TP Modifier: Unloaded Vehicle Miles and When They Are Ever Paid

What the TP modifier means

CMS lists TP in the national HCPCS code set as “Medical transport, unloaded vehicle.” It entered the code set on April 1, 2002. The October 2026 quarterly file gives it coverage code I, which means Medicare does not pay it.

TP goes on a mileage line, such as S0209 for a wheelchair van or T2049 for a stretcher van, to say those miles were driven empty. These are the miles most owners call deadhead miles: out to the first pickup, between trips, and back to the lot. Their opposite is loaded miles, with the rider on board, which is what a mileage code normally counts.

The code set says nothing about when TP pays. Each payer decides whether it takes TP at all, on which codes, and after how many free miles. Some never pay it, a few pay it in narrow cases, and two give the same letters a different meaning.

Why Medicare and most Medicaid programs do not pay it

Medicare spells out why it refuses empty miles on ambulance claims. Section 20.2 of chapter 15 of its claims processing manual (chapter revision issued November 14, 2025) says mileage charges must be for loaded mileage only, from the pickup of the patient to arrival at the destination. Medicare presumes you set your base charge and your loaded mileage rate to cover every unloaded mile, and it denies separate charges for unloaded miles.

Medicaid starts from the same place. CMS’s Medicaid Transportation Coverage Guide (SMD 23-006, September 28, 2023) says no load miles generally cannot be paid as a direct service or an administrative activity, and that includes the drive back after a rider does not show. States may build the cost into their payment rates instead.

Since that date, a state may also pay unloaded miles separately in one narrow case: the most appropriate and economical provider would face extraordinary costs to reach the rider, costs the usual rate does not cover. The state must first submit a state plan amendment to CMS with coverage and payment pages. Ask your state Medicaid agency whether it has one before you plan on TP pay.

Which payers pay for empty miles

As of October 2026, each of these five payers pays some empty miles, and only the first three want TP on the line:

Payer	When empty miles pay	How you bill them
Wisconsin fee-for-service (ForwardHealth)	Past the first 20 empty miles to a pickup, with no one else on board	S0209 TP or T2049 TP
North Dakota Medicaid Expansion (BCBSND)	Past the first 15 miles, when you drive more than 15 miles outside your home town	Mileage code with TP, for one rider
South Country Health Alliance (Minnesota)	Contracted companies only, on the drive to pick the member up	The mode’s TP line, with TP in the second position
North Dakota Medicaid	Only with the department’s approval, asked for by email	Total miles on the claim, approval email attached
South Dakota community transportation	Trips outside city limits of 21 miles or more one way, in two cases	Empty and loaded miles together on one S0215 line

Medicare and Arizona’s fee-for-service program pay none. Chapter 14 of the AHCCCS billing manual (revised July 31, 2026) says a provider may not submit any claim for unloaded mileage, including a trip to pick up a member’s prescription. See Arizona.

Wisconsin. State rule DHS 107.23(1)(c)5 pays a specialized medical vehicle (SMV) for unloaded miles only when it drives more than 20 miles, by the shortest route, to pick up a member, with no other passenger in the vehicle. The SMV handbook (published policy through September 30, 2026) puts TP on S0209 for a wheelchair van and T2049 for a stretcher van. You record every empty mile on the SMV trip ticket (form F-01050) but bill only the miles past 20, so a 35-mile empty drive bills 15. On a shared ride the empty miles pay once, and the drive back to base never pays. This is the fee-for-service rule. Claims for most members’ rides go to the NEMT manager Wisconsin DHS contracts with, which pays under its own contract. See Wisconsin.

North Dakota. The NEMT manual (updated January 2026) covers only miles with the member in the vehicle, though the department may approve unloaded miles at its discretion. Email the NEMT Administrator with the authorization from the Customer Support Center and the number of empty miles. If the department approves, you bill the total miles on the claim and attach the approval email; the manual names no modifier for them. Medicaid Expansion, run by BCBSND, works differently. Its provider page lists TP lines for S0215, A0170, S0209, and T2049. TP is billable only when you travel to a place more than 15 miles outside the city or town you are based in, for a pickup or drop-off, only after the first 15 miles, and for one member when several ride. Your BCBSND contract sets the rate. See North Dakota.

South Dakota. The community transportation manual (updated August 2026) pays empty miles on trips outside city limits of 21 miles or more one way, in two cases: the driver returns to where the trip started after a drop-off, or drives to a hospital or nursing facility to pick up a member being discharged. Only the miles between the two cities count, never in-town driving. You bill them on S0215 together with the loaded miles, on one line, and for one rider however many ride. TP is not on the state’s list of authorized modifiers effective July 1, 2026. This rule covers community transportation, which only a government entity, a nonprofit registered with the South Dakota Secretary of State, or a secure medical transportation provider also enrolled for community transportation may bill. See South Dakota.

South Country Health Alliance. This Minnesota health plan pays unloaded miles to contracted companies only, under Chapter 27 of its provider manual (last updated February 27, 2026). You bill all the empty miles on the drive to pick the member up, on a round trip or a one-way trip. You may not bill the empty drive to the clinic for the return leg, or the drive away after dropping the member at home. The one exception is a one-way trip that starts at the clinic. Each mode has its own TP line: A0100 TP for a taxi or common carrier, T2003 TP for ambulatory, S0209 TP for wheelchair, T2049 TP for stretcher, and S0215 TP for protected transport. Your trip log has to show where the driver started, or the odometer readings, for the empty miles. See South Country Health Alliance.

When TP means something else

Because each payer picks its own use for TP, the same two letters can mean something other than empty miles:

• New Jersey. The Medicaid fee-for-service schedule (update of September 1, 2026, with rates effective July 1, 2026 and proposed until CMS approval) lists A0425 TP as “per loaded mile one way trip,” paid at contract pricing. It also lists A0422 TP as oxygen on a mobility assistance vehicle (MAV) trip, $12.00 per occurrence. Neither line is for empty miles. See New Jersey and A0425.
• IEHP in California. IEHP’s billing guidelines, posted May 1, 2024, use T2001-TP, A0130-TP, and T2005-TP to bill a no-show or cancellation on a door, wheelchair, or gurney trip. Your contract with IEHP sets what those lines pay.

A worked example: one Wisconsin wheelchair van trip

A wheelchair van leaves its dispatch point and drives 32 miles empty, by the shortest route, to pick up a member. It carries the member 18 miles to a clinic, then drives back to base empty. You bill this trip to ForwardHealth, so the fee-for-service rules apply. The A0130 base rate includes the first five loaded miles, mileage bills in exact tenths of a mile, and every SMV code carries a trip number modifier, here U1.

Line	Code and modifiers	Units
Empty miles past the first 20	S0209 with U1 and TP	12
Base rate, with the first 5 loaded miles	A0130 with U1	1
Loaded miles past the first 5	S0209 with U1	13

The first 20 empty miles and the drive back to base pay nothing. Had the dispatch point been 20 miles away or less, the claim would have no TP line at all. Each line pays up to ForwardHealth’s maximum fee for that code and modifier on the date of service. For how loaded miles are counted and rounded in other programs, see NEMT mileage billing.

How to bill TP without a denial

1. Find TP on your payer’s code list. Look in the fee schedule, broker rate sheet, or plan manual. If your mileage code has no TP line, the payer either pays no empty miles or wants them billed another way, as North Dakota Medicaid and South Dakota do. A code and modifier pair it does not accept can deny with claim adjustment reason code 4, “The procedure code is inconsistent with the modifier used.”
2. Check what TP means there. In New Jersey it marks a loaded mile, and at IEHP it marks a no-show.
3. Record where each empty drive starts. Write the starting point and odometer readings on the trip record. South Country asks for the driver’s start location or odometer readings, and Wisconsin asks for unloaded miles on its trip ticket.
4. Subtract the free miles. Bill only the empty miles past 20 in Wisconsin fee-for-service and past 15 with BCBSND. South Country has you bill all the empty miles to the pickup.
5. Bill one rider. When several members ride, Wisconsin, BCBSND, and South Dakota pay the empty miles once.
6. Leave out the drive home unless your payer lists it. Wisconsin and South Country never pay it, and South Dakota pays it only on trips outside city limits of 21 miles or more one way.
7. Put TP where the payer wants it. South Country wants TP in the second modifier position, after the origin and destination modifier. Wisconsin’s handbook example bills S0209 with U1 and TP.