2026 ICD-10-CM Diagnosis Code S39.012DStrain of muscle, fascia and tendon of lower back, subsequent encounter

ICD-10-CM Codes›S00–T88›S30-S39›S39

ICD-10-CM S39.012D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S39.012D is a billable ICD-10-CM diagnosis code for strain of muscle, fascia and tendon of lower back, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, subsequent encounter.

Code Identity

ICD-10-CM Code
S39.012D
Billable Status
Yes — Valid for Submission
Code Describes
Strain of muscle, fascia and tendon of lower back, subsequent encounter
Short Description
Strain of muscle, fascia and tendon of lower back, subs
Parent Code
S39.012
Strain of muscle, fascia and tendon of lower back

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS30-S39Injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals
CategoryS39Other and unspecified injuries of abdomen, lower back, pelvis and external genitals
This CodeS39.012DStrain of muscle, fascia and tendon of lower back, subsequent encounter

Present on Admission (POA)Billing

S39.012D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dislocations, sprains and strains involving multiple body regions
  • Dislocations, sprains and strains involving thorax with lower back and pelvis
  • Dislocations/sprains/strains
  • Injury of muscle of lower back
  • Injury of tendon of lower back
  • Low back strain
  • Lumbosacral strain
  • Strain of back muscle
  • Strain of fascia of lower back
  • Strain of tendon of back
  • Strain of tendon of left lower limb
  • Strain of tendon of left psoas muscle
  • Strain of tendon of lower back
  • Strain of tendon of psoas muscle
  • Strain of tendon of right lower limb
  • Strain of tendon of right psoas muscle

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Other and unspecified injuries of abdomen, lower back, pelvis and external genitals (S39). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ061
Sprains and strains, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Sprains and Strains

A sprain is a stretched or torn ligament. Ligaments are tissues that connect bones at a joint. Falling, twisting, or getting hit can all cause a sprain. Ankle and wrist sprains are common. Symptoms include pain, swelling, bruising, and being unable to move your joint. You might feel a pop or tear when the injury happens.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S39.012D to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V58.89 Other specfied aftercare
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S39.012DOverview

Is S39.012D (Strain of muscle, fascia and tendon of lower back) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report strain of muscle, fascia and tendon of lower back, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S39.012D mean?

The final character D marks a subsequent encounter: use it for routine care while the strain of muscle, fascia and tendon of lower back is healing, after active treatment has ended.

What MS-DRG does S39.012D group to?

When strain of muscle, fascia and tendon of lower back, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S39.012D exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for strain of muscle, fascia and tendon of lower back, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S39.012D?

Under the General Equivalence Mappings, strain of muscle, fascia and tendon of lower back, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.