NEMT origin and destination modifiers: the letter codes explained
Origin and destination modifiers are pairs of single letters added to a transport code to show where the trip started and ended. The first letter is the origin and the second is the destination, so RJ means residence to a freestanding dialysis facility. The letters come from Medicare ambulance rules, and Medicaid programs such as Oregon's use them on NEMT claims.
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How origin and destination modifiers work
An origin and destination modifier is two letters placed in the modifier field next to a transportation code. The first letter says where the rider was picked up. The second says where they were dropped off. Medicare’s Claims Processing Manual, Chapter 15, section 30(A), sets the rule for ambulance claims: each letter is an origin or destination code, and the pair forms one modifier. Oregon’s Medicaid NEMT program uses the same letters, and Medi-Cal builds some of its NEMT modifiers from them.
The manual adds one more rule. Some pairs look like other HCPCS modifiers, but when billed with an ambulance transport code they can only mean origin and destination.
The letters
These are the Medicare definitions (Chapter 15, Rev. 13464, issued November 14, 2025), with Oregon’s plain-language notes where they help:
| Letter | Medicare definition | Oregon’s note |
|---|---|---|
| D | Diagnostic or therapeutic site other than P or H when these are used as origin codes | Diagnostic or therapeutic site other than hospital or physician’s office |
| E | Residential, domiciliary, custodial facility (other than 1819 facility) | Nursing home, not skilled nursing facility |
| G | Hospital based ESRD facility | Hospital-based dialysis facility |
| H | Hospital | |
| I | Site of transfer (e.g. airport or helicopter pad) between modes of ambulance transport | Between types of ambulance |
| J | Freestanding ESRD facility | Non-hospital-based dialysis facility |
| N | Skilled nursing facility | |
| P | Physician’s office | Includes non-hospital facility, clinic, etc. |
| R | Residence | |
| S | Scene of accident or acute event | |
| X | Intermediate stop at physician’s office on way to hospital (destination code only) |
Common pairs
These pairs show how the letters combine:
- RP / PR: home to a doctor’s office or clinic, and back.
- RJ / JR: home to a freestanding dialysis center, and back. Use G instead of J when the dialysis unit is hospital-based.
- RH / HR: home to a hospital, and back.
- HN / HE: hospital discharge to a skilled nursing facility, or to a nursing home or other residential facility.
- NP / PN: skilled nursing facility to a doctor’s office, and back.
Each leg gets its own pair, so the ride home reverses the letters of the ride out.
Other modifiers on the same line
Origin and destination letters are not the only modifiers a transport line can carry. States add their own pricing modifiers, and they mean different things from one program to the next:
| Modifier | Where | What it signals |
|---|---|---|
| TN | Arizona | A rural trip that starts outside the Phoenix and Tucson metro areas |
| TK | South Dakota | An additional Medicaid rider on the same trip |
| 59 | South Dakota | A separate trip on the same day |
| UJ | Medi-Cal | A trip between 7 p.m. and 7 a.m. |
| U1, U2, U3 | Texas | Metro or urban, rural, and micro or suburban counties |
Medi-Cal allows up to four modifiers on one line, and they must match the Treatment Authorization Request (TAR).
How states use them
Oregon. OHA’s provider guide (updated December 22, 2025) calls the combination of modifier and procedure code “very important” and tells providers to use a letter pair to show each trip’s pickup point and destination. The pair is entered as a single two-character modifier, never as two one-letter modifiers.
California. Medi-Cal builds a dry run modifier out of the letters. A trip where the provider responded but did not transport is billed with DS, origin D plus destination S, followed by QN. Medi-Cal also pays non-emergency transfers from an acute care hospital to a nursing facility with modifiers HN and QN, and those trips need no TAR. Our dry run entry covers the operations side.
Colorado. The NEMT billing manual has no origin and destination letters. It uses modifiers for other jobs: 76 or 77 for repeat trips on the same day, TK for extra riders in a mobility van, and a set of modifiers on bus tickets under A0110.
Common modifier mistakes
- Reversing the order. RP and PR are different trips.
- Splitting the pair. Oregon says not to enter two one-letter modifiers.
- Using X as an origin. X is destination only.
- Confusing E and N. N is a skilled nursing facility; E is residential or custodial care that is not a skilled nursing facility.
Medicare’s claims system edits ambulance lines for an origin and destination modifier. For what to do when a transport line comes back unpaid, see NEMT claim denials. For the codes these modifiers attach to, see NEMT billing codes, and for the full claim process, see how to bill Medicaid for NEMT.
Frequently asked questions
- What does the modifier RP mean on a NEMT claim?
- Residence to physician's office. R is the residence and P is the physician's office, and the first letter is always the origin. The return trip home is PR. Oregon's guide adds that P includes non-hospital facilities and clinics.
- Do I enter the two letters as one modifier or two?
- As one. Medicare's manual says the pair of letters creates one modifier. Oregon tells providers to enter the pickup point and destination as a single two-character modifier and not as two separate one-letter modifiers.
- Can X be used as an origin?
- No. X means an intermediate stop at a physician's office on the way to the hospital, and Medicare's list marks it as a destination code only. Every other letter can be used in either position.
- Does every state require origin and destination modifiers on NEMT claims?
- No. Oregon tells providers to use the pair to show each trip's pickup point and destination. Colorado's NEMT billing manual lists no origin and destination modifiers at all, and uses modifiers for other things, such as 76 and 77 on repeat trips for one member on the same day. Check the billing manual for each payer.
