In one paragraph: A medical coder reviews a patient's documented care and assigns standard codes to it: ICD-10-CM codes for the conditions treated, and CPT or HCPCS Level II codes for the services performed (ICD-10-PCS for hospital inpatient procedures). US insurers pay, deny or audit claims on the strength of those codes, so the coder's job is to capture everything the documentation supports and nothing it does not.
What does a coder's working day look like?
Coders in Pune's RCM companies usually work through a queue of charts assigned by specialty. You open a record in the client's system, read the physician's note, decide the codes, check them against edits and payer rules, and move to the next chart. Your output is measured two ways: how many charts you complete, and how many of them pass a quality audit. New coders are trained to value accuracy over speed, because an audit failure costs more than a slow day.
Some days include feedback sessions with a quality analyst, client updates about new payer policies, or a query sent back because the documentation was unclear. It is quiet, focused desk work.
A worked example from the emergency department
Below is a simplified wound repair case of the kind ED and surgical coders see every day. It shows why coding is about rules, not searching.
"Patient fell on gravel. 3.2 cm laceration of the scalp, cleaned and closed with single-layer sutures. 2.1 cm laceration of the right forearm, layered closure performed."
| Code | Set | Why |
|---|---|---|
| 12031 | CPT | Intermediate (layered) repair of an extremity wound, 2.5 cm or less: the forearm |
| 12002-59 | CPT | Simple repair of the scalp wound, 2.6 to 7.5 cm, reported with modifier 59 because it is a different repair classification (payers may require XS instead) |
| S01.01XA | ICD-10-CM | Laceration without foreign body of scalp, initial encounter |
| S51.811A | ICD-10-CM | Laceration without foreign body of right forearm, initial encounter |
A common beginner mistake is to add the two lengths together (5.3 cm) and report a single intermediate repair. CPT allows lengths to be added only for wounds in the same classification and the same anatomic group. Here the repairs are different classifications, so they are reported separately, with the more complex repair listed first. That one rule changes what the hospital is paid, and it is exactly the kind of detail employers test in interviews.
Which code sets will I use?
- ICD-10-CM for diagnoses and reasons for care, in every setting. Updated each 1 October; the FY2027 update applies from 1 October 2026.
- CPT® for services by physicians and other providers, published by the American Medical Association and updated each 1 January.
- HCPCS Level II for drugs, supplies, equipment and some services, maintained by CMS.
- ICD-10-PCS for procedures during US hospital inpatient stays, maintained by CMS.
- Modifiers that clarify circumstances such as a separate site, a repeat procedure or a bilateral service.
What rules do coders follow?
The code books are only half the job. Coders apply the ICD-10-CM Official Guidelines for Coding and Reporting, CPT section guidelines, CMS's National Correct Coding Initiative (NCCI) edits, Medicare coverage policies, and each client's payer rules. They must also protect patient data under HIPAA and follow an ethics code such as AHIMA's Standards of Ethical Coding. Coding to maximize payment rather than to reflect the record is a compliance risk that the HHS Office of Inspector General actively pursues.
Where is coding done?
Coding happens for physician practices (professional fee), hospital outpatient departments and emergency rooms (outpatient facility), hospital admissions (inpatient), and health plans reviewing chronic conditions (risk adjustment). Each setting uses the same code sets but different guidelines and payment systems, which is why coders specialize. Learn how these connect to pay on the Pune salary page.
Questions people ask
Is medical coding related to computer programming?
No. "Coding" here means assigning classification codes to medical information. There is no software development involved.
Do medical coders talk to patients or doctors?
Coders do not talk to patients. In India they rarely talk directly to US physicians; when documentation is unclear, questions go through a query process managed by the client or a documentation specialist.
Why is medical coding outsourced to Pune?
US providers need large numbers of trained coders. Pune offers a big graduate pool, strong IT and ITES infrastructure and experience in secure healthcare processing, so many revenue cycle companies run coding teams here.