map. This may be incorporated into the next physical map revision cycle or issued as a standalone amendment.

LOMA vs. LOMR: Which Do You Need?

Choose LOMA if:

• ✅ Your property is on naturally high ground above BFE
• ✅ You're an individual property owner
• ✅ No physical changes have been made to the property or surrounding area
• ✅ You want a quick, low-cost resolution
• ✅ You just need the mandatory insurance requirement removed for your specific property

Choose LOMR if:

• ✅ Physical changes have been made (fill, levees, channels, etc.)
• ✅ The change affects a larger area, not just one property
• ✅ You want the official FEMA map to be revised
• ✅ You're a developer, community, or entity willing to invest in engineering studies

Choose LOMR-F if:

• ✅ Your property has been elevated using engineered fill to or above BFE
• ✅ You need documentation that the property is no longer in the SFHA
• ✅ The fill has been properly placed and certified

What Happens After You Receive a LOMA or LOMR?

Flood Insurance Implications

• LOMA: You can request that your lender remove the mandatory flood insurance requirement. If you cancel your policy within the first year after the LOMA, you may be entitled to a premium refund.
• LOMR: Properties removed from the SFHA by a LOMR are no longer subject to mandatory purchase requirements. However, map changes can go both ways — a LOMR can also add properties to the SFHA.

Should You Keep Flood Insurance?

Even after a successful LOMA or LOMR, FEMA and most flood experts recommend maintaining flood insurance. The property's elevation relative to flood levels may provide comfort, but:

• Flood maps are based on models, not guarantees
• Extreme events can exceed the 1% annual chance flood
• Flood insurance is typically very affordable for properties outside the SFHA
• Climate and development patterns are changing flood risk over time

Impact on Property Value

A LOMA or LOMR that removes a property from an SFHA can have a positive impact on property value by:
- Eliminating mandatory insurance costs ($700-3,000+/year savings)
- Removing a potential barrier for buyers
- Improving marketability

Common Mistakes and Tips

Mistake 1: Applying for a LOMA When Fill Was Used

If the property was elevated using fill, a LOMA will be denied. You need a LOMR-F instead. Check with your surveyor about the nature of the elevation.

Mistake 2: Not Getting an Elevation Certificate First

Before investing time in any application, get an Elevation Certificate. If the property's elevation is below BFE, neither a LOMA nor LOMR-F will be successful (without additional work).

Mistake 3: Assuming the Process Is Quick

While LOMAs are relatively fast (4-8 weeks), LOMRs can take 6-12+ months. Plan accordingly, especially if the timeline affects a real estate transaction.

Mistake 4: Ignoring the Community

Both LOMA and LOMR processes typically require community acknowledgment — the local floodplain administrator must sign off. Engage them early.

Mistake 5: Not Recording the LOMA/LOMR

Ensure the LOMA or LOMR is properly recorded and associated with the property. Future buyers and lenders need access to this documentation. Provide copies to your lender, insurance agent, and local floodplain manager.

Start with a Flood Determination from FloodCert.org

Before pursuing a LOMA or LOMR, you need to know your current flood zone designation. FloodCert.org provides instant, certified flood determinations so you can see exactly where your property stands — and decide whether a map change is worth pursuing.

Get your flood determination at FloodCert.org →