HMSA (Hawaii): Service Codes for Authorizations

Last updated: July 27, 2026

A step-by-step guide for clinicians and BCBAs submitting treatment authorizations to HMSA (BCBS Hawaii)

When you submit a treatment authorization, Alpaca saves you time and reduces errors by reading the requested service codes straight out of the treatment plan and pre-filling them for you to review — no manual re-typing of CPT codes and units. For HMSA / Hawaii Blue Cross Blue Shield clients there's an extra layer: you also choose the right credential modifiers, and Alpaca enforces HMSA's prior-authorization rules.

This guide walks through that flow end to end, with the HMSA specifics called out.

Who this applies to: the service-code extraction runs for any payer on a treatment authorization (First Treatment or Further Treatment). This guide focuses on HMSA (BCBS Hawaii) clients, who get the extra layer — a Modifiers column plus HMSA prior-authorization rules: required credential modifiers, unit caps, and no mixing of assessment and treatment codes on one request. For non-HMSA payers the table is identical minus the modifier handling.

Step 1 — Start a request from Care Readiness

Open the client and go to the Care Readiness tab, then click Create Request.

The Create Request sheet opens to step 1 · Create Request.

Step 2 — Configure the request

Fill in the three fields:

  1. Patient Plan — select the client's HMSA (BCBS Hawaii) insurance card.

  2. Request Type — choose Prior Authorization.

  3. Authorization Type — choose First Treatment Authorization (for a new client starting therapy) or Further Treatment Authorization (to continue an expiring authorization).

Then set the Authorization Start Date and click Create.

💡 Service-code extraction runs for treatment authorizations specifically. Assessment authorizations (CPT 97151/97152) follow a different path — and, per HMSA's rules, assessment and treatment codes can't go on the same request.

Step 3 — Attach the treatment plan and let Alpaca read it

On the next step (2 · Upload Information), attach the client's treatment plan under Required Documents → Treatment Plan/Plan of Care. You can Upload Document or select from existing files.

As soon as the plan is attached, Alpaca reads it ("Reading treatment plan… Extracting requested units from the treatment plan…") and, within a few seconds, the Requested Service Codes table fills in automatically with the CPT codes, hours, frequency, and units it found in the plan's service-codes table.

Notice the helper text — "Auto-filled by AI from the treatment plan. Review the requested units and select any modifiers before submitting." — and that for HMSA clients the table is subtitled "Units, hours and modifiers submitted to the payor" and includes a Modifiers column. A "rows missing required fields" badge flags anything still needing input (like Place of Service).

A few things to know about this table:

  • It's auto-filled, but you're in control. Everything is editable — the AI is giving you a head start, not the final word.

  • If the plan has no service-codes table, you'll see "No service-codes table was found in the treatment plan — add the requested codes manually below," and you can add codes by hand.

  • Only ABA CPT codes are pulled in (97151, 97152, 97153, 97154, 97155, 97156, 97157, 97158, plus 0362T / 0373T / T1026). Modifiers are handled separately (see the next step).

Step 4 — Review the units and choose modifiers (HMSA)

This is the part that's specific to HMSA. Review each row and confirm it matches what you intend to request:

  • Service Code — the CPT code and its friendly name (e.g., 97153 — Direct Session)

  • Hours, Frequency (Weekly / Monthly / Authorization), and the calculated Auth Units

  • Place(s) of Service — e.g., 11 — Office, 12 — Home, 03 — School, 02 — Telehealth

  • Modifiers — (HMSA only) the credential modifiers sent to the payer

Click Edit to open the row editor and adjust hours, frequency, places of service, notes, and modifiers; use Add to insert another CPT code.

In the editor, each CPT row has its own Hours Requested, Frequency, Place(s) of Service, auto-calculated Auth Units, and Modifiers selector. Place of Service is required, so fill it in for each row before submitting.

✅ HMSA credential modifiers. HMSA requires a credential modifier — HM, HN, HO, or HP — on treatment codes. Alpaca adds sensible defaults based on the clinician's credentials, but you can choose alternatives here. If a treatment code is missing one, you'll get a gentle heads-up before submitting (you can still proceed).

Step 5 — Validate and submit

When you submit, Alpaca runs two quick safety checks before anything goes to the payer:

  1. Plan match. If your edited codes differ from what's in the treatment plan, you'll see a note explaining the difference — "The payor receives both the treatment plan and these requested codes. If the plan is incorrect, update and re-upload it."

  2. HMSA rules. Alpaca checks HMSA's payer rules, such as:

    • No assessment + treatment on the same request (97151/97152 can't be combined with treatment codes).

    • Unit caps (e.g., 97151 is capped at 60 units per authorization).

    • Credential modifier present on treatment codes.

You'll then see one of two prompts:

  • "Cannot submit — please fix" — there's a critical issue (like a unit cap or assessment+treatment mix) that must be corrected first. Make the change and try again.

  • "Before you submit" — there are only non-critical warnings. You can review them, go back and Make changes, or choose Submit anyway.

Once it passes, the request is submitted with your reviewed codes, units, and modifiers. You can see the requested codes on the Prior Authorization Details view afterward:

Quick recap

  1. Care Readiness → Create Request.

  2. Select the HMSA plan, Prior Authorization, and a treatment authorization type; set the start date; Create.

  3. Attach the treatment plan — Alpaca auto-extracts the requested service codes.

  4. Review units and choose modifiers (HM / HN / HO / HP for HMSA).

  5. Submit — Alpaca validates HMSA's rules and flags anything that needs attention.

Good to remember:

  • The extraction is a starting point. Always review the units and modifiers before submitting — you have the final say.

  • The Modifiers column and HMSA rule checks appear for HMSA clients specifically. Other payers see a simpler units-only version of this table.

  • Critical issues block submission; warnings don't. If you can override it, it wasn't critical.

Questions, or the table didn't populate the way you expected? Reach out to support and we'll take a look.