S9122 HCPCS Code: Home health aide or certified nurse assistant (Units, EVV, Rates, Denials)

S9122 is “Home health aide or certified nurse assistant, providing care in the home; per hour.” It is billed per hour and covers hands-on aide care in the home by a home health aide or CNA. Medicare does not pay it; some Medicaid programs, commercial plans and long-term care insurers use it. EVV is required when Medicaid pays for the service as personal care or home health; private payers usually don’t require it.

Units and rounding

One unit is one hour. Partial hours follow the payer’s manual; some payers pay quarter-hour fractions and others only full hours. Convert minutes in the units calculator.

Modifiers you will see

• U1–U9: State-defined; often distinguish programs (waiver vs state plan), service levels or provider types

Modifier meanings are set by each state and payer, so check your provider manual. See home care billing modifiers.

Typical rates

Hourly aide rates differ by payer and state. Each state program and managed-care plan sets its own rate, so use your state’s current fee schedule. Check what is left of an hour after wages and overhead with the Medicaid hour margin calculator.

Common denial reasons

• Hours exceed the authorization
• Missing or mismatched EVV visit (Medicaid)
• Aide credentials don’t meet the payer’s requirement
• Service date outside the authorization period

Related codes

• T1021: Home health aide or certified nurse assistant, per visit
• G0156: Services of home health/hospice aide in home health or hospice settings, each 15 minutes
• T1019: Personal care services, per 15 minutes

Source

CMS HCPCS Level II code set (quarterly update). Confirm the exact descriptor and any state-specific unit definition in your payer’s billing manual. Last reviewed November 6, 2026.

General information, not billing or legal advice. Check your state Medicaid agency’s current fee schedule and provider manual.