medical-codes-guide

Scope

Offline and keyless. Each system carries exactly one release: the current ICD-10-CM and ICD-10-PCS fiscal year, the current HCPCS Level II quarter, and the current RxNorm normalized set, with an RxClass layer over it. medcode_list_systems names each release and its effective window.

Not here, so say so instead of searching for a stand-in:

• CPT / HCPCS Level I (five-digit numeric codes such as 99213). A medcode_get_code or medcode_check_code miss names them out of scope; a search simply finds nothing. Never offer a HCPCS Level II or ICD-10-PCS code as "the CPT equivalent".
• SNOMED CT, LOINC, ICD-9-CM, ICD-11, the WHO ICD-10 base, MS-DRG, and ATC drug classes.
• Prior releases and successor links. No tool maps an old code to its replacement, a diagnosis to a procedure or HCPCS code, or an NDC to a HCPCS drug code.
• Coding rules and payment. Records carry descriptions, billability, and hierarchy only. They carry no Excludes1/Excludes2 or code-first notes, no sequencing rules, no coverage policy (NCD/LCD), and no pricing.
• Drug labels and safety data. Take the NDC or drug name to the openfda server.

Identifiers

Gates

1. Choose the system from where the code came from, not from its shape. A diagnosis field is ICD-10-CM, an inpatient procedure field ICD-10-PCS, and a supply, drug, or service line HCPCS. An undotted letter plus four digits can be both an ICD-10-CM code and a HCPCS code: A0100 and J0120 come back ambiguous between ICD10CM and HCPCS, while the dotted A01.00 resolves to ICD-10-CM. When the context tells you the system, pass it.
2. A verdict holds for today and the bundled release only. medcode_check_code takes no date of service. Before validating a claim, compare its date of service with the effective windows from medcode_list_systems. When it falls outside them, report that this server cannot validate it rather than passing on today's verdict.
3. valid_billable means reportable, not correct or payable. It says the code is a complete leaf in this release. Never claim that a code pair, sequence, or claim passes coding edits or coverage on the strength of it.
4. A header is where the search starts. For valid_header or valid_not_billable, the billable code sits below. Children come one level per call, and ICD-10-CM chains run through placeholder and 7th-character levels (T36.0X → T36.0X1 → T36.0X1A), so keep walking until billable is true. Never pad a code with X or a 7th character yourself; take the child the tool returns.
5. Treat an empty class result as unknown, not as a negative finding. Class coverage is uneven across types. Lisinopril has no EPC class here, but it has the MOA class "Angiotensin-converting Enzyme Inhibitors" (N0000000181), and its products carry VA class CV800 "ACE INHIBITORS". Check the other class types before saying a drug lacks a pharmacology.
6. DISEASE classes are MeSH descriptors, not diagnosis codes. D006973 is MeSH "Hypertension". To get the ICD-10-CM code for a disease a drug may treat, search the disease name with medcode_search_codes.