If you code for a primary care or multi-specialty practice, the 2027 Medicare Physician Fee Schedule proposal is worth a slow read, not a skim. CMS is floating three additions that touch some of the most commonly billed services in the outpatient world: advance care planning, vaccine reactions, and pediatric speech therapy. None of these are finalized yet, but the placeholder codes and payment estimates already tell you where the agency is headed — and all three would land on the telehealth services list if the rule goes through as written.
Here’s a breakdown of each proposal, along with the payment figures CMS published in Addendum B (based on a provider not participating in a qualifying alternative payment model in 2025).
A New Way to Bill Advance Care Planning
Right now, most practices report advance care planning using CPT 99497 and 99498 — the 30-minute, time-based E/M pair. The catch is that CPT guidelines technically describe these as face-to-face physician or QHP services, even though Medicare has quietly allowed incident-to billing all along. That mismatch between what the code says and what Medicare actually pays for has left a lot of practices under-coding ACP out of caution.
CMS’s fix is to stop patching the confusion and instead build a separate lane for it. Under the proposal, two new HCPCS codes — currently labeled GACP1 and GACP2 — would specifically cover ACP work done by clinical staff under a physician’s direct supervision, in 20-minute increments. The primary code would pay roughly $62, with the add-on running about $50 for each additional 20 minutes. Compare that with the projected 2027 rates for 99497 ($82) and 99498 ($72), and you can see CMS is positioning the G-codes as a lower-intensity, clinical-staff alternative rather than a replacement.
One open question CMS is asking commenters to weigh in on: can a practice bill the physician E/M codes and the clinical-staff G-codes for the same patient on the same day? That answer isn’t locked in yet, and it’s the kind of detail that could materially change how practices structure their time-based coding workflows once the final rule drops.
Getting Paid for Vaccine Reaction Follow-Up
Anyone who’s coded for a busy vaccination clinic knows the drill — a fraction of patients come back with soreness, redness, or a more involved reaction that needs to be worked up. Right now, that extra clinical work often goes uncompensated because there’s no dedicated code for it.
CMS wants to change that with a new add-on code, tentatively labeled GADV1, for evaluating and treating vaccine adverse effects in the office or outpatient setting. It would be billed in 15-minute increments, personally performed by the physician or QHP, and reported alongside standard E/M visit levels (99202–99215, plus the home/residence family 99341–99350).
There’s a small wrinkle worth flagging for anyone tracking this closely: the rule’s narrative text mentions the home/residence codes, but the actual descriptor listed in Table A-D9 only references the office/outpatient setting. That inconsistency suggests CMS is still deciding whether to extend the benefit to home visits — and it’s also weighing whether to allow multiple units per encounter. Payment is estimated at just over $31, contingent on the clinician documenting a clear link between the reaction and the vaccine and ruling out other causes.
Coders who handle vaccine administration billing will want to keep an eye on how this shakes out, since it directly affects how post-vaccination visits get captured going forward.
A Dedicated Code for Pediatric Speech Therapy
The third piece is more of a course-correction. The 2027 CPT Manual is already set to retire CPT 92507 — the long-standing code for individual treatment of speech, language, voice, and auditory processing disorders — in favor of a new time-based code family. But when CMS floated that change, speech-language pathologists pushed back, arguing the new time increments don’t reflect how pediatric therapy sessions actually run.
In response, CMS is proposing a standalone G-code (placeholder: GSLPP) specifically for pediatric patients, billable once per patient per day and added to the “always therapy” list. The agency estimates payment at around $66.
The one detail still up in the air is the age cutoff. One section of the proposed rule caps eligibility at “up to age 21,” while the code table elsewhere lists it as “up to age 18 or 21” — language that reads like CMS hasn’t settled internally on where the line goes. That’s exactly the kind of ambiguity the comment period exists to resolve, and it’s worth tracking alongside other upcoming CPT Medicine section changes.
What This Means for Your Coding Workflow
None of these three codes are final. CMS routinely walks back or reshapes proposals between the draft rule and the final rule, so treat GACP1/GACP2, GADV1, and GSLPP as directional rather than definitive. That said, the direction itself is useful information — it tells you where Medicare sees documentation gaps today, which is often the first sign of where audit scrutiny will land tomorrow.
If your practice bills ACP, administers vaccines, or provides pediatric speech therapy, this is a good moment to start reviewing your current documentation habits against what CMS is describing, rather than waiting for the final rule to force a scramble. And if you want to stay ahead of the broader set of changes coming out of this rule cycle, it’s worth bookmarking a running CPT and HCPCS code update guide so you’re not caught off guard when the final version publishes later this year.
The comment period is still open, so if any of these three proposals affects your specialty directly, that’s the channel to make your case before the ink dries.
Referral Resources
For readers who want to go straight to the primary sources or track the rule as it moves toward finalization:
- CMS Fact Sheet: CY 2027 Medicare Physician Fee Schedule Proposed Rule — CMS’s own plain-language summary of the proposed rule, including the ACP, vaccine reaction, and pediatric SLP provisions.
- CMS-1848-P Rule Page — the official docket, including the full proposed rule text, Addendum B payment files, and comment submission instructions (comment period closes September 14, 2026).
- Federal Register: CY 2027 PFS Proposed Rule — the full legal text as published, useful if you need to cite exact section numbers or regulatory language.
- AMA Summary of the 2027 MPFS Proposed Rule (PDF) — the American Medical Association’s practice-facing breakdown of new G-codes and other coding-relevant changes.
- CMS Physician Fee Schedule Overview — background on how the PFS works and where to find historical conversion factors and rule archives.
