G2211 Retires: The Modifier B1/B2 Billing Guide for 2027

CMS's November 4 Final Rule Turns Your Flat $17.37 Add-On Into a 16% or 32% Swing on Every E/M Claim

By Team Rcmaxis  ·  November 6, 2026  ·  11 min read

G2211 paid a flat $17.37 in 2026, no matter whether you billed it next to a 99213 or a 99215. That math is gone. CMS finalized the CY 2027 Medicare Physician Fee Schedule on November 4, 2026, and buried inside 1,500-plus pages of rate cuts and RPM overhauls is a change that touches almost every primary care, behavioral health and chronic-care claim you file: G2211 stops existing as a standalone add-on code on January 1, 2027. It becomes modifier B1, worth a 16% bump on the E/M payment itself. A new sibling, modifier B2, pays 32% for practitioners inside a Medicare Shared Savings Program ACO or a LEAD Model Participant Provider.

That's not a cosmetic rename. Moving from a flat dollar amount to a percentage changes who wins and who loses on every single claim, and it changes how your charge capture, superbills and EHR order sets need to work starting in about eight weeks. If your practice billed G2211 even a few hundred times in 2026, you need to run this math before January 1, not after your first denial batch comes back.

What G2211 Paid in 2026, and What Modifier B1 Pays Instead

Under the 2026 rules, G2211 carried a work RVU of 0.33 and a non-facility total RVU of 0.52, which worked out to a national payment of roughly $17.37 at the $33.4009 conversion factor, before any geographic adjustment. That figure didn't move based on which E/M level you billed alongside it. A straightforward established-patient visit (99213) and a high-complexity one (99215) both triggered the same flat $17.37, as long as the visit met the longitudinal-relationship standard.

Modifier B1 breaks that pattern on purpose. Instead of a flat add-on, it's a 16% increase applied directly to whatever the E/M code itself pays. Run the two illustrative scenarios side by side, using 2026 national non-facility E/M payment estimates (99213 at $95.19, 99215 at $192.39, per fastRVU and PayerPrice fee-schedule data) and holding those same underlying RVUs flat while swapping in CMS's finalized CY 2027 non-APM conversion factor of $32.63, to isolate just the conversion-factor and modifier-mechanics effect. Treat the dollar figures below as an illustration, not a locality-adjusted quote, since your actual payment depends on your GPCI and on any 2027 RVU updates CMS applies under its new practice-expense methodology.

That split is the whole story in one table. A practice whose G2211 volume skews toward quick, lower-level established visits, think high-volume primary care or urgent care-adjacent panels, is going to see its per-visit complexity bonus shrink under B1, not grow. A practice whose visits run higher-acuity, geriatrics, endocrinology, oncology survivorship, multi-condition chronic care management, comes out ahead. Don't assume the rename is revenue-neutral for your payer mix. Pull your own 2026 G2211 claims by E/M level and re-run this exact table with your actual volumes before you build a 2027 budget.

Modifier B2: The ACO and LEAD Model Path, and Why It's Not Just a Billing Decision

Modifier B2 is the second half of this change, and it's where the stakes go well past a billing office. It pays 32% instead of 16%, but only for practitioners participating in a Medicare Shared Savings Program ACO or a LEAD Model Participant Provider. Using the same illustrative 99215 scenario above, a 32% bonus on a ~$187.95 base E/M payment works out to roughly $60.14, pushing the total claim to around $248.09, well above either the old flat G2211 rate or the new B1 rate.

Here's the part a billing team can't decide alone: CMS's fact sheet is explicit that B2 use is voluntary and can be billed for every beneficiary that practitioner serves, not only patients formally assigned or aligned to the ACO. That sounds like a straightforward revenue win, until you read the next sentence. Every B2 claim counts toward that practitioner's beneficiary assignment, toward the ACO's financial benchmarks, and toward performance-year expenditures used in the shared-savings calculation. Billing B2 more aggressively can pull in more unassigned beneficiaries and shift the spending baseline your ACO gets measured against, for better or worse depending on how your population mix nets out.

Who Actually Qualifies for B1 or B2

The underlying clinical standard hasn't changed: both modifiers still attach to the same "ongoing, longitudinal relationship with the patient for a serious or complex condition" test that governed G2211, reported against office and outpatient E/M visits (99202-99215), and, following the 2026 expansion, against home or residence E/M visits (99341-99350). New patients can qualify if the visit is genuinely establishing that ongoing relationship going forward, not just a one-off consult.

The modifier 25 interaction carries forward too, and it's a common source of denials worth double-checking in your scrubber rules. As of the current CMS guidance, the complexity modifier generally isn't payable when the base E/M is billed with modifier 25 for a same-day procedure, with a specific carve-out for qualifying Medicare Part B preventive services like an annual wellness visit or vaccine administration. A same-day minor procedure with modifier 25 still blocks it. If your 2026 claims data shows G2211 riding alongside modifier 25 outside that preventive carve-out, expect the same denial pattern to carry over to B1 and B2 claims in 2027, just under a different code.

Your G2211-to-Modifier Transition Checklist

Most of the actual transition work is mechanical, but it has to happen before claims start going out under the new rule, not during a denial cleanup project in February. Treat this as a punch list with an owner and a date next to each line, not a someday project.

The Claim-Rejection Risk of Getting the Timing Wrong

The most immediate risk isn't a coding judgment call, it's a timing error. G2211 is retired as a billable HCPCS code effective with dates of service on or after January 1, 2027. Any claim line still carrying the standalone G2211 code for a 2027 date of service is billing a code that no longer exists in the active fee schedule, which is a clean setup for an automatic claim-edit rejection or an unrecognized-code denial, not a payment adjustment you can appeal after the fact. EHR systems and clearinghouses that haven't updated their code libraries by January 1 will keep offering G2211 as a selectable option well past its retirement date unless someone actively removes it, and a coder working from habit will click it.

Watch your MAC's and major commercial payers' Q4 2026 and Q1 2027 crosswalk bulletins specifically for this transition. CMS final rules routinely leave the detailed claims-processing instructions, including exact modifier-to-code pairing edits, to follow-on MLN Matters and Change Request transmittals released closer to the effective date. A gap between CMS's November 4 fact sheet and the operational billing instructions actually loading into your clearinghouse's edit engine is normal, but it's exactly the window where claims get rejected on a technicality that has nothing to do with medical necessity.

Frequently Asked Questions About the G2211 to Modifier B1/B2 Transition

Is G2211 going away in 2027?

Yes, as a standalone HCPCS add-on code. CMS finalized the CY 2027 Medicare Physician Fee Schedule on November 4, 2026, converting G2211 into modifier B1, which you append to the E/M code itself rather than billing a separate add-on line. The underlying concept, extra payment for an ongoing, complex care relationship, stays the same. The mechanics of billing it change completely.

What's the difference between modifier B1 and modifier B2?

Modifier B1 raises the associated E/M payment by 16% and is available to any practitioner who meets the same complexity standard G2211 used. Modifier B2 raises it by 32%, but only for practitioners in a Medicare Shared Savings Program ACO or a LEAD Model Participant Provider. B2 is voluntary, and critically, every B2 claim counts toward that practitioner's beneficiary assignment and performance-year expenditures in the ACO's shared savings math, not just toward the claim payment.

Will billing modifier B1 pay more or less than G2211 did?

It depends on the E/M level, because B1 is now a percentage of the E/M payment instead of a flat dollar amount. On a lower-level established visit like 99213, a 16% bump can land below what the flat G2211 add-on paid in 2026. On a higher-level visit like 99215, the same 16% produces a noticeably larger bonus than the old flat rate did. Run your own payer-mix numbers before assuming the change nets out even.