RTM billing basics
98985 vs. 98977: reconcile conflicting RTM drafts
Direct answer
When two remote therapeutic monitoring (RTM) drafts disagree, reconcile their periods and supporting records before selecting a code. For 2026 Medicare fee-for-service, 98985 covers 2 to 15 days of musculoskeletal monitoring, meaning monitoring related to muscles, bones, and joints. Code 98977 covers 16 to 30 days. Both use a 30-day period. They are alternatives, not two charges to accumulate. A matching day count alone does not establish payment eligibility.
The Centers for Medicare & Medicaid Services (CMS) 2026 therapy-code update gives these duration bands. The 2026 final rule explains that the short- and longer-duration codes are not additive.
One monitoring period, two draft lines
Consider a hypothetical clinic billing review. This is an invented example, not a patient record or an account of a paid claim.
The clinic is reviewing an established April 1 through April 30 monitoring period. Its first export lists 12 days and candidate code 98985. A second export lists 18 days and candidate code 98977.
The biller now sees two draft device-supply lines. One person thinks the second code covers days added after the first draft.
But the second export includes six dates in May. Those dates do not belong to the April period under review. The discrepancy is the export's date range, not six additional April days.
The clinic preserves both exports and records the correction. For this example, assume the reviewer has separately verified which dates qualify. That assumption illustrates reconciliation. It is not a rule for deciding whether a particular app event counts.
What changed for 2026
CMS made the therapy-code update effective January 1, 2026. It added 98985 for the shorter musculoskeletal monitoring period and revised 98977's description.
The distinction is the number of days within a 30-day period, not the number of exercises assigned or sessions completed.
| Days established for the monitoring period | Duration match for musculoskeletal device supply | What the match does not establish |
|---|---|---|
| 0 or 1 | Neither of these two codes | That another service is billable |
| 2 to 15 | 98985 | That every other requirement is met |
| 16 to 30 | 98977 | That 98985 can also be added for the same period |
This table classifies duration only. It does not decide whether an individual record qualifies or whether a claim should be submitted.
See pages 2 and 3 of the CMS therapy-code update for the descriptions and therapy requirements.
If you need to establish the reporting period itself, use the separate guide to RTM's 30-day and calendar-month clocks. Do not build a new period around whichever code looks available.
Why the two codes cannot be stacked
In its 2026 final rule, section 32, Remote Monitoring, CMS addresses whether the new duration codes act like a base code plus an add-on.
Its answer is no. The shorter- and longer-duration codes are alternatives. Practitioners bill one appropriate code for the number of data-transmission days per 30 days.
Do not bill 98985 for the first part of a musculoskeletal device-supply period and 98977 for the rest.
That distinction matters when a clinic revises a draft. A change from one duration band to another changes the candidate code. It does not create a second device-supply claim for the same period.
This article does not set a submission date or describe how to correct an already submitted claim. Use the applicable payer process for those questions.
Reconcile the dates before the code
Here is the underlying record for the invented example. Dates are already assigned and verified for illustration. The table does not establish timestamp or qualifying-event rules.
| Dates in the exports | Number of dates | In the April 1 through April 30 period? |
|---|---|---|
| April 2, 3, 4, 5 | 4 | Yes |
| April 9, 10, 11, 12 | 4 | Yes |
| April 16, 17, 18, 19 | 4 | Yes |
| May 1, 2, 3, 4, 5, 6 | 6 | No |
The first export contains the 12 April dates. The second contains those same 12 dates plus six May dates, making 18.
For the April period, the reconciled count remains 12. Code 98985 matches that duration. Code 98977 appeared because the second export covered dates outside the period being reviewed.
The correction does not erase the May records. It keeps them out of this April decision. Nor does it establish any separate claim for May.
Record the result in a short review note. This is an illustrative record, not a validated form or CMS-required template:
Period reviewed: April 1 through April 30. Both exports retained. The 18-day export includes six May dates. The April count is 12 verified dates. Candidate code: 98985. The 98977 draft is not approved for this period. Other billing requirements remain under review.
This example resolves a specific discrepancy without inventing a rule about partial exercise sessions. If the extra six dates had belonged to April, the result could differ. The records decide, not the order in which the drafts arrived.
If your reports still disagree, identify the unresolved dates and who will review them. Keep the code decision pending. Do not choose whichever count produces a code.
Our guide to measuring home-exercise adherence explains another important distinction: an exercise record and a completed prescribed session are not interchangeable measures.
What this comparison cannot decide
It cannot classify every app event. The publicly available CMS descriptions establish duration bands. They do not answer every question about incomplete sessions, app openings, delayed uploads, or symptom-only entries.
Do not infer a qualifying day from the code number alone. Check the underlying record against the applicable coding instructions and payer policy.
It cannot establish medical necessity. CMS states that remote-monitoring services must be reasonable and necessary. A numerical duration match does not answer that clinical question.
It does not replace the other therapy requirements. The CMS update says therapists furnish RTM under a therapy plan of care. It also addresses the required therapy modifiers. Review those requirements alongside the current coding instructions.
It does not approve a management service. Device supply and treatment management are different questions. For management requirements, see RTM management minutes and live interaction.
It is not an all-payer rulebook. This comparison addresses 2026 Medicare fee-for-service. Do not assume a Medicare Advantage or commercial plan handles the codes identically.
CMS also refers readers to the 2026 coding guidelines and related instructions. This narrow comparison is not a substitute for those instructions or a complete billing review.
The decision to carry into your clinic
Use one device-supply code decision for the established monitoring period. Keep the source record and unresolved questions beside it.
For these two codes, shorter and longer duration are alternatives, not two charges to accumulate. When the record changes, review the decision rather than adding a second line.
For information about the product, see the HepBuddy overview. This article does not establish that a particular patient, device, or claim qualifies for payment.