What is a spare ratio, and how many backup vans does a NEMT fleet need?
A spare ratio is the number of spare vehicles divided by the number needed for peak service, shown as a percentage. The FTA holds bus fleets with 50 or more fixed-route vehicles to 20 percent and sets no figure for smaller ones. A small NEMT fleet should size its spares from its own downtime, because inspections, repairs, and lift failures all take vans out of service.
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How the spare ratio is calculated
FTA’s award management circular (C 5010.1F, dated November 1, 2024) defines the spare ratio as the total spare vehicles divided by the vehicles required for annual maximum service. Its own example: 100 vehicles needed at peak plus 20 spares, 120 in all, is a 20 percent spare ratio. The ratio is figured for the whole fleet, not by vehicle type.
Peak here means the most vehicles on the road at once during the busiest week and day of the year, leaving out unusual days and special events. The count leaves out vehicles bought for future growth, vehicles already replaced and waiting for disposal, and any contingency fleet held for emergencies.
The National Transit Database glossary says what spares are for: covering routine and heavy maintenance, covering breakdowns and accidents, and keeping scheduled service running.
The FTA guideline
For transit agencies running 50 or more fixed-route buses at peak, FTA expects spares to stay at or under 20 percent. Below 50, it names no percentage and expects a reasonable number given the fleet’s size and mix of vehicle types. An agency that goes over because new buses arrived can get a deviation, generally for no more than two years.
The guideline binds FTA grant recipients, not private NEMT companies. It is still a sensible upper bound, because a fleet carrying far more than 20 percent spares is paying insurance and registration on vehicles that rarely earn.
What takes NEMT vans off the road
Spares cover the days a van cannot run. For a NEMT fleet, those come from four places:
| Cause | What the rules say |
|---|---|
| Broker inspections | MTM Health, Virginia’s fee-for-service broker for rides starting October 1, 2026, inspects every vehicle before it carries members and again every six months; a noncompliant vehicle can be pulled from service |
| Annual safety checks | CareOregon wants proof of a safety inspection done in the past year by an ASE-certified mechanic |
| Lift failures | A public transit agency must pull a van whose lift fails before that van’s next day of service; without a spare they may keep it running only 5 days (areas of 50,000 people or fewer) or 3 days (larger areas) |
| Breakdowns and accidents | New York no longer lets providers lease a van from another provider after a breakdown; the provider alerts the broker, which finds another provider |
The lift rule in 49 CFR 37.163 applies to public entities, but it shows how one broken lift can take a van off the schedule by the next morning. The wheelchair lift failure guide and the breakdown guide cover what to do on the day. CareOregon’s manual also asks every provider, as part of its adverse weather and disaster planning, for a contingency and backup plan for members who may be picked up excessively late.
Sizing spares for a small fleet
Work from your own records rather than a percentage:
- Find your peak. Count the most vehicles you need on the road at once. The fleet size calculator does this from your trip volume.
- Log downtime. For the past year, list every day each van was out: inspections, scheduled maintenance, repairs, accidents, and lift problems.
- Look at the worst days. Find the most vans you lost at the same time. Averages hide the Monday when two vans failed together.
- Match the service type. A spare sedan cannot run a wheelchair trip. If you run a mixed fleet, make the spare the vehicle type you can least afford to lose.
As an example, a fleet that needs eight vehicles at peak, five of them wheelchair vans, might keep one spare wheelchair van. That is 1 divided by 8, a 12.5 percent spare ratio, and it can cover an ambulatory trip as well as a wheelchair one. The vehicle maintenance guide covers scheduling service so inspections do not all fall in the same week.
Keeping spares ready in HealthRide
HealthRide has drivers check their van right in the app at the start of every shift, and reminders keep credential expirations from sneaking up on you. The fleet page covers both.
Frequently asked questions
- Does the FTA 20 percent limit apply to a NEMT company?
- No. It is a guideline for transit agencies that receive FTA grants, applied to bus fleets with 50 or more vehicles in peak fixed-route service when FTA reviews an award to buy or replace vehicles. For fleets under 50, FTA sets no number and expects a reasonable count. It is still a useful yardstick for thinking about backups.
- Can I borrow a van from another provider when one of mine breaks down?
- Check your program first. New York's Medicaid Transportation Policy Manual (effective August 25, 2023) no longer lets one provider subcontract trips to, or lease vehicles from, another after a breakdown. When a provider is short of vehicles, it must alert the broker so the broker can reassign the trips.
- Does a spare van need a broker inspection too?
- Yes, if it will ever carry members. MTM Health's Virginia handbook requires every vehicle to be inspected before it transports members and re-inspected every six months, and vehicles out of compliance can be pulled from service. A backup van that is not on file cannot stand in for one that is.
- Is a 10 percent spare ratio enough for a small fleet?
- It can be, depending on your repair history. As a reference point, the Duval County, Florida transportation disadvantaged plan requires its operators to keep one backup vehicle for every ten in service, which is 10 percent. With fewer than ten vans, one spare is already more than 10 percent, so the real question is which vehicle type the spare should be.
