2027 ICD-10-CM Diagnosis Code S39.012AStrain of muscle, fascia and tendon of lower back, initial encounter
S39.012A is a billable ICD-10-CM diagnosis code for strain of muscle, fascia and tendon of lower back, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 562 through 563, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.
Code Identity
Code Classification
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 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to S39.012A: its own notes plus those printed at S39, block S30-S39, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- injuries to the abdominal wall
- injuries to the anus
- injuries to the buttock
- injuries to the external genitalia
- injuries to the flank
- injuries to the groin
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- sprain of joints and ligaments of lumbar spine and pelvis (S33.-)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Code Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
Notes
General instructions on how these codes are used.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category S39
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name S39.012A, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming S39.012A: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming S39.012A: its condition is not part of those codes, and both may be reported when the patient has both.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 S39.012A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S39.012AOverview
What is the ICD-10 code for strain of muscle, fascia and tendon of lower back, initial encounter?
The ICD-10-CM code for strain of muscle, fascia and tendon of lower back, initial encounter is S39.012A (sometimes written as S39012A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is S39.012A (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, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in S39.012A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for strain of muscle, fascia and tendon of lower back, such as an emergency visit or first evaluation.
What MS-DRG does S39.012A group to?
When strain of muscle, fascia and tendon of lower back, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 563, 964, 965, 562, 963, with relative weights from 0.8982 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S39.012A?
Under the General Equivalence Mappings, strain of muscle, fascia and tendon of lower back, initial encounter converts to ICD-9-CM 848.8 (sprain NEC). The mapping is approximate, so confirm the match fits the documentation.
