Key facts for DRG 839
- FY2027 relative weight
- 1.3780
- Higher than 38% of all MS-DRGs
- Change vs FY2026
- -4.6%
- FY2026 weight 1.4440
- Geometric mean LOS
- 3.7 days
- Arithmetic mean 4.2 days
- MDC
- 17
- Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms
- Severity level
- without CC or MCC
- Transfer policy
- Not a transfer DRG
TL;DR
MS-DRG 839 is a medical group in MDC 17 (Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms) at the base severity level of its family. CMS assigns it a FY2027 relative weight of 1.3780 with a geometric mean length of stay of 3.7 days and an arithmetic mean of 4.2. Its weight moved down 4.6% from FY2026 (1.4440). That weight is higher than 38% of all medical and surgical MS-DRGs. CMS does not split this group by severity. The v44 Definitions Manual assigns it through 3 principal diagnosis codes and 33 secondary diagnosis codes.
What changed from FY2026 to FY2027
CMS recalibrates every MS-DRG weight annually from the prior year's MedPAR claims. For DRG 839 the FY2027 relative weight is 1.3780 against 1.4440 in FY2026, a fall of 4.57%, which exceeds the 2% threshold worth re-checking in contract models.
| Metric | FY2026 | FY2027 | Change |
|---|---|---|---|
| Relative weight | 1.4440 | 1.3780 | -0.0660 |
| Geometric mean LOS (days) | 4.0 | 3.7 | -0.3 |
| Arithmetic mean LOS (days) | 4.5 | 4.2 | -0.3 |
CC and MCC family
DRG 839 stands alone: CMS does not split this base group by CC or MCC severity, so complication documentation does not move the assignment, although it still affects quality and risk-adjustment reporting.
Grouper logic (v44 Definitions Manual)
Principal Diagnosis: 3 ICD-10 codes drive assignment to this group.
| ICD-10 code | Description |
|---|---|
| Z08 | Encounter for follow-up examination after completed treatment for malignant neoplasm |
| Z5111 | Encounter for antineoplastic chemotherapy |
| Z5112 | Encounter for antineoplastic immunotherapy |
Secondary Diagnosis: 33 ICD-10 codes drive assignment to this group; the first 12 are shown.
| ICD-10 code | Description |
|---|---|
| C9100 | Acute lymphoblastic leukemia not having achieved remission |
| C9101 | Acute lymphoblastic leukemia, in remission |
| C9102 | Acute lymphoblastic leukemia, in relapse |
| C9200 | Acute myeloblastic leukemia, not having achieved remission |
| C9201 | Acute myeloblastic leukemia, in remission |
| C9202 | Acute myeloblastic leukemia, in relapse |
| C9240 | Acute promyelocytic leukemia, not having achieved remission |
| C9241 | Acute promyelocytic leukemia, in remission |
| C9242 | Acute promyelocytic leukemia, in relapse |
| C9250 | Acute myelomonocytic leukemia, not having achieved remission |
| C9251 | Acute myelomonocytic leukemia, in remission |
| C9252 | Acute myelomonocytic leukemia, in relapse |
Documentation and denial exposure
As a medical DRG, assignment depends on the principal diagnosis sequenced from the attending's documentation; a secondary condition sequenced first, or a symptom code in place of the confirmed diagnosis, changes the MDC or the DRG. Because this family has no severity split, review risk concentrates on medical-necessity of the admission itself and on the two-midnight benchmark. Typical inpatient denial codes for this group: CARC 16 (claim lacks information needed to group the stay), CARC 50 (the admission or procedure is judged not medically necessary), CARC 97 (a service is bundled into the DRG payment).
How QuickIntell uses DRG 839 data
QuickCode groups inpatient encounters against the current v44 logic, flags CC and MCC candidates that lack supporting documentation, and shows the weight difference across the family before the claim drops. QuickScribe captures the attending's language that supports severity, and QuickRCM works DRG-validation denials with the grouper evidence attached.
Frequently asked questions — DRG 839
What is MS-DRG 839?
MS-DRG 839 is "Chemotherapy with Acute Leukemia as Secondary Diagnosis without CC/MCC", a medical Medicare Severity Diagnosis-Related Group in MDC 17, Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms. Medicare pays inpatient stays grouped here at the hospital's base rate multiplied by the DRG relative weight.
What is the FY2027 relative weight for DRG 839?
The FY2027 relative weight is 1.3780 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 1.4440, a change of -4.6%.
What is the average length of stay for DRG 839?
CMS reports a geometric mean length of stay of 3.7 days and an arithmetic mean of 4.2 days for FY2027. The geometric mean is used for transfer-payment calculations.
What documentation supports the severity level of DRG 839?
DRG 839 is the base-severity assignment: no secondary diagnosis on the CC or MCC lists was coded, or the only ones present are excluded for this principal diagnosis. Revenue-integrity review here looks for undercapture, meaning conditions treated during the stay (electrolyte disorders, specified anemia, acute blood loss, pressure injuries present on admission) that were never documented to the specificity the lists require. A compliant query to the attending, not a coder assumption, is the only way to move a stay to the CC or MCC sibling.
Which codes group to DRG 839?
The v44 Definitions Manual lists 3 principal diagnosis codes and 33 secondary diagnosis codes for this group. Examples from the principal diagnosis list: Z08 (Encounter for follow-up examination after completed treatment for malignant neoplasm); Z5111 (Encounter for antineoplastic chemotherapy); Z5112 (Encounter for antineoplastic immunotherapy).
Is DRG 839 a post-acute transfer DRG?
No. DRG 839 is not on the FY2027 post-acute care transfer list, so the transfer per-diem policy does not apply to it.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-01. Verify against the primary file before billing or contracting decisions.
- IPPS FY2027 Final Rule Table 5 (CMS-1849-F)Version v44 FY2027 · effective 2026-10-01 · file CMS-1849-F Table 5.txtSHA-256 01003dd571c1e2f5…
- IPPS FY2026 Final Rule Table 5 (CMS-1833-F)Version v43 FY2026 · effective 2025-10-01 · file CMS-1833-F Table 5.txtSHA-256 bf8c390d14b3cd3e…
- ICD-10 MS-DRG Definitions Manual v44 (text)Version v44 · effective 2026-10-01 · file fy2027-fr-icd10-ms-drg-definitions-manual-files-v44.zipSHA-256 ae4f6c11727fe91f…
Disclaimer
This page is an operational reference compiled from the CMS IPPS FY2027 final rule (Table 5) and the v44 ICD-10 MS-DRG Definitions Manual. Relative weights are national factors; actual payment depends on each hospital's wage-adjusted base rate, add-ons, outliers and transfer adjustments. Nothing here is legal, clinical or billing advice; verify grouping against your encoder and the published CMS files.