CMS & Medicare Guide
Medical Coding Updates: The Complete Guide to When and How Codes Change
ICD-10-CM, PCS, CPT, HCPCS, NCCI and CMS payment rules all change on different cycles. This guide maps the coding year so you know what to watch and when.
In this article
Coding does not change once a year — it changes on several overlapping cycles, each owned by a different organization. Knowing which cycle a change belongs to tells you where to find the official source, when it takes effect, and which claims it touches.
Who publishes which changes?
| Code set or rule | Maintained or published by | Typical cycle |
|---|---|---|
| ICD-10-CM (diagnoses) | CDC/NCHS, with CMS | Annual, effective October 1; possible April 1 update |
| ICD-10-PCS (inpatient procedures) | CMS | Annual, effective October 1; possible April 1 update |
| CPT® (procedures and services) | American Medical Association | Annual, effective January 1; Category III released twice a year; PLA codes quarterly |
| HCPCS Level II (supplies, drugs, DME, services) | CMS | Quarterly |
| NCCI edits (PTP and MUE) | CMS | Quarterly |
| Medicare Physician Fee Schedule (MPFS) | CMS, via Federal Register | Proposed in summer, final in autumn, effective January 1 |
| OPPS / ASC payment | CMS, via Federal Register | Proposed in summer, final in autumn, effective January 1 |
| IPPS / MS-DRGs | CMS, via Federal Register | Proposed in spring, final in summer, effective October 1 |
| Coverage (NCDs, LCDs) | CMS and Medicare Administrative Contractors | Ongoing |
| Commercial payer policies | Each payer | Ongoing, usually with advance notice |
These are typical patterns. Our coding calendar lists specific dates only after an official source confirms them.
Why do the dates matter so much?
Code validity is tied to the date of service (or, for inpatient claims, the discharge date). A code that is valid on September 30 may be invalid on October 1. Payment rules work the same way: the fee schedule, DRG weights or edit table in force on the date of service governs the claim.
How a change moves from proposal to claim
- Proposal. ICD-10-CM/PCS changes are discussed at the public ICD-10 Coordination and Maintenance Committee meetings. CPT changes go through the AMA CPT Editorial Panel. CMS payment changes appear first as proposed rules in the Federal Register.
- Comment period. Stakeholders, including coders, can comment on proposals.
- Final publication. Final code files, addenda, final rules and transmittals are published with an effective date.
- Implementation. Encoders, EHRs, scrubbers, clearinghouses and payers load new tables.
- Claims. The new rules apply to claims with dates of service on or after the effective date.
Medicare versus other payers
CMS rules apply to Medicare fee-for-service. Medicare Advantage plans, Medicaid programs and commercial payers may adopt, modify or ignore a given CMS policy. HIPAA requires covered entities to use the standard code sets, so ICD-10-CM, ICD-10-PCS, CPT and HCPCS changes apply broadly — but payment and coverage rules vary by payer. Our payer updates hub labels every article by scope.
A practical update checklist
Where to go next
Source
Centers for Medicare & Medicaid Services
Read Original Source (opens in a new tab)
Additional references
Medical coding trainer and author with more than 22 years of experience, an AHIMA Approved ICD-10 Trainer, and the managing editor of MedicalCodingUpdates.com.
Educational information only. Verify coding decisions against current official guidelines, code sets and applicable payer policies. Read the full disclaimer.
