Detox and Residential H Codes: Read the Grid, Then Read Your State

The last post here argued that most H codes are a name and little more. CMS gives H0031 five words, and the states supply everything a claim actually needs.

The detox and residential codes look like the exception. Their descriptors carry real information: where the patient is, how intense the care is, how long the stay runs, and whether the rate includes the bed. Read in order, they form a grid.

That grid is worth knowing. It is also the part your state is free to ignore, and at least one state does.

The detox grid

Seven codes cover detox, H0008 through H0014. Each one answers two questions: where the patient is, and whether the care is acute or subacute.

Pick the row from the setting and the column from the intensity, and the descriptor agrees with you. None of the seven says what a unit is, though, so whether you bill by the day or by the stay is your state’s call, as it is for most of the range.

The residential codes

Four more cover residential treatment, and all four are billed per diem.

• H0017: residential treatment in a hospital program, without room and board
• H0018: short term residential outside a hospital, without room and board
• H0019: long term residential for care that is neither medical nor acute, where stays typically run longer than 30 days, without room and board
• T2048: the same long term stay as H0019, with room and board included

Two more show up in state maps even though their names say nothing about residential care: H2034, halfway house services by the day, and H2036, an alcohol and drug treatment program by the day.

Why most of them say without room and board

The split between the bed and the treatment follows how Medicaid pays. In a 2017 letter to state Medicaid directors, CMS said its substance use waiver option “does not allow for room and board payments in those facilities” unless they qualify as inpatient facilities.

So a per diem under H0017, H0018 or H0019 pays for treatment, not the bed. T2048 is the code for a long stay whose rate includes both, and the two are not interchangeable.

Same code, different job

Here is where the grid stops helping. States map the ASAM levels of care onto these codes, and they do not map them the same way.

Virginia’s addiction treatment program, ARTS, lists its residential levels like this:

The rows from 3.3 up also carry revenue code 1002, and a revenue code means an institutional claim rather than a professional one.

Read that table against the grid. In Virginia, H0010 with HB is an adult in high intensity residential treatment, whatever its national descriptor says. H0011, the acute detox code, is the most intensive inpatient level. And low intensity residential bills under a code whose national name is halfway house.

Nevada reads the same codes much closer to their names. A January 2025 Nevada Medicaid notice opened H0011, H0018 and H0019 to substance use treatment providers, including residential programs in an institution for mental diseases. Each is limited to one unit per day and needs prior authorization.

Two states, one code set, two different readings of it. A biller trained on one state’s map and moved to the other would misread these codes on day one.

The map is moving

ASAM has published a fourth edition of its Criteria, and it reshapes the levels these maps are built on. It removes level 3.3, and it folds level 3.2 withdrawal management into level 3.5.

States are moving at different speeds. A 2025 transition guide hosted on Colorado’s Medicaid agency site walks level 3.2 withdrawal management programs into the new structure, and tells them plainly that “Colorado is not losing a level of care.” The version of Virginia’s table quoted above was posted in May 2024, and it still has a 3.3 row.

Any map you rely on needs a date and a check that it matches the edition your state uses now.

Seventeen codes, one short name

One more trap, and this one lives on your screens rather than in the rules.

Every HCPCS code also has a short descriptor of 28 characters or fewer, and systems that are short on space show that version instead of the long one. CMS gives seventeen active codes, H0004 through H0020, the identical short descriptor: “Alcohol and/or drug services.” As many codes share no other short descriptor in the file.

That covers every detox code, all three residential H codes, and H0004, which is counseling and therapy. On a screen that shows short descriptors, H0010 and H0013 look the same. Check the code, never the name.

Medicare pays none of these

Like every H code, all of these carry Medicare coverage code I, not payable by Medicare. So do T2048, H2034 and H2036. They are Medicaid codes, and a residential stay for a patient who has both Medicare and Medicaid needs its own check against your state manual.

Before you bill a stay

• Find your state’s map from ASAM level to code. Note the date on it.
• Confirm which edition of the ASAM Criteria it follows. A map from before your state’s switch will carry levels that no longer exist.
• Note the modifiers it requires. Virginia uses HB for adults, HA for adolescents and TG for level 3.3.
• Check the claim type. Some levels go on a professional claim and some on an institutional claim with a revenue code.
• Check daily limits and prior authorization. Nevada allows one unit per day and requires authorization.
• Keep room and board out of the rate unless the code you bill says it is included.
• Read the code, not the short name.

Every code named here has its own page in the HCPCS lookup with its official descriptor. HB and HA are explained in the behavioral health modifiers post, and the H codes as a whole in the H codes post.

Sources

• CMS HCPCS quarterly update. Long and short descriptors and Medicare coverage codes, checked against the July 2026 file.
• CMS, State Medicaid Director letter 17-003, Strategies to Address the Opioid Epidemic, November 2017.
• Virginia DMAS, ARTS service types and procedure codes, posted May 2024.
• Nevada Medicaid, web announcement 3541, January 2025.
• IRETA, Major Changes in the Fourth Edition of The ASAM Criteria.
• Colorado transition guide, ASAM level 3.2 withdrawal management to 3.5, 2025.
• Your own state Medicaid manual, which is the only authority for your claims and overrides every national reference, including this one.

Reference information only. Not billing advice. ASAM level mappings, units, modifiers and limits vary by state, by program and by plan. Verify against your own state Medicaid manual before you file.