FMVSS 403: Platform Lift Systems for Motor Vehicles explained.

What FMVSS 403 says it is for

The eCFR heads this section "Standard No. 403; Platform lift systems for motor vehicles." Under 49 CFR part 571, the Federal Motor Vehicle Safety Standards are the numbered standards that set safety performance requirements for motor vehicles and equipment. The text below is quoted from 571.403 as current through October 29, 2026.

This standard specifies requirements for platform lifts used to assist persons with limited mobility in entering or leaving a vehicle.

The purpose of this standard is to prevent injuries and fatalities to passengers and bystanders during the operation of platform lifts installed in motor vehicles.

What it applies to

The application section of the standard says:

This standard applies to platform lifts manufactured on and after April 1, 2005, that are designed to carry standing passengers, who may be aided by canes or walkers, as well as persons seated in wheelchairs, scooters, and other mobility aids, into and out of motor vehicles.

Applicability is decided by the text of the standard as written, including any exclusions it lists, and by the date-specific rules in it. This page does not decide whether a particular vehicle or item is covered.

How the standard is organized

The eCFR text of 571.403 has these top-level sections:

• S1: Scope
• S2: Purpose
• S3: Application
• S4: Definitions
• S6: Requirements
• S7: Test conditions and procedures

In all, the text has 114 numbered headings. Use the finder above to search them; for example, a search for "test" lists the headings that mention tests.

Second-level headings at a glance

These are the numbered sub-sections one level below the top, in order (first 27 of 27):

• S6.1 Threshold warning signal
• S6.2 Platform lift operational requirements
• S6.3 Environmental resistance
• S6.4 Platform requirements
• S6.5 Structural integrity
• S6.6 Platform free fall limits
• S6.7 Control panel switches
• S6.8 Jacking prevention
• S6.9 Backup operation
• S6.10 Interlocks
• S6.11 Operations counter
• S6.12 Vehicle owner's manual insert
• S6.13 Installation instructions
• S7.1 Test devices
• S7.2 Slip resistance test
• S7.3 Environmental resistance test
• S7.4 Threshold warning signal test
• S7.5 Outer barrier non-deployment interlock and occupied outer barrier interlock test
• S7.6 Inner roll stop non-deployment interlock and occupied inner roll stop interlock test
• S7.7 Wheelchair retention device impact test and edge guard test
• S7.8 Inner roll stop test
• S7.9 Static load test I—working load
• S7.10 Fatigue endurance test
• S7.11 Static load test II—proof load
• S7.12 Handrail test
• S7.13 Wheelchair retention device overload test
• S7.14 Static load test III—ultimate load

Key requirements, quoted from the text

These are excerpts from the requirements sections of 571.403, in the order the standard presents them. Long paragraphs are shortened where marked with [...]; the eCFR has the complete text, tables and figures, which this page omits.

S6 Requirements. (a) Each platform lift must comply with the requirements for private use lifts or public use lifts and with the requirements for all lifts. (b) Each public use lift must (1) Comply with the requirements for public use lifts and with the requirements for all lifts. (2) Bear a label with the words “DOT—Public Use Lift” as certification of compliance with the requirements specified in paragraph S6(b)(1). (c) Each private use lift must (1) Comply with the requirements for private use lifts and with the requirements for all lifts. (2) Bear a label with the words “DOT—Private Use Lift” as certification of compliance with the requirements specified in S6(c)(1). (d) Platform lifts suitable for installation on buses, school buses, and MPVs other than motor homes with a GVWR greater than 4,536 kg (10,000 lb.), except motor homes, must be certified by the manufacturer as meeting the requirements for public use lifts. [...]

S6.1 Threshold warning signal. S6.1.1 Except when the platform lift is operated manually in backup mode as required by S6.9, the lift must meet the requirements of S6.1.2 and S6.1.3. The lift is tested in accordance with S7.4 to determine compliance with this section. S6.1.2. Private-use lifts: Except for platform lifts where platform loading takes place wholly over the vehicle floor, a visual or audible warning must activate if the platform is more than 25 mm (1 inch) below the platform threshold area and portions of a passenger's body or mobility aid is on the platform threshold area defined in S4 when tested in accordance with S7.4. [...]

S6.1.5 The audible warning required by S6.1.2 and S6.1.3 must be a minimum of 85 dBA between 500 and 3000 Hz. S6.1.6 The intensity of the audible warning and visibility of the visual warning required by S6.1.2 and S6.1.3 is measured/observed at a location 914 mm (3 ft) above the center of the platform threshold area. (See Figure 2).

S6.2.1 General. Throughout the range of passenger operation and during the lift operations specified in S7.9.3 through S7.9.8, the platform lift must meet the requirements of S6.2.2 through S6.2.4. These requirements must be satisfied both with and without a standard load on the lift platform, except for S6.2.2.2, which must be satisfied without any load.

S6.2.2 Maximum platform velocity. S6.2.2.1 Throughout the range of passenger operation specified in S7.9.4 through S7.9.7, both the vertical and horizontal velocity of the platform must be less than or equal to 152 mm (6 inches) per second when measured at the geometric center of the platform when the platform is unloaded and at the geometric center of the top, horizontal surface of the standard load specified in S7.1.1 when the platform is loaded. S6.2.2.2 Except for platform lifts that manually stow (fold) and deploy (unfold), during the stow and deploy operations specified in S7.9.3 through S7.9.8, both the vertical and horizontal velocity of any portion of the platform must be less than or equal to 305 mm (12 inches) per second.

S6.2.3 Maximum platform acceleration. Throughout the range of passenger operation specified in S7.9.4 through S7.9.7, both the horizontal and vertical acceleration of the platform must be less than or equal to 0.3 g after the accelerometer output is filtered with a channel frequency class (CFC) 3 filter. The filter must meet the requirements of SAE Recommended Practice J211/1 MAR95 (incorporated by reference, see § 571.5), with FH = 3 Hz and FN = 5 Hz. The accelerometer is located at the geometric center of the platform and is mounted directly on the platform when it is unloaded and on the geometric center of the top, horizontal surface of the standard load specified in S7.1.1 when the platform is loaded.

S7 Test conditions and procedures. Each platform lift must be capable of meeting all of the tests specified in this standard, both separately, and in the sequence specified in this section. The tests specified in S7.4, S7.7.4 and S7.8 through S7.12 are performed on a single lift and vehicle combination. The tests specified in S7.2, S7.3, S7.5, S7.6, S7.7.1, S7.13, and S7.14 may be performed with the lift installed on a test jig rather than on a vehicle. Tests of requirements in S6.1 through S6.11 may be performed on a single lift and vehicle combination, except for the requirements of S6.5.3. Attachment hardware may be replaced if damaged by removal and reinstallation of the lift between a test jig and vehicle.

S7.1.1 Test pallet and load. The surface of the test pallet that rests on the platform used for the tests specified in S7.9 through S7.11 and S7.14 has sides that measure between 660 mm (26 in) and 686 mm (27 in). For the tests specified in S7.9 and S7.10, the test pallet is made of a rectangular steel plate of uniform thickness and the load that rests on the test pallet is made of rectangular steel plate(s) of uniform thickness and sides that measure between 533 mm (21 in) and 686 mm (27 in). The standard test load that rests on the pallet is defined in S4.

S7.1.2 Wheelchair test device. The test device is an unloaded power wheelchair whose size is appropriate for a 95th percentile male and that has the dimensions, configuration and components described in S7.1.2.1 through S7.1.2.11. If the dimension in S7.1.2.9 is measured for a particular wheelchair by determining its tipping angle, the batteries are prevented from moving from their original position. S7.1.2.1 a cross-braced steel frame; S7.1.2.2 a sling seat integrated in the frame; S7.1.2.3 a belt drive; S7.1.2.4 detachable footrests, with the lowest point of the footrest adjustable in a range not less than 25 mm (1 in) to 123 mm (5 in) from the ground; [...]

S7.1.2.10 a mass of not less than 72.5 kg (160 lb) and not more than 86.0 kg (190 lb). S7.1.2.11 Batteries with a charge not less than 75 percent of their rated nominal capacity (for tests that require use of the wheelchair's propulsion system).

S7.1.3 Clearance test block for gaps, transitions, and openings. The clearance test block is made of a rigid material and is 16 × 16 × 100 mm (0.625 × 0.625 × 4.0 in) with all corners having a 1.6 mm (0.0625 inch) radius.

S7.1.4 Test Device for detecting platform occupancy. Occupancy of the platform is detected using a 152 × 152 × 305 mm (6 × 6 × 12 inches) rigid box having a total weight of 22.7 kg (50 lb).

Defined terms

The standard defines 23 terms in its definitions section; the first 12 are quoted here from the eCFR.

• Bridging device means that portion of a platform lift that provides a transitional surface between the platform surface and the surface of the vehicle floor within the platform threshold area.
• Cycle means deploying a platform lift from a stowed position, lowering the lift to the ground level loading position, raising the lift to the vehicle floor loading position, and stowing the lift. The term includes operation of any wheelchair retention device, bridging device, and inner roll stop.
• Deploy means with respect to a platform, its movement from a stowed position to an extended position or, one of the two loading positions. With respect to a wheelchair retention device or inner roll stop, the term means the movement of the device or stop to a fully functional position intended to prevent a passenger from disembarking the platform or being pinched between the platform and vehicle.
• Floor reference plane means the plane perpendicular to the longitudinal vehicle reference plane for platform lifts that deploy from the side of the vehicle or perpendicular to the transverse vehicle reference plane for platform lifts that deploy from the rear of the vehicle, and tangent to the outermost edge of the vehicle floor surface adjacent to the lift platform. (See figure 1.)
• Gap means a discontinuity in a plane surface, or between two adjacent surfaces.
• Inner roll-stop means a device that is located at the edge of the platform that a passenger or mobility aid must traverse when entering and exiting the platform from the vehicle floor loading position and that is designed to retain mobility aids on the platform surface during the range of passenger operation.
• Lift reference plane means the plane that is defined by two orthogonal axes passing through the geometric center of the platform surface of a platform lift. One axis is perpendicular to the platform reference plane and the other is parallel to the direction of wheelchair travel during loading of the lift. (See figure 1.)
• Loading position means, with respect to a platform lift, a position at which a passenger can either embark or disembark the lift. The two loading positions are at vehicle floor and ground level.
• Longitudinal vehicle reference plane means the plane that is perpendicular to the floor reference plane and contains the longitudinal axis of the vehicle when the vehicle body is level and moves along with the vehicle body in response to the loading of the vehicle suspension. (See figure 1.)
• Outer barrier is a particular wheelchair retention device that is located on the edge of the platform, is traversed during ground level loading and unloading, and is designed to retain wheelchairs on the platform surface during the range of passenger operation.
• Platform means that portion of a platform lift on which the mobility aid or passenger rests while being raised or lowered.
• Platform lift means a level change device, including any integration of existing vehicle components, and excluding a ramp, used to assist persons with limited mobility in entering or leaving a vehicle.

Limits of this page

This page quotes the text of 49 CFR 571.403 as published in the eCFR, current through October 29, 2026. It omits tables, figures, cross-referenced test procedures in other parts, and the preambles and rulemaking history that explain the rule. It does not tell you whether a given vehicle, part or product complies, how to run a test, or what a manufacturer must certify. Compliance questions go to the manufacturer's engineers, qualified counsel or NHTSA. The eCFR is an editorial compilation, not the official legal edition of the Federal Register.

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 571.403, Standard No. 403; Platform lift systems for motor vehicles. (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR part 571, Federal Motor Vehicle Safety Standards (current through October 29, 2026) (read November 2, 2026)