NEMT Origin and Destination Modifiers: The Two-Letter Codes on Every Trip

What origin and destination modifiers are

Origin and destination modifiers tell the payer where a ride began and where it ended. They come from Medicare’s ambulance billing rules. Section 30(A) of chapter 15 of the Medicare Claims Processing Manual, in the chapter’s current revision (13464, issued November 14, 2025), builds each modifier from two letters. CMS maintains the list of valid letters. The first letter is the origin. The second is the destination. Together they form one two-character modifier.

Medicare requires one on every ambulance trip. Many Medicaid programs use the same letters on non-emergency rides too. Indiana, Minnesota, and Oregon tell providers to put them on transportation claims, and Ohio lists the pairs it pays without manual review for each wheelchair van and ambulance code. The modifier sits next to the trip’s billing code, such as T2003 or A0130. See NEMT billing codes for the codes themselves.

Every origin and destination letter

Letter	Official meaning	What it covers on a NEMT ride
D	Diagnostic or therapeutic site other than P or H when these are used as origin codes	Other treatment sites. Ohio lists a drug and alcohol rehab center, an ambulatory surgery center, an independent diagnostic testing facility, and a medical equipment supplier.
E	Residential, domiciliary, custodial facility (other than an 1819 facility)	A care home that is not a skilled nursing facility. Ohio’s example is an intermediate care facility for people with intellectual disabilities.
G	Hospital-based ESRD facility	A dialysis unit located in a hospital
H	Hospital	A hospital
I	Site of transfer between modes of ambulance transport, such as an airport or helicopter pad	Rare on NEMT rides. Ohio uses it to build workplace and school pairs.
J	Freestanding ESRD facility	A dialysis center not located in a hospital
N	Skilled nursing facility	A skilled nursing facility (the 1819 facility the E letter excludes)
P	Physician’s office	Ohio and Oregon include clinics. Ohio also includes other practitioners’ offices, such as a dentist or physical therapist.
R	Residence	The rider’s home, permanent or temporary
S	Scene of accident or acute event	An emergency location. It rarely fits a scheduled ride.
X	Intermediate stop at physician’s office on the way to hospital	Destination only, never first. Built for ambulance trips.

How to build the modifier

1. Origin first. Write the pickup letter, then the drop-off letter. Home to a doctor’s office is RP.
2. One modifier, two letters. Oregon’s guide says to enter the pair as a single two-digit modifier, never as two separate one-letter modifiers.
3. Flip it for the ride back. The return from the doctor’s office is PR.
4. Put it on every line your payer requires. Indiana wants it on the base rate line and the mileage line.
5. Leave room for other modifiers. Box 24D of the CMS-1500 holds up to four two-character modifiers, under the NUCC instructions (version 13, July 2025). See the CMS-1500 for NEMT.

Indiana does not use origin and destination modifiers on prior authorization requests. They go on the claim only.

Some pairs look like other HCPCS modifiers. RR, home to home, is also the national modifier for renting medical equipment. Medicare’s manual says that when a pair is billed with an ambulance transportation code, it can only mean origin and destination.

Worked examples

Trip	Going	Coming back
Home to a freestanding dialysis center	RJ	JR
Home to a dialysis unit inside a hospital	RG	GR
A care home that is not a skilled nursing facility to a doctor’s office	EP	PE
Skilled nursing facility to a hospital appointment	NH	HN
Home to an imaging or surgery center	RD	DR
Hospital discharge to home	HR	None
Clinic to home on a will-call return	PR	None

A billing example from Indiana. A walk-on rider goes 14 loaded miles from home to a freestanding dialysis center. Indiana’s module (version 6.1, policies as of September 1, 2023) puts RJ on both lines:

Line	Code	Modifiers	Units
1	T2003 (base rate)	RJ	1
2	A0425 (mileage)	U3 and RJ	14

On the ride home the pair becomes JR.

State rules that change the pattern

Ohio. The appendix to rule 5160-15-28, in effect since August 1, 2026, lists the pairs Ohio pays without manual review for each code. For wheelchair van base (A0130), mileage (S0209), and attendant (T2001), home to home (RR) is not on the list. Neither are skilled nursing facility to care home (NE) or the reverse (EN). Ohio also adds its own codes:

Ohio code	Meaning
U4	Workplace, paired with a transfer code. Workplace to a doctor’s office is U4 plus IP.
U7	School, paired the same way
U5	A point not otherwise specified. It needs no second code but always goes to manual review.
U6	The medical service was not available when the vehicle arrived
UA and UB	UA marks an additional trip by the same person on the same day, in the same type of vehicle, to or from the same type of place. UB marks a second additional trip.
U3	A wheelchair van service given in an ambulance vehicle, used only with A0130, S0209, and T2001

Minnesota. The DHS rate page for rides arranged by MTM-MNET, SmartLink, and county or tribal agencies, revised July 31, 2026, requires an origin and destination pair on every unassisted (Mode 3) and assisted (Mode 4) ride. That covers the base line, A0100 or T2003, and the S0215 mileage line. Minnesota builds the pairs from the same Medicare letters. When a member takes more than two rides in a day, the extra base lines also carry a repeat service modifier.

Oregon. The provider guide, last updated December 22, 2025, adds plain-English notes to the national letters. P includes a non-hospital facility or clinic. E includes a nursing home that is not a skilled nursing facility.

Medi-Cal. A dry run, where the vehicle arrives but the rider is not transported, bills the modifier DS followed by QN. DS is built from the origin letter D and the destination letter S.

Wrong pairs and the denials they cause

These are the mistakes to check for before you submit:

• G and J swapped. The address decides it: a dialysis unit in a hospital is G, a freestanding center is J.
• E and N swapped. E is a care home that is not a skilled nursing facility, such as an intermediate care facility. N is a skilled nursing facility.
• P, D, and H mixed up. A practitioner’s office or clinic is P, an imaging or surgery center is D, and a hospital is H.
• The return trip not flipped. Both legs billed as RJ looks like two trips to dialysis.
• Two single letters. R and J as separate modifiers instead of RJ.
• Ambulance letters on a van ride. S or X on a scheduled ride, or X in the first position.
• Mileage line left bare. The base line has the pair, but the mileage line does not.
• A pair outside the payer’s list. In Ohio, a pair that is not on the appendix list goes to manual review.
• A pair that does not match the trip record. The addresses on the trip log and authorization must show the same two places.

On a remittance, modifier problems show up under standard adjustment reason codes. Code 4 reads “The procedure code is inconsistent with the modifier used.” Code 16 reads “Claim/service lacks information or has submission/billing error(s).” Code 182 reads “Procedure modifier was invalid on the date of service.” See claim adjustment reason codes and NEMT claim denials for how to fix and resubmit.