ICD-10-CM Code Validity Checker by Date of Service

A diagnosis code that was billable last month may not be billable today. Each ICD-10-CM release adds codes, removes codes, and turns some billable codes into non-billable headers. Enter a code and a date of service to see whether that exact code was in the official code set in effect on that date, and whether it was billable or a header. The FY 2027 change explorer further down lists every code that changed on October 1, 2026, with its new billable or header status.

How the Date-of-Service Check Works

The date you enter decides which official ICD-10-CM release is checked. The checker currently holds three releases:

October 1, 2025 through March 31, 2026: FY 2026 release
April 1, 2026 through September 30, 2026: April 1, 2026 update
October 1, 2026 through September 30, 2027: FY 2027 release

These periods come from the CMS ICD-10 files pages. A date before October 1, 2025 or after September 30, 2027 is reported as not supported. The checker never falls back to the newest release.

Which date to enter: CMS says the FY 2027 ICD-10-CM codes are for discharges and patient encounters occurring from October 1, 2026 through September 30, 2027. For Medicare claims, the Medicare Claims Processing Manual, Chapter 23, section 10.6 says diagnosis codes must be reported based on the date of service, including the date of discharge when applicable, not the date the claim is prepared or received. The same section says CMS gives no grace period for billing discontinued diagnosis codes on Medicare claims. If the discharge date is the applicable date for your claim, enter that date. A service on September 30, 2026 is checked against the April 1, 2026 update even if the claim is sent in October. Other payers apply their own claim edits.

The code is matched exactly. You can type it with or without the dot, in upper or lower case, so E11.9, e11.9 and E119 all check the same code. Nothing else is changed: the checker never adds a placeholder X, a 7th character, or any other character. S72.001A and T40.1X1A are found as typed, but T40.1X1 is reported as a header because it needs a 7th character.

Example: I42.0 (dilated cardiomyopathy) is billable on a date of service of September 30, 2026. On October 1, 2026 it is a header, and its billable child codes are I42.00, I42.01 and I42.09. When a code’s status or official title changed between October 1, 2025 and September 30, 2027, the result says so under “Changes across the loaded versions,” so a single check shows whether the code changed.

What “Valid and Billable” Means Here

Every entry in a CMS order file carries a flag. Either the code is valid for submission on HIPAA-covered transactions, or it is a header: a category or subcategory with more specific codes beneath it. In this checker, “billable” means that flag is set for the release that applies to your date of service. For a header, the checker lists up to 25 of its billable child codes.

E11 (type 2 diabetes mellitus) is a header. E11.9 (type 2 diabetes mellitus without complications) is billable. Billable status is a code-file flag. It does not show that a code fits a particular claim. Where the code set distinguishes laterality, encounter type, or severity, the code you choose should reflect what the documentation actually states, not the closest available approximation.

Four questions are easy to confuse:

Is the code in the release? It appears in that release’s order file, either as a billable code or as a header. A code that is not in the file is reported as not in the code set.
Is it billable or a header? A billable code is flagged as valid for submission on HIPAA-covered transactions. A header is a category or subcategory with more specific codes beneath it and is not valid for submission. G35 (multiple sclerosis) has been a header since October 1, 2025.
Is it valid for my date? The code is billable in the release that applies to the date of service or discharge. The same code can be billable in one release and a header, or absent, in the next.
Is it the right code for the patient? That depends on the documentation and the ICD-10-CM Official Guidelines for Coding and Reporting. This checker cannot answer it.

FY 2027 Changes (Effective October 1, 2026)

We compared the April 1, 2026 order file with the FY 2027 order file, code by code, and checked the result against the FY 2027 addenda:

190 codes became billable. All 190 are new codes.
30 codes stopped being billable. 15 were removed from the code set: S23.420A, S23.420D and S23.420S, and twelve T52.8X- codes (T52.8X1A through T52.8X4S). The other 15 became headers.
4 codes stayed billable but had their official title revised: L02.232, L03.312, L03.322 and Z29.14.

The April 1, 2026 update itself added and removed nothing. Its order file has the same codes and the same billable and header flags as the October 1, 2025 release.

How four codes compare on September 30, 2026 and October 1, 2026:

I42.00 Dilated cardiomyopathy, unspecified: not in the code set, then billable
S23.420A Sprain of sternoclavicular (joint) (ligament), initial encounter: billable, then not in the code set
L02.232: billable on both dates, with the title revised from “Carbuncle of back [any part, except buttock]” to “Carbuncle of back [any part, except buttock and flank]”
E11.9 Type 2 diabetes mellitus without complications: billable on both dates, no change

FY 2027 Change Explorer

278 codes changed between the April 1, 2026 update and the FY 2027 release. The explorer below groups them the way the change actually affects a claim: newly billable, no longer billable, added to the code set, removed from the code set, billable codes that became headers, and codes that kept their status but had their official title revised. It reads the same CMS order files as the checker above, so a code you find here can be checked against a specific date without leaving the page.

Why Published Counts Differ

FY 2027 change totals depend on what is being counted.

Billable-code basis: 190 newly billable, 30 no longer billable. This is how the codes addenda file counts additions and deletions, and our comparison matches it.
All-code basis: 238 entries added and 21 entries removed. This counts every entry in the order file, headers included. The 238 are the 190 new billable codes plus 48 new headers. The 21 are the 15 removed billable codes plus 6 removed headers.
Order addenda basis: 253 Add lines and 36 Delete lines. The order addenda file records each code that became a header twice: once as a deleted billable entry and once as an added header. That is 238 plus 15, and 21 plus 15.
Status and title changes: 15 codes changed from billable to header, and no header became billable. 4 codes stayed billable with a revised title. Revisions are not counted as additions or deletions.

None of these figures is wrong. A code that turns into a header drops out of the billable count but stays in the order file. That is why the 30 no longer billable is larger than the 21 entries removed, and why the order addenda show more Add and Delete lines than either count.

Codes That Became Headers

These 15 codes were billable through September 30, 2026. From October 1, 2026 they are headers, with the number of billable child codes shown in brackets:

D69.1 Qualitative platelet defects (2)
I42.0 Dilated cardiomyopathy (3)
I42.8 Other cardiomyopathies (2)
I49.8 Other specified cardiac arrhythmias (3)
M72.2 Plantar fascial fibromatosis (3)
M86.8X1 through M86.8X8 Other osteomyelitis: shoulder, upper arm, forearm, hand, thigh, lower leg, ankle and foot, and other site (3 each)
Z68.1 Body mass index [BMI] 19.9 or less, adult (2)
Z87.890 Personal history of sex reassignment (5)

A claim with one of these codes and a date of service on or after October 1, 2026 uses a header rather than a billable code. Enter the header in the checker to see its child codes.

Questions People Ask About the FY 2027 Update

Is this ICD-10-CM code valid for my date of service?

Enter the code and the date in the checker at the top of this page. The date decides which release is read, so a code can come back billable for one date and a header, or absent, for another. For an inpatient claim, use the date your claim reports, including the discharge date where that applies.

What changed in ICD-10-CM for FY 2027?

190 codes became billable, 30 stopped being billable, 238 entries were added to the order file, 21 were removed, 15 billable codes became headers, no header became billable, and 4 codes kept their status with a revised title. The change explorer lists each of those codes.

When do the FY 2027 codes take effect?

CMS states that the FY 2027 ICD-10-CM codes are for discharges and patient encounters occurring from October 1, 2026 through September 30, 2027.

Does a new ICD-10-CM code mean it is billable?

No. Of the 238 entries added for FY 2027, 190 are billable codes and 48 are headers. A header is a category or subcategory with more specific codes beneath it, and it is not valid for submission. I42.0 (dilated cardiomyopathy) is the reverse case: it stayed in the code set but became a header, with I42.00, I42.01 and I42.09 beneath it.

Why does one published change count differ from another?

Because the counts measure different things: billable codes, every entry in the order file, or lines in the addenda files. The three bases are set out under Why Published Counts Differ, and none of them is wrong.

Can I use an FY 2027 code before October 1, 2026?

Not for a date of service in the earlier period. For Medicare claims, CMS instructs that diagnosis codes be reported based on the date of service, including the date of discharge when applicable, and states that it gives no grace period for billing discontinued diagnosis codes. Other payers apply their own claim edits, so confirm anything payer-specific with that payer.

What This Tool Does Not Check

The checker reports coding-file status only. It does not check:

clinical appropriateness of a diagnosis
medical necessity for a service
code sequencing under the ICD-10-CM guidelines
documentation sufficiency
payer-specific edits
coverage
which 7th character fits the encounter clinically

It also does not suggest a replacement for a deleted code. Treat the result as a quick reference, not as a replacement for the official code set, your payer’s medical policy, or the judgment of a certified coder.

Common Coding and Claim Denial Issues

Diagnosis codes contribute to denials in a few recurring ways: submitting a category header instead of a billable code, choosing a code the documentation does not support, using a code that was deleted or revised in a later annual update, or pairing a diagnosis with a procedure the payer does not consider medically necessary for that condition.

None of these are visible from the code alone. They surface when the claim is adjudicated, which is why it is worth confirming the description and billable status before submission rather than after a denial.

Sources and Data Versions

The data comes from the CMS “Code Descriptions in Tabular Order” files listed on the CMS ICD-10 page. For each release we loaded the order file, which includes headers, and confirmed that its billable count matches the separate codes file exactly:

FY 2026 release (2026-code-descriptions-tabular-order.zip): 98,186 entries, 74,719 billable, 23,467 headers
April 1, 2026 update (april-1-2026-code-descriptions-tabular-order.zip): 98,186 entries, 74,719 billable, 23,467 headers
FY 2027 release (2027-code-descriptions-tabular-order.zip): 98,403 entries, 74,879 billable, 23,524 headers

The change explorer is built from the same two releases: it lists 278 codes, made up of 190 newly billable codes, 48 new headers, 15 removed billable codes, 6 removed headers, 15 codes that became headers and 4 title revisions. The FY 2027 change counts above come from comparing the April 1, 2026 and FY 2027 order files, checked against the codes addenda and order addenda files in the same CMS download. ICD-10-CM is the U.S. clinical modification of the World Health Organization’s ICD-10. It is developed and maintained by the CDC’s National Center for Health Statistics and adopted by HHS as the HIPAA diagnosis code set. Data last checked: September 17, 2026.

Related Coding Resources

If a diagnosis code is being denied rather than simply hard to find, these guides cover the adjacent ground: the complete CPT codes guide for 2026 for the procedure side of the claim, why medical coding errors cost practices money, and what happens when an ICD-10 code is deleted and claims start failing against it. For the full set of checks a claim should pass before submission, see what makes a clean claim.